August 2005 Archives

The area’s lack of rain over the past half year is one for the books. Not even the paltry precipitation of the Dust Bowl years back in the 1930s can match the totals tallied over the combined Meteorological Spring and Summer period which came to an end overnight. Over the six months which began this past March 1 and ended as September arrived, a mere 9.75” of rain fell at Midway Airport—less than half (44%) the typical amount and more than a foot (12.65”) below normal! That makes the 2005 growing season the driest of any since weather records began at the South Side site 77 years ago in 1928. The last time a growing season here came close to being that dry was in the Dust Bowl Year of 1934 when 10.20” fell.

It hasn’t rained measurably in the city for the past 11 days marking the first time since 1969 that August’s closing 11 days were rain-free.

The Labor Day holiday looks beautiful with comfortable temperatures and humidities.
-Tom Skilling

August’s close Wednesday night brings Meteorological Summer, 2005 to an end. The season featured three consecutive months of warmer than normal temperatures and pitifully little rainfall. The 74.7° average temperature over the period which began June 1 is 3.1° warmer than the long term average and 6.1° above the same period a year ago. Rainfall was woefully limited. O’Hare’s 5.18” ranks third driest of the 135 years for which records exist. In the city, Midway Airport’s 4.58” is the driest since measurements began at the South Side location in 1928. The previous driest meteorological summer there occured in 1991 when just 4.97” fell.
Our warm, dry summer may have some implications in the months ahead. Six of seven previous years with similar trends in temperature and precipitation have been followed by less than average snowfall in the cold months which follow.

Katrina, once the bearer of 175 mph winds and 47-foot waves in the Gulf of Mexico, weakened to a tropical storm late Monday. Though likely to remain a prolific rain and tornado producer on Tuesday, the once Category 5-intensity system offered little prospect for rain to Chicago. Instead, its flooding downpours will drench the Ohio Valley area, where rainfalls could exceed 2” and flood watches are in effect.
Katrina produced one of the four lowest barometric pressure readings ever recorded in an Atlantic basin hurricane (902 mb. 26.63”) Sunday before roaring onto the southeast Louisiana coast at 6:10 a.m. Monday—and landfalling a second time at the Louisana/Mississippi border. By evening, the storm’s central pressure had increased from 26.63” to 28.73”—underscoring the speed with which it was losing strength.
Blistering heat gripped the West Monday. Temperatures topped 100° and established a new record at Havre, Montana (102°).

Hurricane warnings have been up for some time as the eye of Hurricane Katrina hits mainland this morning and the storm blasts the Gulf Coast from Louisiana to the western edge of the Florida Panhandle preceded and accompanied by heavy rains, severe weather, and winds well in excess of 130 m.p.h. A storm surge of 15 to nearly 30 feet combined with 5 to 10 inch rainfall totals will result in widespread flooding. The storm is a monster with hurricane-force winds (75 m.p.h.) extending 100 miles from the eye, and tropical storm-force winds (40-74 m.p.h.) another 130 miles out. Katrina’s winds are comparable to a strong F2 (113-157 m.p.h.) or F3 (158-206 m.p.h.) tornado raging for hours on end.
As the storm moves inland and weakens, tracking north and then east up the Ohio River Valley, an extensive area of rain will spread perhaps as far north as Chicago before taking the turn east. Fair skies should prevail the last half of the week in northeast Illinois.

While Chicagoans contemplate the 15th anniversary of the deadly Plainfield tornado, Gulf coast residents from Louisiana to the western end of the Florida panhandle brace for Hurricane Katrina. With the storm centered in the Gulf of Mexico some 350 miles south of the mouth of the Mississippi River Saturday evening, the National Hurricane Center highest landfall probabilities targeted the eastern Louisiana coast close to New Orleans Monday. At that point Katrina could carry winds in excess of 125 m.p.h. and bear torrential rains and a storm surge threatening extensive flooding over low-lying areas. The direction of movement after landfall will significantly influence Chicago weather during the week ahead. Monday heavy rains should cover portions of the lower Mississippi Valley and accompanying the remnant low center up the Ohio Valley mid-week. As the low makes a turn to the east, the best chance of rain in NE Illinois and NW Indiana will be Tuesday night and Wednesday.

For nearly 24 hours Friday, Key West, Fla., was blasted by Hurricane Katrina’s wind and torrential rain. Downpours were still in progress as night fell with winds gusting to 47 m.p.h. The 9.52” of rain since late Thursday was the greatest 24-hour total of any summer day there since 1871. Winds as high as 74 m.p.h. were reported on the Keys during the day—even a tornado. Several offshore buoys just north reported gusts to 104 m.p.h. More than a foot of rain (13.24”) fell at Homestead Air Force Base south of Miami.
Chicagoans enjoy the 13th and final weekend of meteorological summer Saturday. Eight of the first 12 weekends were warmer than normal—and this weekend will be as well. Summer weekends here have averaged more than 7 degrees warmer than average.
Sunday marks the 15th anniversary of the deadly Plainfield tornado, which hit at 3:45 p.m. on a hot, humid Aug. 28 afternoon in 1990, killing 29.

The final weekend of Meteorological Summer, 2005—which began June 1—is likely to end as the season began—warm. Not only are 30 daytime 90s on the books to date at Midway Airport and 22 at O’Hare (compared to just three last year), but 76% of days over the three month period have been warmer than normal. The season ranks 10th warmest of the 135 on record here since 1871. The 74.8° average is 3.2° above the long term average of 71.6°.
Hurricane Katrina’s downpours aren’t the only ones dousing sections of the U.S. Portions of Kansas have been walloped in the past two days by more than 6” of rain, continuing a trend which has dominated the summer there. Chanute recorded 6.42” of rain while Emporia was hit by 4.16”.
Any sunlight here Friday will aid in daytime heating. With higher humidities in place, some heavy t-storms threaten late in the day or Friday night.

Tom Skilling autographing a baseball for a Cubs charity auction

Tom Skilling being interviewed on WGN Radio by Pat Hughes and Ron Santo

Tom Skilling warming up in the singer's bullpen moments before rendering his melodious version of the 7th Inning-Stretch with the WGN-TV Weather Team

Are you ready Cub Fans? A one a two...

One, two, three strikes you're out!

WGN WEATHER TEAM STORMS WRIGLEY

On Wednesday afternoon August 24 Tom Skilling and the WGN/Chicago Tribune weather team were bestowed the honor of singing Take Me Out to the Ball Game during the seventh inning stretch of the game between the Cubs and the Atlanta Braves. The weather was spectacular with plenty of sunshine, comfortable temperatures in the 70s and a refreshing northeast wind blowing in from center field. Unfortunately a fine pitching performance from Mark Prior went to waste as a late inning rally allowed the Braves to defeat the Cubs 3-1.

Aside from that, it was a wonderful day, one that none of us will ever forget- singing the seventh inning stretch at Wrigley Field.

The Weather Team warming up before the game.
L to R: Paul Dailey, Tom Valle, Tom Skilling, Steve Kahn, Nelson Taruc, Bill Snyder

The Whole Gang
L to R: Deanna Kahn, Steve Kahn, Diane Dailey, Paul Dailey, Tom Skilling, Jeanne Valle, Tom Valle, Cara Hansen, Nelson Taruc, Bill Snyder, Liz Valliyil

Tom autographing a baseball for a Cubs charity auction

Tom being interviewed on WGN Radio by Pat Hughes and Ron Santo

Talking with Ron and Pat between innnings

Tom warming up in the singer's bullpen

Waiting to sing

Are you ready Cub Fans? A one a two...

One, two three strikes you're out

The past three days have seen high temperatures across northeast Illinois fail to warm out of the 70s and today could be number four.
However, the strong Canadian high pressure air mass responsible for this cool down is slowly receding to the east. By this weekend the return of southerly flow should allow readings to once again approach the 90° mark. Warm humid conditions are then expected to persist into the middle of next week before computer models indicate the next cool off will occur.
Severe weather reports were few and far between Wednesday, but late in the afternoon Higgins, Oklahoma was hit with baseball-sized hail. Tropical Storm Katrina is slowly intensifying as it approaches the east-central coast of Florida, and latest forecasts have it reaching Hurricane strength just before making landfall later tonight. 10 to 15 inch rains could drench southern and central Florida.

Chicago’s temperatures remain below 80° for a third consecutive day Wednesday. With highs of 73° Monday and Tuesday—and a 77° high predicted this afternoon, the area is in the midst of its coolest spell in nearly two months.
A series of sub-80°days in August’s final two weeks occur on an average only once every three years.
The chill’s been most noticeable at night across the Upper Midwest. Embarrass, Minnesota slipped to 29° early Tuesday. Other lows included 34° at Bayfield and 36° at Hayward —each in northern Wisconsin. Chicago’s western suburbs have hosted low 50° lows but warming breezes off Lake Michigan’s 72° waters have limited cooling in the city to the low/mid 60s.
Cool as its been here, snow advisories were posted above 6,500 feet in northwest Montana overnight. Rains of 2.29” hit Tucson, Arizona Tuesday, the heaviest there in 22 years.

There haven’t been many days this summer quite like Monday. A reading cooler than Chicago’s 73° official high has occured this season on only four other days since June 1. It was the city’s lowest daytime maximum in nearly two months since June 18, and equalled the area’s normal high on Sept. 17-19. While only five days this summer have failed to break above 73°, last summer’s chill had produced 21 such days by this point in the season.
The cold Canadian air mass also produced lows of 35° in northern Minnesota’s Embarrass and in Osceola in northwest Wisconsin. Frost advisories were in effect overnight in sections of interior Upper Michigan.
Tropical Storm Jose formed west of Mexico’s Yucatan Peninsula over the Bay of Campeche Monday. Its peak winds reached 50 m.p.h., but, the system’s steady westward movement limited its time over the the warm tropical ocean waters curtailing further development.
--Tom Skilling

Taking a cue from this week’s school year start-up in many suburban areas, the season’s first autumnal chill will arrive in Chicago today amidst gusty north winds and a cloud-filled sky. After one of the hottest summers in recent years, light jackets and sweaters will be in order tonight and early Tuesday as temperatures drop into the 50s. With a bit more sun, readings will rebound into the middle 70s Tuesday, and by the end of the week summer will be back in control with the mercury once again pushing the 90º mark.
While the record early season activity in the tropical Atlantic Basin has quieted down, and the area is currently storm free, Japan is bracing for a direct hit from Typhoon Mawar.
Passing near the island of Iwo Jima Sunday night, the typhoon is forecast to make landfall on the central Japan coastline between Osaka and Tokyo on Wednesday with winds as high as 140 m.p.h.

Welcome thunderstorms rolled through the entire rain-starved Chicago area early Saturday, but it was the north side that harvested most of the beneficial rainfall with many areas totaling between one and two inches. Officially, O’Hare measured 1.35 inches of rain, the largest one day rainfall there since last August 28 when 1.41 inches fell. Southern areas were not as fortunate with rainfall tallies sharply tapering off to less than one quarter inch. With drier air now moving into the area, it appears that the rain spigot will be turned off until at least the end of the week.
The next few days also promise to be quite cool having an autumnal-like feel to them, giving the city a preview of rapidly approaching meteorological fall which begins in less than two weeks on September 1. Daytime highs should remain in the 70s Monday and Tuesday, and aided by clear skies and lengthening darkness, overnight lows could approach 50º in the coolest inland suburbs.

Thundery downpours greet Chicagoans Saturday morning associated with a system which produced twisters Friday in Kansas and driving rains over sections of western Illinois. Totals north of St. Louis in McDonough County, Ill., reached 2.50” by nightfall Friday—much of it falling in only 30 minutes. An average of 24 computer projections indicates Chicago rainfall could reach 0.87”—but may range from as little as 0.75” in some areas to as much as 2” in others before winding down later Saturday.
More information is emerging on Thursday’s southern Wisconsin tornadoes. The deadliest of the nearly three dozen twisters—the Stoughton, Wis., storm—touched down at 6:05 p.m. Thursday and may have been on the ground 45 to 55 minutes, traveling very slowly by tornado standards—perhaps just 15 to 20 m.p.h., half a typical tornado’s forward speed. There has never been a stronger twister as far south in Wisconsin in August.

As many as two dozen twisters raked sections of 14 Wisconsin counties late Friday in that area’s worst single outbreak of severe weather this year. By nightfall, authorities confirmed at least one fatality and six injuries in hard hit Stoughton, just southeast of Madison. But damage was widespread across state, in a broad corridor from near LaCrosse east to Lake Michigan. There were reports of shingles and debris falling from thunderstorms—which towered to fifty thousand feet—as they swept through Jefferson County and the nearby Milwaukee area.
Earlier, waves of thunderstorms produced blinding downpours in some of Chicago’s far northwest suburbs. Belvidere was swamped for a time by 3.50” while Woodstock in McHenry County was hit with 2” and Rockford’s 2.23” tally set a new record for August 18.
Thursday’s rains continued to help reduce the severity of this summer’s drought in Illinois.

The sun’s been rising later and setting earlier in the nearly two months since summer’s official open in June. It’s a process which whittles away at the number of hours of sunlight each year—very slowly at first, then at a faster pace. While sunset took place at 8:29 p.m. in late June, it will set at 7:49 p.m. Wednesday evening. The city receives one hour and 26 minutes less sunlight Wednesday than just 57 days ago on June 21. Another four hours and 39 minutes disappears by the official start of winter at 12:35 p.m. on December 21.
Shorter days haven’t yet eliminated the chance for hot weather. Low 90s return Friday, the eastern extension of an air mass which boosted temperatures at Billings, Mont. from 61° Saturday to 92° Tuesday. Powerful Montana and Utah thunderstorms proved such prolific hail producers, 3” of the icy stones covered the ground in their wake Tuesday evening.

The torrid pace at which this summer’s 90s have been accumulating in Chicago has slowed. But, 90° temperatures probably aren’t history yet. South winds send temperatures soaring toward 90° for a day later this week. And, weather records reveal an average of three additional 90s have occurred beyond August 16 in years with drought conditions similar to those currently in place—in a few of those years as many as seven.
Record rains brought an end to the blistering heat through which New Yorkers suffered this past weekend. Downpours totaled 3.50” at LaGuardia Airport Sunday—a deluge which reduced temperatures from 100° Saturday to just 77° Monday—a 23° drop. And, heat and humidity spawned a new round of flooding rains which accompanied Missouri thunderstorms Monday. As much as 3.54” fell as Osage Beach, Missouri and a record-breaking 2.67” at Joplin.
-Tom Skilling

This weekend’s back-to-back highs in the 70s brought an end to the city’s two-month string of warm summer weekends. Not since Father’s Day weekend have temperatures here failed to reach the 80s on at least one day of the weekend. Though Saturday’s showers shifted south of the city on Sunday, an abundance of cloudiness coupled with northeast winds helped suppress the temperatures. Highs are expected to return to the lower 80s today with increased sunshine and should remain there through most of the upcoming week. Our recent rainy weather will take a brief respite and is not expected to return until late in the week.
Severe weather erupted Sunday afternoon in the lower Ohio Valley as a line of severe thunderstorms swept across areas from southeast Missouri to southern Indiana, downing trees and power lines. Winds were clocked up to 60 m.p.h. at Harrisburg and 70 m.p.h. at Simpson—both in southeast Illinois.

After a hot summer with endless strings of sunny dry days, things seem to be beginning to change. In recent days rain has been falling at more frequent intervals and a persistent cloud cover has been keeping hot weather at bay. A frontal system stalling out downstate should prevent the 90s from making inroads into the area this week and while showers will exit this area this morning, more rain should return by Thursday as the next system approaches.
While droughts that take months to develop usually don’t end quickly, the combination of frequent rainfall and cooler cloudier weather that limits moisture evaporation from the soils will begin to make slow steady inroads into soil moisture replenishment.
The Atlantic remains active with Tropical Storm Irene forecast to gain hurricane strength today before recurving out to sea, making way for the season’s tenth storm Jose expected to be named later today about 1000 miles east of the Lesser Antilles.

It was hot downstate Friday. Triple-digit temperatures dominated the scene. Highs of 100° at both St. Louis and Belleville marked the fourth time in 2005 that daytime readings reached the century mark there.
Only a year ago, jackets and sweaters were in fashion across the region as Midwesterners shivered through one of the summer’s many cool spells. The Aug. 12, 2004, high in St. Louis, as an example, topped out at just 69°—a reading 31 degrees below Friday’s sizzling 100° maximum.
A year-to-year comparison at Chicago between last year’s 62° high and the 85° reading achieved Friday was equally dramatic.
There’s been no shortage of warm air in Chicago this season. Friday’s 85° high was the 51st daytime reading as high or higher since June 1. At no time since records began here in 1871 has a meteorological summer hit 85° or higher as frequently. The closest was 1988 with 50 days of 85°-plus highs.

Chicago Tribune photographer John Smierciak was kind enough to share these lightning images with the WGN Weather Center. The photos were taken early in the evening of July 19 in St. John, Ind. Thank you John for your amazing photos!

Photos courtesy of Chicago Tribune photographer John Smierciak

Chicago’s south suburbs recorded the area’s heaviest rainfalls Thursday in the first of what will be a series of thundery spells over the next few weeks. Temperatures soared to within striking distance of 100° downstate at the same time that dew points, which reflect atmospheric moisture levels, reached the mid 70s—levels typical of a tropical rain forest. It proved an explosive mix and produced thunderstorm clusters which drenched Mokena with 1.50” of rain. Totals exceeded 1.00” at Joliet and Romeoville. Midway Airport’s 0.51” was the heaviest there in two weeks.
Though Chicago’s northern suburbs missed out on the first wave, radars tracked the approach of a new round of showers and thunderstorms late Thursday.
Were Chicago to receive measurable rain at some point each day through Monday, it would mark the first time since January that five consecutive days recorded precipitation.

Hail and thundery downpours pelted the Plains late Wednesday and are heading for Chicago. The clouds responsible towered 10 miles above the terrain, and may be the first in a series to sweep the nation’s heartland in coming days. Rain won’t fall continuously. In fact, rain-free interludes are a good bet. But when the downpours do come, they may produce some impressive rainfalls here. Unfortunately, the clouds responsible threaten to obscure much of Thursday night’s annual Perseid’s Meteor shower.
Warm weather continued Wednesday. O’Hare’s 90° high was the 22nd of 2005. August’s opening 10 days rank third warmest since observations began at the site in 1959.
In contrast to Chicago’s recent heat, snow fell “down under” earlier this week. It’s winter in Australia—but snow isn’t common in Victoria or its state capital of Melbourne. The flakes there were the first since 1986 and the heaviest since 1951.

For the 30th time in 2005, temperatures at Midway Airport exceeded 90° Tuesday. The day’s high of 95° at both Midway and O’Hare—just 2 degrees shy of the 1913 record of 97°—tied as the city’s fourth warmest temperature to date. The warmest here has been 102° on July 24. An Aug. 9 hasn’t been warmer in 61 years—since a 97° high in 1944.
Tuesday’s heat pushes the average temperature at Midway Airport since June 1 to 77.4°, a reading 4.4 degrees above normal and advances the Meteorological Summer 2005 season to a ranking of 2nd warmest since 1928. Though heat relief is on the way, history strongly suggests Chicagoans haven’t seen the last of 90° temperatures. In previous comparably dry summers, an average of seven additional 90s have occurred beyond Aug. 10.
Every reporting station in the metro area reached or exceeded 90° Tuesday. Interestingly, the hottest area readings were at Rockford and Kenosha—both 97°.

Not since 1983 have the opening eight days of August failed to produce measurable rain at either of the city’s official weather observation sites. And while there are growing signs rain may appear on the scene over the coming week, Chicago’s rain deficit has grown to 10.12” since March 1. The dry weather’s impact has been devastating on the region’s corn crop. While some pockets of timely rainfall put some fields in better shape than others across northern and central Illinois, the latest USDA crop condition report rates 61% of Illinois’ corn crop in “poor” or “very poor” condition—the worst of any state in the Midwest.
Limited soil moisture contributed to low humidities amid Monday’s soaring Chicago readings. The area’s average daytime relative humidity of 54% was lower than the 69% average in perennially dry Phoenix, Ariz. The mercury climbed past 90° for the 29th time in 2005 at Midway (93°) and the 20th time at O’Hare (93°) Monday.

Yesterday, Midway hit 90° for the fifth time this month, and it looks like three more 90° days will be added to that total by midweek. Humidity will also slowly be on the rise. Showers and thunderstorms appear in the forecast each day starting Wednesday through next weekend. While the core of the jet stream still resides far to the north across southern and central Canada, light westerly winds aloft at this latitude allow low-level southerly flow to feed warm, moist air into northern Illinois. A cool front will sag south through Wisconsin, drifting through Chicago on the heels of a thunderstorm-producing low pressure center Friday. From that point on, the front will become quasi-stationary, with the potential to fluctuate north or south of the metro area. Current computer model projections have the front situated just south of Interstate 80 next weekend, but a slight repositioning to the north could radically change temperature and rainfall forecasts.

Heat and humidity return with a vengeance this week, accompanied by a significantly enhanced probability of thunderstorms.
With the jet stream situated far to the north across southern Canada and weak west-east flow aloft, warm southerly surface winds will return this week, feeding low-level moisture into northern Illinois. Heat indices will rise well into the 90s Monday before crossing the 100° threshold Tuesday and Wednesday. Clouds Thursday may hold the heat index in the 90s, but the highest reading of the week may be reserved for Friday. Any three consecutive days of a 100° heat index will trigger a heat warning for Chicago.
Slow-moving upper-level troughs aloft riding over warm humid air in combination with a nearly stationary front to the north may create periods of showers and thunderstorms Thursday and again late Friday into Saturday. Before the week is up, copious rains could fall over central and northern Wisconsin.

The summer’s tenacious drought has been a disaster for area farmers, and has left lawns and gardens parched and dry. But, in terms of weekend weather which cooperates with outdoor activities, 2005 has few recent meteorological peers. Measurable rain has fallen on only three weekend days—15 (83% of them) have been dry. And the rains which have fallen on the weekend have been negligible—totaling only 0.43”! But heat has been the big story. All but one of the nine weekends currently on the books have been warmer than normal. Summer weekends have produced highs averaging 6.5 degrees above normal, including 2005’s hottest single temperature: 102° on July 24. Readings have exceeded 90° on six of the 18 weekend days of summer to date.
The humidity decline responsible for comfortable conditions Friday continues Saturday. But humidities begin creeping higher Sunday ahead of a new hot spell due next week.

Active as the 2005 hurricane season has been with its eight named storms to date and a ninth apparently on the way in the Atlantic over the next day or two, the worst may be yet to come. The second forecast in a week to boost the number of expected Atlantic tropical storms and hurricanes was released Thursday by Dr. William Gray and Philip Klotzbach of Colorado State University. It suggests as many as 12 additional named tropical storms are on the way, eight of them hurricanes. It’s a tally which comes close to the all time record of 21 named storms in 1933.
Gray cites seven seasons as having characteristics similar to the current one including: 1886, 1933, 1966, 1995, 1996, 2003 and 2004. Each produced at least at least one Category 4 (with 130-155 m.p.h. winds) beyond August 5. Gray estimates the chance of a major hurricane striking the U.S. mainland is 77%.

Temperatures head toward 94° in Chicago Wednesday. It’s only the third time since 1970 the three opening days of August have each posted a 90° high.
Thunder is to rumble over sections of the area Wednesday afternoon and evening. Early indications are the storms may affect 40 to 60% of the Chicago metro area on what promises to be the hottest and most humid day of the current hot spell. With nearly 2” evaporated water in the air above Chicago, any thunderstorms Wednesday could be prolific rain producers where they occur because they are likely to be slow movers.
Dry soils limited atmospheric moisture levels Tuesday--as reflected by low 60° dewpoints at the time of Tuesday’s afternoon 92° high. Dewpoints in the low 60s produce a moderately humid feel—but are well below the truly muggy, oppressive feeling 70°+ dewpoints which dominate the Gulf Coast region.
The result was a peak heat index of just 93° Tuesday.

Tropical forecasters at NOAA increased the forecast for total 2005
tropical storms and hurricanes in the Atlantic Basin, suggesting the
current season may produce a record 18 to 21 named storms--including 9
to 11 hurricanes. On average, only six hurricanes occur in the Atlantic
Basin.

Hot weather continues Tuesday. A 25th day of 90° temperatures is predicted at Midway Airport. That’s more than six times all of last year’s 90s at the site (there were only four of them). It’s also the most 90s to occur in Chicago by August 2 since the 31 at this point in the infamous Summer of 1988—a year which included a drought responsible for devastating crops across the nation’s heartland.
Hot as this August’s opening days are, the readings pale in comparison to the highs and lows recorded during the month’s opening four days in 1988—100°/78°, 100°/79°, 95°/79° and 97°/78° respectively.
Tucson, Arizona just finished its hottest July ever—and the city’s hottest single month on the books since 1895. Not only did the city endure 39 consecutive 100°+ days—a string of hot days which began in June—but July closed with an average temperature of 90.6°