Chicago’s October temperatures undergo the second-largest monthly decline of the year,
surpassed only by November.
EXTREME MINIMUM SUNSPOT ACTIVITY
Astronomers who keep tabs on sunspots—the dark blotches usually scattered across
the sun’s surface—have observed a recent extreme minimum of sunspot activity.
Sunspots run in 11-year cycles, but the current lull is exceptional (though not without
historical precedent). As of Sept. 27, NASA scientists report that the sun has been
absolutely blank—no sunspots at all—for 200 days in 2008.
NASA’s David Hathaway says, “Sunspot counts are at a 50-year low. We're experiencing
a deep minimum of the solar cycle.” The 11-year solar sunspot cycle is apparently not a
factor in the Earth’s weather because there is no known 11-year-cycle counterpart in
our weather.
--By Richard Koeneman, WGN Weather Center Meteorologist
