Dear Tom,
I hear meteorologists use the term "clear" skies and "fair" skies. What is the difference
between the two?
—Larry Jahn, Macomb
Dear Larry,
The term "clear" skies means exactly that: a near or total absence of clouds. It is a phrase
that most meteorologists like to reserve for nighttime forecasts, preferring to use an
unqualified "sunny" on a cloudless day without the need to modify the sunshine forecast
with the usual qualifiers of "mostly" or "partly." "Fair," on the other hand, isused to
describe pleasant weather conditions. Its use implies no precipitation, limited low-cloud
sky cover, good visibilities and light winds. Many forecasters rely on a forecast of "fair"
for the hours of darkness when thin, high-level cirrus clouds are present; the stars and
planets are still visible, but the presence of these high clouds precludes the use of "clear."
