Information About the Gloomy Month of April 2011 for Chicago

IT WAS A GLOOMY APRIL IN CHICAGO. WITH REGARD TO
PRECIPITATION...CHICAGO-OHARE FINISHED THE MONTH WITH 4.90 INCHES OF
PRECIPITATION...WHICH IS 1.22 INCHES ABOVE NORMAL. HOWEVER...THIS
VALUE WAS NOT ALL THAT EXCEPTIONAL IN THAT IT DOES NOT EVEN RANK IN
THE TOP 20 FOR RAINIEST APRILS IN THE PERIOD OF RECORD. WHAT WAS
NOTABLE ABOUT APRIL WAS THE VERY FREQUENT OCCURRENCE OF
PRECIPITATION. AT LEAST A TRACE OF PRECIPITATION OCCURRED ON 20 OUT
OF THE 30 DAYS IN APRIL AT CHICAGO O`HARE...WITH AT LEAST 0.01
INCHES RECORDED ON 17 OUT OF THE 30 DAYS AND 13 DAYS WITH AT LEAST
0.10 OF PRECIPITATION RECORDED. THE APRIL NORMAL FOR DAYS WITH AT
LEAST 0.01 INCHES OF PRECIPITATION IS 13 AND THE NORMAL FOR DAYS
WITH AT LEAST 0.10 INCHES OF PRECIPITATION IS 7.

THE FREQUENT PRECIPITATION LED TO PERSISTENT CLOUD COVER FOR MUCH OF
THE MONTH. ACCORDING TO MIDWAY OBSERVER FRANK WACHOWSKI`S MONTHLY
RECORDS OF PERCENTAGE OF POSSIBLE SUNSHINE EXPERIENCED...APRIL 2011
WAS THE CLOUDIEST APRIL...WITH ONLY 32 PERCENT OF POSSIBLE SUNSHINE
(WITH RECORDS DATING BACK TO 1893).

DESPITE PROBABLE PUBLIC PERCEPTION THAT IT WAS ALSO UNUSUALLY COOL
IN APRIL...TEMPERATURES WERE ACTUALLY NEAR NORMAL ACROSS NORTHERN
ILLINOIS AND NORTHWEST INDIANA. AVERAGE MAXIMUM TEMPERATURES AT
CHICAGO-O`HARE WERE 1.9 DEGREES BELOW NORMAL...BUT AVERAGE MINIMUM
TEMPERATURES WERE 1.7 DEGREES ABOVE NORMAL...LEAVING THE MONTHLY
AVERAGE TEMPERATURE JUST 0.1 DEGREES BELOW THE 1971-2000 NORMAL OF 47.8.
THIS OWES TO THE PERSISTENT CLOUD COVER AND FREQUENT PRECIPITATION
THAT IN GENERAL KEPT DAYS COOLER AND NIGHTS MILDER.

RC



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