Public Information Statement
Issued by NWS Chicago, IL

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

000
NOUS43 KLOT 030117
PNSLOT
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
031330-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
817 PM CDT THU JUL 2 2015

...UNUSUALLY COOL START TO JULY IN CHICAGO...

JULY MARKS THE CLIMATOLOGICALLY WARMEST PART OF THE YEAR IN THE
MIDWEST...BUT THIS JULY HAS NOT STARTED THAT WAY. THE HIGH
TEMPERATURE ON JULY 1ST AND JULY 2ND AT CHICAGO-O`HARE WAS 69
DEGREES...15 DEGREES BELOW THE NORMAL HIGH OF 84 DEGREES. MULTIPLE
LOCATIONS IN NORTHERN ILLINOIS AWAY FROM CHICAGO EVEN OBSERVED
MORNING LOW TEMPERATURES ON JULY 2ND IN THE 40S...COMPARED TO
NORMAL LOWS FOR EARLY JULY IN THE LOWER 60S.

FOR SOME PERSPECTIVE ON THE HIGH TEMPERATURES THE PAST 2 DAYS AT
CHICAGO-O`HARE...THERE HAD ONLY BEEN 4 JULYS GOING BACK TO 1872
IN WHICH THERE WERE 2 OR MORE CONSECUTIVE DAYS WITH HIGHS LESS
THAN 70 DEGREES TO START THE MONTH IN CHICAGO. THE MOST RECENT
PRIOR TO THIS YEAR WAS IN JULY 1930. THE PREVIOUS 4 TIMES IN WHICH
THERE WERE 2 OR MORE CONSECUTIVE DAYS WITH HIGHS LESS THAN 70
DEGREES TO START JULY OCCURRED WHEN THE OFFICIAL CLIMATE SITE FOR
CHICAGO WAS NEAR THE LAKESHORE AND THUS THE COOLING INFLUENCE OF
LAKE MICHIGAN. FROM 1942 TO JANUARY 1980...THE CLIMATE SITE WAS AT
MIDWAY AIRPORT...AND SINCE JANUARY 1980...THE CLIMATE SITE HAS
BEEN AT O`HARE AIRPORT. OVERALL...SINCE 1872...JULY HAS AVERAGED
1.7 DAYS WITH HIGHS LESS THAN 70 IN CHICAGO...BUT SINCE
1942...THE AVERAGE HAS DROPPED TO 0.7 DAYS.

2+ DAYS WITH SUB-70 HIGHS TO START JULY IN CHICAGO
--------------------------------------------------
1904: JULY 1-2
1908: JULY 1-3
1924: JULY 1-4
1930: JULY 1-2
2015: JULY 1-2

$$

RC



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.