National Weather Service United States Department of Commerce

Snow Across the Great Lakes, Central Appalachians, and Northeast; Unsettled Weather in the West

Light to moderate snow will continue into Saturday over the Great Lakes, Central Appalachians, and Northeast. This weekend into next week, a series of atmospheric rivers will bring gusty winds, periods of heavy rain, and mountain snow to northern California and the Pacific Northwest. Colder temperatures are in store for the weekend from the Great Lakes to East Coast. Read More >

July 4-6, 2012 Heat Wave:  2nd Warmest 3-Day Period for Chicago

 

To put last week’s heat wave in perspective, July 4 through 6, 2012 was officially the second warmest 3 day period in Chicago history, with an average temperature of 91.4 degrees. (Average temperatures are calculated by adding the average high temperature and the average low temperature for the period and dividing by two.)  The warmest 3 day average temperature was 91.7 for the period July 28 through July 30, 1916, mainly due to extremely warm overnight lows.  In comparison, the July, 1995 heat wave produced a 3 day average temperature of 90.2, which ties for fourth all-time. There were two other times in Chicago history when temperatures reached 100 degrees or higher for 3 straight days – August 4 through 6 of 1947, and July 3 through 5 of 1911. 1911 ties for fourth with July of 1995 at 90.2, but the 1947 3 day average came in at 87. It was not close due to cooler overnight temperatures. The third warmest 3 day period was part of the same 1916 heat wave.

 

Year
Max/Min
Max/Min
Max/Min
3 Day Average
July 28-30, 1916
99/84
96/85
102/84
91.7
July 4-6, 2012
102/79
103/79
103/82
91.4
July 27-29, 1916
100/82
99/84
96/85
91.0
July 3-5, 1911
100/77
102/78
102/82
90.2
July 13-15, 1995
104/81
100/83
98/75
90.2
 
July 6, 2012 tied with July 13, 1995 as the second warmest average daily temperature for a single day.  July 6, 2012 had a high of 103 and a low of 82 for an average of 92.5. July 13, 1995 had a high of 104, a low of 81, and also an average of 92.5. The warmest day in Chicago history was July 30, 1916. The high was 102 and the low was 84, yielding an average of 93.   

 

Date
Maximum
Minimum
Average
July 30, 1916
102
84
93
July 6, 2012
103
82
92.5
July 13, 1995
104
81
92.5