Halloween Climate Data for Chicago

Halloween Weather for Northern Illinois: Statistics for Chicago and Rockford

Chicago:
The following statistics comprises 136 years of data. Data collection began at the University of Chicago, then at Midway, and currently at O'Hare which is now the official station for Chicago.

Frequency distribution of high temperatures for Chicago. This dataset shows that the most frequent range of high temperatures on Halloween is in between 50 and 59 degrees. The normal high for Halloween is 55 degrees, which falls in the range of the most frequent highs. The record high is 84 degrees set in 1950. This was the only time in Chicago’s history that the high temperature on Halloween was in the 80s. The coldest high temperature on Halloween is 31 degrees which occurred in 1873. Last year, the high temperature was 62 degrees, which is in the second most common range of high temperatures.

Frequency distribution of low temperatures for Chicago. This dataset shows that the most frequent range of low temperatures on Halloween is in between 40 and 49 degrees. The normal low for Halloween is 37 degrees, which falls in the range of the second most frequent lows. The record low is 23 which occurred in 1873. The highest low temperature for Halloween was 65 degrees in 1974. Last year, the low temperature was 41 degrees, which is in the most common range of low temperatures.

Frequency distribution of precipitation for Chicago. This dataset shows that the most frequent amount of precipitation recorded on Halloween is 0.00”, which accounts for 50% of the days in the dataset. The next most frequent range is the 0.02” to 0.25”, closely followed by a trace of precipitation. The record amount of rainfall on Halloween occurred in 1994 when 2.26” of rain fell. There have been 2 instances dating back to 1872 where an inch or more of rain fell on Halloween. Last year there was no precipitation that fell.

There have been five instances in Chicago’s history where snow has fallen on Halloween, but there has never been a measurable amount. The last time that it has snowed on Halloween was in 1993 when a Trace of snow fell.

ADDITIONAL HALLOWEEN CLIMATE DATA

MAX TEMP WARMEST	MIN TEMP WARMEST	PCPN WETTEST	SNOW
84 1950	65 1974	2.26 1994	T on many occasions
79 1944	61 1900	1.27 1941	0.0 on many occassions
78 1933, 1935	59 1933	0.75 1912
77 1968, 1974	58 1927,1950	0.65 1973
76 1888, 1915	56 1909	0.62 1935
75 1900	55 1876,1956	0.59 1987
74 1909	54 1915,1981,1997	0.55 1960
73 1876,1979,1990	53 1929,1979	0.50 1892
72 1914,1981	52 1925,1888,1882 1903,1922	0.47 1984
70 1919,1924,1953 2000	51 1924,1982	0.38 1882

MAX TEMP COLDEST	MIN TEMP COLDEST	PCPN DRIEST
31 1873	23 1873	0.00 on many occassions
32 1917	24 1917	T on many occassions
37 1878	25 1993	0.01 on many occasions
39 1874,1906,1930	26 1988,1923,1996	0.02 1873,1991
40 1913,1923,1954 1996	27 1913	0.03 1901,1972,1918
41 1875,1890,1951	28 1976,1925,1879 1890,1878	0.04 1911
42 1879,1895	30 1887,1949,1875 1874,1930	0.06 1963,1992
43 1908,1925,1939 1949	31 1954,1951.2002	0.07 1931
44 1932,1993	32 1926,1939	0.08 1959,1985
45 1898,1905	33 1906	0.09 1919,2005

Updated 10/28/2008 TJH and ACS

National Weather Service Weather Forecast Office