November 5: ORD

Today is November 5th. It's the 310th day of the year. 56 days remain. It's week 45 of the year.
 
Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 54 and the normal low is 37. I've calculated the 34-year averages at 52 and 35.

On the warm side, in 1978 (O'Hare's second warmest November 5th) the high was 78 (O'Hare's warmest high of the date) with a low of 47. Three decades later, in 2008, the high was 71 with a low of 47. The other warm highs were 67 degrees in 1971, 67 degrees in 1999 and 66 degrees in 1965. The other warm lows were 49 degrees (O'Hare's second warmest lows of the date) in 1977 and again in 1994. The record high of 79 degrees was set in 1978 at Midway. The record warmest low of 54 degrees occurred in 1956 at Midway. 22 of the past 34 highs (65%) were in the: 40s (12) and 50s (10). O'Hare recorded six consecutive highs in the 40s and 50s from 1983 through 1988. Eight highs (23%) were in the warm: 60s (6) and 70s (2). Four highs (12%) were in the cold 30s. O'Hare's warmest November 5th was in 1975 as the high was 72 (O'Hare's second warmest high) with a low of 54 (O'Hare's warmest low of the date).

In looking back through the years to the first November at O'Hare in 1958, the following instances were notable: in 1977 the low was a warm 49 degrees. In 1976 the low was a cold 25 degrees. In 1975 the high was 72 with a low of 54, a warm day. In 1974 the high was 45 with a low of 40, a five degree spread. The same temperatures also occurred the prior day (November 4) in 1974. In 1973 the high was 36 with a low of 23, a cold day. In 1971 the high was a warm 67 degrees. In 1967 the high was a cold 35 with a low of 27, a cold day. In 1965 the high was a warm 66 with a low of 28, a 38 degree spread. In 1964 the high was 59 with a low of 29, a 30 degree spread. In 1963 the high was 53 with a low of 46, a seven degree spread. In 1961 the low was a cold 24 degrees.

More recently, there was an additional large spread of 30 degrees in 1983 (58/28). There were additional small spreads of five degrees in 1998 (41/36), six degrees in 1992 (36/30) and seven degrees in 2002 (41/34).

On the cool side, in 1991 (O'Hare's coolest November 5th) the high was 38 with a low of 17 (O'Hare's coldest low of the date and only low in the 10s (a.k.a. teens) for the date). Four years later, in 1995 (O'Hare's second coolest November 5th), the high was 37 with a low of 20 (O'Hare's second coldest low of the date). In 1984 the high was 40 with a low of 23. Two years prior, in 1982, the high was 34 (O'Hare's coolest high of the date) with a low of 30, a four degree spread. The other cold lows were 24 degrees in 1961 and 25 degrees in 1976. The other cool highs were 36 degrees in 1992, 40 degrees two years ago (in 2010), 41 degrees in 1998 and 41 degrees in 2002. The record low of 11 degrees and record coolest high of 30 degrees were set on the same cold day in 1951 at Midway. 18 of the last 34 lows (53%) were in the 30s. Seven lows (21%) were in the cold: 10s (1) and 20s (6). Nine lows (26%) were in the warm 40s. O'Hare's other cool November 5ths occurred in: 1973 (O'Hare's third coolest November 5th)(high of 36, low of 23) and 1967 (high of 35 (O'Hare's second coolest high of the date), low of 27). 

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:03 and sunrise is at 6:32. Sunset is at 16:41 and twilight ends at 17:11. There's a total of 10 hours, 9 minutes of daylight today and 11 hours, 8 minutes between twilights. We lost three minutes of daylight from yesterday. Tomorrow twilight begins at 6:04 and sunrise is at 6:33. The moon is waning gibbous, heading for last quarter tomorrow at 18:36. Illumination was 67% at midnight, will be 63% at noon and 58% at midnight tonight. Moonset is at 11:51 this morning. Moonrise is at 22:19 tonight. Moonset is at 12:24 tomorrow afternoon. Moonlight time is 13 hours, 32 minutes which is 23 minutes shorter than yesterday.

Cool Fall began on November 2nd and runs for 29 days through November 30th. High temperatures in this period are usually in the 30s, 40s and 50s. Highs in the 10s and 20s occur infrequently. Standard Time returned yesterday. Election Day is tomorrow. Veteran's Day is in six days.