November 5: ORD

Today is November 5th. It's the 309th 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. Before that, the official site was at various locations in Chicago going back to Monday, October 16, 1871. 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 33-year averages at 51 and 35.

On the warm side, in 1978 the high was 78 with a low of 47. Three years ago (also three decades later) in 2008 the high was 71 with a low of 47. The other warm high was 67 in 1999. The other warm low was 49 in 1994. The record high of 79 was set in 1978 at Midway. The record warmest low of 54 occurred in 1956 at Midway. 21 of the past 33 highs (64%) were in the: 40s (12) and 50s (9). Eight highs (24%) were in the warm: 60s (6) and 70s (2). Four highs (12%) were in the cold 30s. Our most recent 60s high was 62 in 2005.

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

On the cold side, in 1991 the high was 38 with a low of 17 (our only 10s low). Four years later, in 1995, the high was 37 with a low of 20. In 1984 the high was 40 with a low of 23. Two years prior, in 1982, the high was 34 with a low of 30, a four degree spread. The other cold highs were 36 in 1992, 40 last year (in 2010), 41 in 1998 and 41 in 2002. The record low of 11 and record coldest high of 30 were set on the same cold day in 1951 at Midway. 17 of the last 33 lows (52%) were in the 30s. Seven lows (21%) were in the cold: 10s (1) and 20s (6). Nine lows (27%) were in the warm 40s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 7:02 and sunrise is at 7:31. Sunset is at 17:42 and twilight ends at 18:12. There's a total of 10 hours, 11 minutes of daylight today and 11 hours, 10 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:03 and sunrise is at 6:32. The moon is waxing gibbous. Illumination was 74% at midnight, will be 78% at noon and 82% at midnight tonight. Moonset is at 2:35 this morning. Moonrise is at 15:04 this afternoon. Moonset is at 2:34 tomorrow morning. Moonlight time is 11 hours, 31 minutes which is 36 minutes longer than yesterday.

Cool Fall began November 2 and runs for 29 days through November 30. High temperatures in this period are usually in the 30s, 40s and 50s. Highs in the 10s and 20s occur infrequently. Election Day is in three days. Veterans Day is in six days. Thanksgiving is in 19 days.