November 22: ORD

Today is November 22nd. It's the 326th day of the year. 39 days remain. It's week 47 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 45 and the normal low is 30. I've calculated the 33-year averages at 47 and 29.

On the warm side, in 1999 the high was 62 with a low of 46. Last year, in 2010, the high was 67 (O'Hare's warmest ever) with a low of 39. In 2003 the high was 61 with a low of 44. In 1979 the high was 59 with a low of 40. In 1998 the high was 59 with a low of 38. The other warm highs were 59 in 1983, 57 in 2001 and 57 two years ago in 2009. The record high of 69 was set back in 1913. The record warmest low of 51 occurred in 1931. Both records were set at a time when the official readings were taken adjacent to Lake Michigan. 16 of the past 33 highs (48%) were in the: 30s (9) and 40s (7). 13 highs (39%) were in the 50s. Three highs were in the warm 60s. There were two other 60s, pre-1978 (61 in 1963 & 61 in 1973). One high was in the cold 20s. The most recent 40s high was 48 in 2004. Highs from 2005 through 2009 were in the 30s and 50s.

In looking back through the years to the first November at O'Hare in 1958, the following instances were notable: in 1973 the high was a warm 61 degrees. In 1971 the low was a cold 17 degrees. In 1970 the high was 50 with a cold low of 14, a 36 degree spread. A cold front came through in 1970, as on the morning of the 23rd, the low was 10 degrees. This was a 45 degree drop. In 1967 the high was 38 with a low of 32, a six degree spread. In 1966 the high was 59 with a low of 49, a warm day. In 1964 the high was 30 with a low of 6, a cold day. In 1963 the high was a warm 61 with a low of 38, a warm day. In 1963 a cold front came through, dropping the temperature 43 degrees to a low of 18 on the 24th. In 1959 the high was a warm 59 with a low of 39, a warm day.

More recently, there were no large spreads. There was a small spread of four degrees in 1992 (43/39).

On the cold side, in 1981 the high was 26 (the only 20s high in O'Hare's history) with a low of 13. In 2000 the high was 30 with a low of 14. The other cold low was 17 in 2008. The other cold highs were 32 in 1989 and 33 in 2007. The record low of 4 was set way back in 1880. The record coldest high of 21 occurred back in 1929. Both records were set at a time when the official readings were taken adjacent to Lake Michigan. 26 of the last 33 lows (79%) were in the: 20s (13) and 30s (13). There were 13 consecutive 20s & 30s lows from 1982 through 1994. Four lows were in the cold 10s (a.k.a. teens). Three lows were in the warm 40s, most recently 44 in 2003.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:21 and sunrise is at 6:52. Sunset is at 16:26 and twilight ends at 16:57. There's a total of 9 hours, 34 minutes of daylight today and 10 hours, 36 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:22 and sunrise is at 6:53. The moon is waning crescent. Illumination was 13% at midnight, will be 9% at noon and 6% at midnight tonight. Moonrise is at 3:40 this morning. Moonset is at 14:27 this afternoon. Moonrise is at 4:57 tomorrow morning. Moonlight time is 10 hours, 47 minutes which is 40 minutes shorter 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. Thanksgiving is in two days.