October 22: ORD

Today is October 22nd. It's the 295th day of the year. 70 days remain. It's week 43 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 60 and the normal low is 41. I've calculated the 32-year averages at 60 and 39.

On the warm side, in 1991 the high was 76 with a low of 50, our most recent 50s low. Five years prior, in 1986, the high was 75 with a low of 50. The other warm highs were 76 in 1979, 73 in 1992 and 72 in 1994 (our most recent 70s high). The record high of 87 was set in 1953 at Midway. The record warmest low of 66 occurred back in 1920, a time when the official readings were taken adjacent to Lake Michigan. 24 of the past 32 highs (75%) were in the: 50s (14) and 60s (10). A long, eight year stretch of years from 1998 through 2005 had highs in the 50s & 60s. Five highs were in the warm 70s. Three highs were in the cold 40s. The 70s highs, as noted above, occurred from 1979 to 1994. The most recent three occurred in a four year period from 1991 to 1994. Only two 80s highs occurred at O'Hare on this date, both before 1979 (see next section).

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1978 the high was a warm 73 with a low of 52, a warm day. In 1976 the high was 47 with a low of 25, a cold day. In 1975 the high was a warm 80 with a low of 46, a warm day. In 1973 the high was 71 with a low of 39, a 32 degree spread. In 1971 the high was 71 with a warm low of 59, a warm day. In 1969 the high was a cold 43 with a low of 31, a cold day. In 1967 the high was a warm 72 with a low of 35, a 37 degree spread. In 1964 the low was a cold 28 degrees. In 1963 the high was 84 (O'Hare's warmest) with a low of 59, a warm day.

More recently, there were large spreads of 33 degrees in 1989 (64/31), 31 degrees in 1979 (76/45), 31 degrees in 1992 (73/42) and 31 degrees last year, in 2010 (64/33). There was a small spread of six degrees in 1983 (55/49).

On the cold side, in 1982 the high was 49 with the record low of 22. In 1997 the high was 44 with a low of 29, our most recent 20s low. The record coldest high of 41 occurred back in 1913, a time when the official readings were taken adjacent to Lake Michigan. 28 of the last 32 lows (88%) were in the: 30s (15) and 40s (13). For 13 years, ongoing, from 1998 through 2010, lows were in the 30s & 40s. Two lows were in the cold 20s. Two more 20s lows occurred prior to 1979 on this date. Two lows were in the warm 50s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:45 and sunrise is at 7:14. Sunset is at 18:01 and twilight ends at 18:30. There's a total of 10 hours, 47 minutes of daylight today and 11 hours, 45 minutes between twilights. We lost three minutes of daylight from yesterday. Tomorrow twilight begins at 6:47 and sunrise is at 7:15. The moon is waning crescent. Illumination was 28% at midnight, will be 23% at noon and 18% at midnight tonight. Moonrise is at 2:06 this morning. Moonset is at 15:23 this afternoon. Moonrise is at 3:19 tomorrow morning. Moonlight time is 13 hours, 17 minutes which is 39 minutes shorter than yesterday.

Warm Fall began September 22 and runs for 41 days through November 1. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. United Nations Day is in two days.