November 12: ORD

Today is November 12th. It's the 316th day of the year. 49 days remain. It's week 46 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 50 and the normal low is 34. I've calculated the 33-year averages at 48 and 32.

On the warm side, in 2007 the high was 66 with a low of 44. A couple of years earlier, in 2005, the high was 65 with a low of 43. The only warm low was 48 last year, in 2010. The record high of 70 was last set in 1949 at Midway. The record high of 70 was set previously in 1938 and originally in 1902. The record warmest low of 62 was set way back in 1902. 23 of the past 33 highs (70%) were in the: 40s (14) and 50s (9). Four highs (12%) were in the warm 60s, three of them from 2003 through 2007. Six highs (18%) were in the cold: 20s (1) and 30s (5). Our most recent 30s high was 34 in 1997. O'Hare has never had a high of 70 or more on November 12.

In looking back through the years to the first November at O'Hare in 1958, the following instances were notable: in 1977 the high was a cold 38 with a low of 23, a cold day. In 1976 the high was 37 with a low of 15, a cold day. In 1972 the high was 46 with a low of 41, a five degree spread. In 1964 the high was a warm 67 with a low of 45, a warm day. In 1961 the high was 59 with a warm low of 48, a warm day. In 1959 the high was 33 with a low of 22, a cold day.

More recently, the lone large spread was 35 degrees in 1982 (60/25). The small spreads were three degrees in 1978 (47/44), four degrees in 1991 (37/33), seven degrees in 2000 (48/41) and seven degrees in 2002 (43/36).

On the cold side, in 1986 the high was 30 with the record low of 8. In 1995 the high was the record coldest high of 28 with a low of 14. A year later, in 1996, the high was 30 with a low of 17. A year after that, in 1997, the high was 34 with a low of 19, our most recent 10s low. That's back to back to back lows in the 10s (a.k.a. teens)! In 1983 the high was 39 with a low of 19. The other cold high was 37 in 1991. The other cold low was 22 in 1984. 15 of the last 33 lows (46%) were in the 30s. 11 lows (33%) were in the cold: 0s (1), 10s (4) and 20s (6). Just one more 10s low prior to 1978: 15 in 1976. Seven lows (21%) were in the warm 40s. There's been no 50s lows in O'Hare's history on November 12. The coldest years stand out as 3 of 4 years from 1983 through 1986 and three straight years from 1995 through 1997.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:10 and sunrise is at 6:40. Sunset is at 16:35 and twilight ends at 17:05. There's a total of 9 hours, 55 minutes of daylight today and 10 hours, 55 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:11 and sunrise is at 6:41. The moon is waning gibbous, having passed full two days ago at 14:16 as the full Beaver (aka Frost) moon. Illumination was 98% at midnight, will be 97% at noon and 95% at midnight tonight. Moonset is at 8:24 this morning. Moonrise is at 17:49 this afternoon. Moonset is at 9:16 tomorrow morning. Moonlight time is 14 hours, 35 minutes which is 9 minutes longer than yesterday and shares tomorrow at it's peak time.

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 12 days.