November 12: ORD

Today is November 12th. It's the 317th 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. 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 50 and the normal low is 34. I've calculated the 34-year averages at 48 and 32.

On the warm side, in 2007 (O'Hare's second warmest November 12th) the high was 66 (O'Hare's second warmest high of the date) with a low of 44. A couple of years earlier, in 2005, the high was 65 (O'Hare's third warmest high of the date) with a low of 43. The only warm low since 1978 is 48 degrees two years ago in 2010. This low is also tied with the low of 48 degrees in 1961 as O'Hare's warmest low of the date. The record high of 70 degrees was last set in 1949 at Midway. The record high of 70 degrees was previously set in 1938 at the University of Chicago and originally adjacent to Lake Michigan way back in 1902. The record warmest low of 62 degrees occurred way back in 1902, at a time when the official readings were taken adjacent to Lake Michigan. 23 of the past 34 highs (68%) were in the: 40s (14) and 50s (9). Five highs (15%) were in the warm 60s, three of them in a five year span from 2003 through 2007. Six highs (17%) were in the cold: 20s (1) and 30s (5). Our most recent 30s high was 34 degrees in 1997. O'Hare has never had a high of 70 degrees or higher on November 12th. O'Hare's warmest November 12th was in 1964 (high of 67 (O'Hare's warmest high of the date), low of 45). The other warm 11/12 was in 1961 (high of 59, low of 48 (with 2010, 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 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 cool side, in 1986 (O'Hare's coolest November 12th) the high was 30 with the record low of 8. In 1995 (O'Hare's second coolest November 12th) the high was the record coolest high of 28 with a low of 14 (O'Hare's second coldest low of the date). A year later, in 1996 (O'Hare's third coolest November 12th), the high was 30 with a low of 17. Those highs of 30 degrees are O'Hare's second coolest highs of the date. The following year of 1997 saw a high of 34 with a low of 19. In 1983 the high was 39 with a low of 19. The other cool high of 37 degrees occurred in 1991. The other cold low of 22 degrees occurred in 1984. 16 of the last 34 lows (47%) were in the 30s. 11 lows (32%) were in the cold: 0s (1), 10s (4) and 20s (6). Seven lows (21%) were in the warm 40s. There's been no 50s lows in O'Hare's history on November 12th. The other cool years were in: 1976 (high of 37, low of 15 (O'Hare's third coldest low of the date)), 1959 (high of 33, low of 22) and 1977 (high of 38, low of 23).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:11 and sunrise is at 6:41. Sunset is at 16:34 and twilight ends at 17:04. There's a total of 9 hours, 53 minutes of daylight today and 10 hours, 53 minutes between twilights. We lost three minutes of daylight from yesterday. Tomorrow twilight begins at 6:12 and sunrise is at 6:42. The moon is waning crescent, heading towards new tomorrow at 16:08. Illumination was 4% at midnight, will be 2% at noon and 1% at midnight tonight. Moonrise was at 5:05 this morning. Moonset is at 15:39 this afternoon. Moonrise is at 6:21 tomorrow morning. Moonlight time is 10 hours, 34 minutes which is 35 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 20s, 60s and 70s occur infrequently. Thanksgiving is in ten days.