October 14: ORD

Today is October 14th. It's the 287th day of the year. 78 days remain. It's week 41 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.

According to the National Climatic Data Center (NCDC), the normal high is 63 and the normal low is 43. I've calculated the 32-year averages at 62 and 44.

On the warm side, in 1989 the high was 85 (the only 80s high of the past 32 years and just the fourth 80s high in O'Hare's history on October 14th) with a low of 52, a 33 degree spread. In 2000 the high was 74 with a low of 60. In 1984 the high was 70 with a low of 62. Those were our only 60s lows. The other warm high was our most recent 70s high, 76 in 2005. The record high of 89 was set in 1975. The record warmest low of 66 occurred way back in 1879, a time when the official readings were taken adjacent to Lake Michigan. 16 of the past 32 highs (50%) were in the 60s. Five highs (16%) were in the warm: 70s (4) and 80s (1). 11 highs (34%) were in the cool: 40s (3) and 50s (8).

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 cool 51 degrees. In 1976 the high was 70 with a low of 37, a 33 degree spread. In 1975 the high was 85 with a low of 62, a hot day. 1975 was the year of the record high of 89 at Midway. In 1973 the high was a warm 75 degrees. In 1969 the high was a cool 51 degrees. In 1968 the high was 81 with a low of 64, a warm day. In 1966 the high was 70 with a warm low of 63, a seven degree spread and warm day. In 1965 the high was 71 with a low of 39, a 32 degree spread. In 1964 the high was 70 with a low of 33, a 37 degree spread. 1963 was a dual day. The high of 77 was way warmer than normal and the low of 29 was way cooler than normal. The spread of 48 degrees was incredible. In 1962 the high was 86 with a low of 61, a hot day. In 1960 the low was a warm 58 degrees. In 1959 the high was a cool 50 degrees.

More recently, there was a large spread of 31 degrees in 1979 (62/31). The small spread was six degrees two years ago, in 2009 (48/42).

On the cool side, in 2006 the high was 50 with a low of 32. Two decades earlier, in 1986, the high was 48 with a low of 34. The other cool highs were 48 two years ago (in 2009) and 49 in 1997. The other cold lows were 30 in 2002 and 31 in 1979. The record low of 27 was set way back in 1872 and the record coolest high of 43 occurred back in 1937. Both records occurred at a time when the official readings were taken adjacent to Lake Michigan. 25 of the last 32 lows (78%) were in the: 30s (11) and 40s (14). Seven lows (22%) were in the warm: 50s (5) and 60s (2).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:36 and sunrise is at 7:05. Sunset is at 18:13 and twilight ends at 18:42. There's a total of 11 hours, 8 minutes of daylight today and 12 hours, 6 minutes between twilights. We lost four minutes of daylight from yesterday. Tomorrow twilight begins at 6:38 and sunrise is at 7:06. The moon is waning gibbous. Illumination was 96% at midnight, will be 94% at noon and 91% at midnight tonight. Moonset is at 9:37 this morning. Moonrise is at 19:23 tonight. Moonset is at 10:34 tomorrow morning. Moonlight time is 14 hours, 14 minutes which is 23 minutes longer 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 ten days.