January 12: ORD

Today is January 12th. It's the 12th day of the year. 354 days remain. It's week 2 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. Observations have been official at O'Hare 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 31 and the normal low is 16. I've calculated the 33-year averages at 33 and 18.

On the warm side, in 2005 the high was the record high of 62 with a low of 34. The record high of 62 was originally set way back in 1890, at a time when the official readings were taken adjacent to Lake Michigan. A year later, in 2006, the high was 57 (one of just two 50s highs in O'Hare's history for the date) with a low of 34. In 1995 the high was 47 with a low of 37 (along with a low of 37 in 1960, O'Hare's warmest lows of the date). In 2007 the high was 48 with a low of 33. In 1992 the high was 40 with a low of 34, a six degree spread. The other warm high was 44 in 1987. The other warm lows were 30 in 2004 and 29 in 2002. The record warmest low of 42 was set back in 1932 after originally being set way back in 1890; in both cases, adjacent to Lake Michigan. 28 of the past 33 highs (85%) were in the: 20s (9), 30s (11) and 40s (8). On the warm side, two highs were in the: 50s (1) and 60s (1). O'Hare's first 50s high for the date was 58 in 1960. On the cold side, three highs were in the: single digits (1) and 10s (a.k.a. teens) (2). Before 1997, O'Hare's coldest highs were 4 degrees in both 1974 and 1977.

In looking back through the years to the first January at O'Hare in 1959, the following instances were notable: in 1978 the high was a cold 18 with a low of 7, a cold day. In 1977 the high was 4 with a low of -7, a cold day. In 1975 the high was a cold 12 with a low of 5, a cold day. In 1974 the high was 4 with a low of -13, a cold day. In 1972 the high was a warm 43 degrees. In 1969 the high was 16 with a low of -5, a cold day. In 1968 the high was 26 with a low of 20, a six degree spread and (note this!) the same temperatures as the previous day! In 1967 the low was a warm 28 degrees. In 1964 the high was 23 with a low of 19, a four degree spread. In 1963 the high was 26 with a cold low of -2, a cold day. In 1961 the high was a warm 46 with a low of 26, a warm day. In 1960 the high was 58 with a low of 37, a warm day.

More recently, we had four days of small spreads. One was four degrees: 30/26 in 1996. One was six degrees: 26/20 in 2011 (last year). Two others were seven degrees: 20/13 in 1984 and 29/22 in 1991.

On the cold side, in 1997 the high was the record coldest high of 2 with a low of -7 (our most recent below zero temperature of the date). In 1985 the high was 14 with a low of -1. Three years before, in 1982, the high and low were also 14 and -1. The other cold low was -1 in 1981. The record low of -14 was set back in 1918, at a time when the official readings were taken adjacent to Lake Michigan. 20 of the last 33 lows (61%) were in the: 10s (a.k.a. teens) (9) and 20s (11). Our most recent 10s low was 11 in 1999. Seven lows (21%) were in the cold: negative single digits (4) and single digits (3). O'Hare's coldest low of the date was -13 in 1974. Six lows (18%) were in the warm 30s.

Today is a major day in O'Hare's snow history. In 1979, 2.6 inches fell. This was the second day of a 21.7 inch, seven day storm. Back in 1903 at the Auditorium Tower in Chicago, 11.3 inches fell. This was the station of record at the time.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:50 and sunrise is at 7:21. Sunset is at 16:42 and twilight ends at 17:14. There's a total of 9 hours, 21 minutes of daylight today and 10 hours, 24 minutes between twilights. We gained a minute of daylight from yesterday. Tomorrow twilight begins at 6:49 and sunrise is at 7:21. The moon is waning gibbous, having reached the full Wolf (a.k.a. Old) moon three mornings ago at 0:15. Illumination was 90% at midnight, will be 87% at noon and 83% at midnight tonight. Moonset is at 9:00 this morning. Moonrise is at 20:53 tonight. Moonset is at 9:28 tomorrow morning. Moonlight time is 11 hours, 53 minutes which is 40 minutes longer than yesterday.

Winter began December 1st and runs for 102 days through March 11th. High temperatures in this period are usually in the 20s and 30s. Highs in the 40s and 50s occur infrequently. Martin Luther King, Jr. Day is in four days.