January 14: ORD

Today is January 14th. It's the 14th day of the year. 352 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 29 and 15.

On the warm side, in 1987 the high was 45 with a low of 30. In 1996 the high was 47 (O'Hare's warmest of the date) with a low of 28. Six years earlier, in 1990, the high was 45 with a low of 29. Five years later, in 1995, the high was 39 with a low of 35 (O'Hare's warmest low of the date), a four degree spread. Two years ago, in 2010, the high was 40 with a low of 31. The other warm lows were 32 in 2001, 30 in 2002, 30 in 2007 and 28 in 2006. The record high of 60 was set back in 1928, at a time when the official readings were taken adjacent to Lake Michigan. The record warmest low of 41 was set in 1953 at Midway. 22 of the past 33 highs (67%) were in the: 20s (12) and 30s (10). On the warm side, six highs (18%) were in the 40s. On the cold side, five highs (15%) were in the: single digits (2) and 10s (a.k.a. teens) (3). O'Hare's coldest high prior to 1979 was 7 in 1963.

In looking back through the years to the first January at O'Hare in 1959, the following instances were notable: In 1975 the high was 20 with a cold low of 2, a cold day. In 1972 the high was 14 with a low of -10, a cold day. In 1970 the high was 25 with a low of 21, a four degree spread. In 1969 the high was 27 with a low of 23, a four degree spread. In 1968 the high was 35 with a warm low of 31, a four degree spread. In 1965 the high was 15 with a low of -7, a cold day. In 1963 the high was 7 with a low of -12, a cold day. In 1962 the high was 33 with a warm low of 28, a five degree spread. In 1960 the high was 38 with a warm low of 34, a four degree spread and warm day. In 1959 the high was 41 with a warm low of 32, a warm day.

More recently, we had small spreads of three degrees in 2007 (33/30), four degrees in 1999 (20/16) and four degrees in 2001 (36/32). In 1985 the spread was a large 30 degrees (33/3).

On the cold side, in 1994 the high was the record coldest high of 1 with a low of -10. The former record coldest high of 2 occurred way back in 1905. In 1982 the high was 9 with a low of -10. Three years earlier, in 1979, the high was 21 with a low of -12 (with -12 in 1963, O'Hare's coldest of the date), a large 33 degree spread. The record low of -14 was set this same year (1979) at Midway. Usually the low at O'Hare would be colder than at Midway, so this is a bit unusual. Three years ago, in 2009, the high was 14 with a low of -2. In 1997 the high was 20 with a low of -3. In 2005 the high was 15 with a low of 4 (O'Hare's most recent single digit low of the date). In 1988 the high was 21 with a low of 0. The other cold low was 3 in 1985. The other cold high was 19 in 2003. 28 of the last 33 lows (85%) were in the: single digits (6), 10s (a.k.a. teens) (8), 20s (8) and 30s (6). Five lows were in the cold: negative 10s (a.k.a. negative teens) (3) and negative single digits (2). Before 1979, the negative 10s lows were -12 in 1963 and -10 in 1972. Through Winter 2010-11, this is the average tenth coldest day of the year.

There were four instances of back-to-back years in which temperatures were just about as opposite as they can be. In the first instance, in 1987 the high was 45 with a low of 30, overall 13.5 degrees ABOVE normal. Then in 1988 the high was 21 with a low 0, overall 13.5 degrees BELOW normal. In the second instance, in 1994 the high was 1 with a low of -10, overall 28.5 degrees BELOW normal. Then in 1995 the high was 39 with a low of 35, overall 13 degrees ABOVE normal. In the third instance, in 1996 the high was 47 with a low of 28, overall 13.5 degrees ABOVE normal. Then in 1997 the high was 20 with a low of -3, overall 15.5 degrees BELOW normal. In the fourth instance, in 2009 the high was 14 with a low of -2, overall 18 degrees BELOW normal. Then in 2010, the high was 40 with a low of 31, overall 11.5 degrees ABOVE normal.

Today is a major day in O'Hare's snow history. In 1979, 0.6 inches fell. This was the fourth day of a 21.7 inch, seven day stretch of snow.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:49 and sunrise is at 7:20. Sunset is at 16:45 and twilight ends at 17:16. There's a total of 9 hours, 25 minutes of daylight today and 10 hours, 27 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 6:49 and sunrise is at 7:20. The moon is waning gibbous. Illumination was 73% at midnight, will be 68% at noon and 63% at midnight tonight. Moonset is at 9:57 this morning. Moonrise is at 23:13 tonight. Moonset is at 10:28 tomorrow morning. Moonlight time is 13 hours, 16 minutes which is 41 minutes longer than yesterday. Moonlight time is at it's peak today.

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 two days.