January 9: ORD

Today is January 9th. It's the 9th day of the year. 357 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 17. I've calculated the 33-year averages at 29 and 16.

On the warm side, in 2002 the high was 55 (O'Hare's only 50s high) with a low of 38, our most recent 30s low. Two years prior, in 2000, the high was 41 with a low of 37, a four degree spread. A decade earlier, in 1990, the high was 42 with a low of 34. Two years later, in 1992, the high was 44 with a low of 32. In 2003 the high was 45 with a low of 28. Three years later, in 2006, the high was 38 with a low of 33, a five degree spread. The other warm high was 43 in 1983. The other warm low was 30 in 2008. The record high of 60 was set way back in 1880 and the record warmest low of 45 was set in 1939. Both records were set at a time when the official readings were taken adjacent to Lake Michigan. 21 of the past 33 highs (64%) were in the: 20s (11) and 30s (10). There were consecutive highs in the 20s & 30s as: six years from 1993 through 1998 and eight years from 2004 through 2011. On the warm side, six highs (18%) were in the: 40s (5) and 50s (1). On the cold side, six highs (18%) were in the: single digits (2) and 10s (a.k.a. teens) (4). O'Hare's coldest high was -1 in 1962.

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 3 with a low of -5, a cold day. In 1977 the high was 19 with a low of 0, a cold day. In 1976 the high was 11 with a low of 0, a cold day. In 1975 the high was 42 with a warm low of 33, a warm day. In 1973 the high was 13 with a low of 3, a cold day. In 1972 the high was 44 with a low of 35, a warm day. In 1970 the high was 15 with a low of -1, a cold day. In 1969 the low was a cold 2 degrees. In 1966 the high was a warm 43 degrees. In 1963 the high was 40 with a warm low of 33, a seven degree spread and warm day. In 1962 the high was -1 with a low of -13, a cold day and year of the record coldest high of 0 at Midway. In 1959 the high was a cold 19 degrees.

More recently, we had a small spreads of four degrees in 1997 (28/24) and seven degrees in 1993 (28/21). Except for 1994 (see next section) there were no other large spreads of 30 degrees or more.

On the cold side, in 1982 the high was 7 with a low of -19, O'Hare's coldest low. Six years later, in 1988, the high was 7 with a low of -8. In 1999 the high was 12 with a low of -4. Two decades earlier, in 1979, the high was 16 with a low of -3. Fifteen years later, in 1994, the high was 24 with a low of -7, a 31 degree spread. In 1981 the high was 19 with a low of 5. The other cold high was 19 in 1980. The record low of -20 was set way back in 1875, at a time when the official readings were taken adjacent to Lake Michigan. The record coldest high of 0 was set in 1962 at Midway. 17 of the last 33 lows (52%) were in the: 10s (9) and 20s (8). Ten lows (30%) were in the cold: negative 10s (a.k.a. negative teens) (1), negative single digits (4) and single digits (5). Six lows (18%) were in the warm 30s. Until 1982, O'Hare's coldest low was -13 in 1962. Through Winter 2010-11, this is the average fifteenth coldest day of the year.

There was an instance of back-to-back years in which temperatures were just about as opposite as they can be. In the first instance, in 1988 the high was 12 with a low of -4, overall 20 degrees BELOW normal. Then in 1989 the high was 41 with a low of 37, overall 15 degrees ABOVE normal.

Today is a major snow day in northern Illinois. Back in 1930 at Rockford, 10 inches of snow accumulated.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:50 and sunrise is at 7:22 (the latest sunrise of the year). Sunset is at 16:39 and twilight ends at 17:11. There's a total of 9 hours, 17 minutes of daylight today and 10 hours, 21 minutes between twilights. We gained a minute of daylight from yesterday. Tomorrow twilight begins at 6:50 and sunrise is at 7:21. The moon reaches the full Wolf (a.k.a. Old) moon this morning at 0:15. Illumination was 100% at midnight, will be 100% at noon and 99% at midnight tonight. Moonset was at 7:21 this morning. Moonrise was at 17:27 this afternoon. Moonset is at 7:57 tomorrow morning. Moonlight time is 10 hours, 6 minutes which is 24 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 seven days.