January 16: ORD

Today is January 16th. It's the 16th day of the year. 350 days remain. It's week 3 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 31 and 14.

On the warm side, in 1980 the high was 56 with a low of 42. The record warmest low is 42, set back in 1913. Since the official station in 1980 was Midway and not O'Hare, this low of 42 in 1980 is not considered the official record warmest low. It actually missed being the record by a single day! A decade later, in 1990, the high was the record high of 57 with a low of 36. A couple of years earlier, in 1988, the high was 46 with a low of 32. In 2006 the high was 47 with a low of 30. The other warm highs were 50 in 1986, 43 in 1996 and 42 in 1989. The other warm lows were 31 in 1995, 26 in 1998 and 26 in 2001. 25 of the past 33 highs (76%) were in the: 20s (11), 30s (8) and 40s (6). Our most recent 30s high was 33 in 2002. On the warm side, three highs were in the 50s. O'Hare's only other 50s high of the date was 50 in 1973. On the cold side, five highs were in the: single digits (2) and 10s (a.k.a. teens) (3). O'Hare's coldest high of the date was -4 in 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 16 with a low of 8, a cold day. In 1977 the high was -4 with a low of -17, a cold day. The record coldest high of -7 was set this year (in 1977). It's unusual that Midway had a lower reading than O'Hare. In 1974 the high was 42 with a warm low of 31, a warm day. In 1973 the high was 50 with a low of 33, a warm day. In 1972 the high was 15 with a low of -13, a cold day. In 1969 the high was 37 with a warm low of 34, a three degree spread and warm day. In 1966 the high was 23 with a cold low of 1. In 1965 the high was 20 with a low of 0, a cold day. In 1963 the high was 17 with a low of -12, a cold day. In 1962 the high was 14 with a low of 0, a cold day. In 1961 the high was 31 with a low of 27, a four degree spread. In 1959 the high was 12 with a low of 1, a cold day.

More recently, we had small spreads of four degrees in 1998 (30/26), four degrees two years ago, in 2010 (27/23), five degrees in 1995 (36/31), five degrees in 2001 (31/26) and five degrees in 2004 (29/24). The large spread of 32 degrees occurred in 1986 (50/18).

On the cold side, in 1982 the high was 8 with the record low of -25, a 33 degree spread. Other lows in 1982 were as follows: Rockford: -24, DeKalb and Marengo: -17, Midway, Elgin and Barrington: -16, Wheaton: -15. Three years ago, in 2009, the high was 3 with a low of -18. In 1994 the high was 10 with a low of -16. A decade earlier, in 1984, the high was 18 with a low of -6. In 1992 the high was 27 with a low of -12, a 39 degree spread. In 2005 the high was 14 with a low of 3. In 1979 the high was 24 with a low of -7, a 31 degree spread. A couple of locations in 1979 were a lot colder than Midway's -7. They were -24 at Elgin and -21 at Rockford. In 1997 the high was 22 with a low of -4. The record coldest high of -7 was set in 1977 at Midway. 12 of the last 33 lows (36%) were in the 20s. 16 lows (49%) were in the cold: negative 20s (1), negative 10s (3), negative single digits (3), single digits (4) and 10s (a.k.a. teens) (5). O'Hare's pre-1979 cold lows for the date were -17 in 1977, -13 in 1972 and -12 in 1963. Five lows (15%) were warm: 30s (4) and 40s (1). Through Winter 2010-11, this is the average twelfth coldest day of the year.

There were two instances of back-to-back years in which temperatures were just about as opposite as they can be. In the first instance, in 1979 the high was 24 with a low of -7, overall 15.5 degrees BELOW normal. Then in 1980 the high was 56 with a low of 42, overall 25 degrees ABOVE normal. In the second instance, in 2005 the high was 14 with a low of 3, overall 15.5 degrees BELOW normal. Then in 2006 the high was 47 with a low of 30, overall 14.5 degrees ABOVE normal.

Today is a major day in O'Hare's snow history. In 1979, 0.2 inches fell. This was the sixth day of a 21.7 inch, seven day stretch of snow. This storm changed Chicago politics. The slow response that the city had to cleaning up after the storm was blamed on Mayor Michael Bilandic and his administration. This caused him to lose in the primary election to the eventual new mayor, Jayne Byrne. At O'Hare on the 13th, 15.3 inches fell while at Midway, 16.5 inches fell. This blizzard closed down the city for several days.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:48 and sunrise is at 7:19. Sunset is at 16:47 and twilight ends at 17:18. There's a total of 9 hours, 28 minutes of daylight today and 10 hours, 30 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 6:48 and sunrise is at 7:19. The moon reaches last quarter today at 3:08. Illumination was 52% at midnight, will be 46% at noon and 40% at midnight tonight. Moonrise was at 0:25 this morning. Moonset is at 11:02 this morning. Moonrise is at 1:37 tomorrow morning. Moonlight time is 10 hours, 37 minutes which is nine 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 today. National Freedom Day is in 16 days. Groundhog Day is in 17 days.