March 28: ORD

Today is March 28th. It's the 88th day of the year. 278 days remain. It's week 13 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. Before this, the official site of record 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 52 and the normal low is 33. I've calculated the 33-year averages at 53 and 34.

On the warm side, in 1986 the high was the record high of 79 with a low of 43, a 36 degree spread. Three years later, in 1989, the high was 68 with a low of 54 (O'Hare's warmest low of the date). In 2004 the high was 74 with a low of 48. In 1981 the high was 78 with a low of 42, a 36 degree spread. In 1998 the high was 65 with a low of 49. The year before, in 1997, the high was 62 with a low of 48. The record warmest low of 57 occurred back in 1910, at a time when the official readings were taken adjacent to Lake Michigan. 22 of the last 33 highs (67%) were in the: 40s (11) and 50s (11). O'Hare recorded seven consecutive 40s & 50s highs from 1990 through 1996. On the warm side, eight highs (24%) were in the: 60s (5) and 70s (3). O'Hare's warmest March 28th was in 1968 as the high was 78 with a low of 52. That high of 78 was O'Hare's warmest until 1986. On the cold side, three highs (9%) were in the 30s.

In looking back through the years to the first March at O'Hare in 1959, the following instances were notable: In 1977 the high was 62 with a warm low of 50, a warm day. In 1975 the high was a cold 38 with a low of 34, a four degree spread. In 1974 the high was a cold 40 with a low of 36, a four degree spread. In 1970 the high was 30 with a low of 15, a cold day. In 1968 the high was 78 with a low of 52, a warm day. In 1966 the low was a cold 20 degrees. In 1965 the high was 39 with a low of 19, a cold day. In 1964 the high was 34 with a low of 18, another cold day. In 1962 the high was was 69 with a low of 48, a warm day. In 1960 the high was 42 with a low of 35, a seven degree spread. In 1958 the high was a cold 40 degrees.

More recently, we had small spreads of six degrees in 1995 (44/38), six degrees in 2007 (50/44), six degrees three years ago (in 2009) (38/32) and seven degrees in 1980 (44/37). There were large spreads of 31 degrees in 1979 (59/28) and 33 degrees in 2005 (60/27).

On the cold side, last year, in 2011, the high was 36 with a low of 21. In 1983 the high was 38 with a low of 26. The other cold low was 21 in 1982. The other cold highs were 38 three years ago in 2009 and 40 the year prior, in 2008. The record low of 9 and record coldest high of 23 were set on the same day way back in 1887, at a time when the official readings were taken adjacent to Lake Michigan. 26 of the last 33 lows (79%) were in the: 20s (10) and 30s (16). O'Hare recorded seven consecutive 20s & 30s lows from 1990 through 1996. Seven lows (21%) were in the warm: 40s (6) and 50s (1). O'Hare's coldest March 28th was in 1970 with a high of 30 and low of 15. The second coldest March 28th was in 1964 with a high of 34 and low of 18.  

Today is a major day in Chicago's snow history. In 1970 at O'Hare, this was the fifth of five days in which 11.8 inches fell. Today 1.0 inches fell.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:14 and sunrise is at 6:42. Sunset is at 19:15 and twilight ends at 19:43. There's a total of 12 hours, 33 minutes of daylight today and 13 hours, 29 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:12 and sunrise is at 6:40. The moon is waxing crescent and will reach first quarter in two days. Illumination was 26% at midnight, will be 31% at noon and 35% at midnight tonight. Moonset was at 0:23 this morning. Moonrise is at 9:53 this morning. Moonset is at 1:13 tomorrow morning. Moonlight time is 14 hours, 30 minutes which is 21 minutes shorter than yesterday.

Spring began on March 12th and runs for 84 days through June 3rd. Cool Spring began on March 12th and runs for 32 days through April 12th. High temperatures in this period are usually in the 30s, 40s and 50s. Highs in the 60s and 70s usually occur infrequently. April Fools' Day and Palm Sunday are in four days. Good Friday is in nine days. Easter Sunday is in 11 days.