March 27: ORD

Today is March 27th. It's the 86th day of the year. 279 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.

According to the National Climatic Data Center (NCDC), the normal high is 50 and the normal low is 32. I've calculated the 32-year averages at 53 and 33.

On the warm side, in 1989 the high was 75 with the record warmest low of 59. In 1998 the high was 77 with a low of 56. Way back in 1910 the low was also 56. These were the former record warmest lows. In 1985 the high was 70 with a low of 54. In 1997 the high was 75 with a low of 48. In 2007 the high was 73 with a low of 45. In 1991 the high was 74 with a low of 38, a 36 degree spread. In 2003 the high was 67 with a low of 40. The record high of 82 was set back in 1945. 19 of the last 32 highs (59%) were in the: 40s (9) and 50s (10). On the warmer side, eight highs (25%) were in the: 60s (2) and 70s (6). The 60s highs occurred in the back-to-back years of 2003 (67 degrees) and 2004 (60 degrees). On the cold side, five highs (16%) 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 low of 54, a warm day. In 1975 the high was a cold 34 with a low of 31, a three degree spread. In 1974 the high was 41 with a low of 34, a seven degree spread. In 1969 the low was a cold 19 degrees. In 1968 the high was 76 with a low of 54, a warm day. In 1966 the high was 38 with a low of 20, a cold day. In 1965 the high was 32 with a low of -1, a 33 degree spread and cold day. That low of -1 was colder than the record low (see below). In 1964 the high was 36 with a low of 14, another cold day. In 1963 the high was a warm 67 with a low of 35, a 32 degree spread. In 1962 the high was a warm 62 degrees. In 1961 the high was a warm 67 with a low of 39, a warm day.

More recently, we had small spreads of six degrees in 1984 (39/33) and seven degrees in 1995 (45/38). There was a large spread of 33 degrees in 1999 (57/24).

On the cold side, in 1996 the high was 36 with the record low of 12. In 1982 the high was 36 with a low of 20. Three years before that, in 1979, the high was 39 with a low of 18. The record coldest high of 26 was set way back in 1904. 23 of the last 32 lows (72%) were in the: 20s (10) and 30s (13). Two lows (6%) were in the cold 10s (a.k.a. teens). Seven lows (22%) were in the warmer: 40s (4) and 50s (3).

Today is a major day in Chicago's snow history. In 1970 at O'Hare, this was the fourth of five days in which 11.8 inches fell. Today 0.1 inches fell.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:17 and sunrise is at 6:45. Sunset is at 19:13 and twilight ends at 19:41. There's a total of 12 hours, 28 minutes of daylight today and 13 hours, 24 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:15 and sunrise is at 6:43. The moon reached last quarter yesterday morning at 7:07 and is waning crescent. Illumination was 43% at midnight, will be 38% at noon and 33% at midnight tonight. Moonrise is at 3:06 this morning. Moonset is at 12:47 this afternoon. Moonrise is at 3:42 tomorrow morning. Moonlight time is 9 hours, 41 minutes which is 20 minutes longer than yesterday.

April Fool's Day is five days. The warm part of Spring (Warm Spring) begins in 17 days on April 13. Warm Spring runs for 52 days, through June 3. High temperatures in this period are usually in the 50s, 60s and 70s. Warmer 80s and 90s occur infrequently. -Bernie-