March 30: ORD

Today is March 30th. It's the 89th day of the year. 276 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 52 and the normal low is 32. I've calculated the 32-year averages at 54 and 35.

On the warm side, in 1998 the high was the co-record high of 79 with the record warmest low of 66. In 2005 the high was 77 with a low of 54. In 1986 the high was the co-record high of 79 with a low of 51. Four years earlier, in 1982, the high was 63 with a low of 48. In 1999 the high was 72 with a low of 38, a 34 degree spread. Two decades earlier, in 1979, the high was 66 with a low of 43. Other warm highs were 70 in 2006, 66 in 1993 and 64 last year in 2010. Another warm low was 46 in 2007. 14 of the last 32 highs (44%) were in the 40s. On the warmer side, 16 highs (50%) were in the: 50s (6), 60s (5) and 70s (5). On the cold side, two highs (6%) 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 1978 the high was 57 with a low of 27, a 30 degree spread. In 1977 the high was 65 with a low of 42, a warm day. In 1975 the high was a cold 30 with a low of 21, a cold day. In 1972 the high was a cold 37 with a low of 23, a cold day. In 1969 the high was 27 with a low of 12, a cold day, year of the record low and record coldest high. In 1968 the high was a warm 76 with a low of 34, a 42 degree spread and warm day. In 1967 the high was 79 (equal to the record high) with a low of 53, another warm day. In 1965 the high was 36 with a low of 20, a cold day. In 1964 the high was 31 with a low of 2, another cold day. That low of 2 was colder than the record low. And of course, it isn't the record because O'Hare was not the official station of record for Chicago in 1964. In 1963 the high was a warm 75 with a low of 41, a 34 degree spread and warm day. In 1961 the low was a cold 20 degrees.

More recently, we had small spreads of six degrees in 1985 (38/32) and six degrees three years ago in 2008 (42/36). There were large spreads of 32 degrees in 1993 (66/34), 35 degrees in 2006 (70/35) and 35 degrees last year in 2010 (64/29).

On the cold side, in 1987 the high was 34 with a low of 23. In 1991 the high was 42 with a low of 33. In 2003 the high was 43 with a low of 23. Another cold high was 38 in 1985. The record low of 12 and record coldest high of 27 were set on the same cold day in 1969. 17 of the last 32 lows (53%) were in the 30s. Eight lows (25%) were in the cold 20s. Seven lows (22%) were in the warmer: 40s (4), 50s (2) and 60s (1).

Today is a major day in Chicago's snow history. Today and tomorrow, back in 1926 at the University of Chicago, 8.7 inches fell. Rockford today had 2.5 of it's 16 inch total back in 1926.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:12 and sunrise is at 6:40. Sunset is at 19:17 and twilight ends at 19:45. There's a total of 12 hours, 37 minutes of daylight today and 13 hours, 33 minutes between twilights. We gained four minutes of daylight from yesterday. Tomorrow twilight begins at 6:10 and sunrise is at 6:38. The moon is waning crescent. Illumination was 16% at midnight, will be 13% at noon and 10% at midnight tonight. Moonrise is at 4:38 this morning. Moonset is at 15:52 this afternoon. Moonrise is at 5:02 tomorrow morning. Moonlight time is 11 hours, 14 minutes which is 34 minutes longer than yesterday.

April Fool's Day is two days. The warm part of Spring (Warm Spring) begins in 14 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-