March 11: ORD

Today is March 11th. It's the 70th day of the year. 295 days remain. It's week 10 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 44 and the normal low is 27. I've calculated the 32-year averages at 43 and 25.

On the warm side, in 1990 the high was the record high of 74 with a low of 42, a 32 degree spread. In 2006 the high was 67 with a low of 43. Last year, in 2010, the high was 60 with a low of 44. In 1995 the high was 62 with a low of 40. Other warm highs were 60 in 1988 and 59 a year later in 1989. The record warmest low of 55 occurred way back in 1902. 20 of the last 32 highs (63%) were in the: 30s (10) and 40s (10) . On the warmer side, eight highs (25%) were in the: 50s (3), 60s (4) and 70s (1). On the cold side, four highs (12%) were in the 20s.

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 39 with a low of 33, a six degree spread. In 1977 the high was 68 with a low of 50, a warm day. In 1975 the high was 35 with a low of 28, a seven degree spread. In 1974 the high was 41 with a low of 36, a five degree spread. In 1973 the high was 65 with a low of 44, a warm day. In 1972 the high was a warm 70 with a low of 33, a spread of 37 degrees and a warm day. In 1969 the high was 31 with a low of 11, a cold day. In 1967 the high was 39 with a low of 33, a six degree spread. In 1966 the high was 57 with a low of 46, a warm day. In 1965 the high was a cold 32 degrees. In 1963 the high was 36 with a low of 29, a seven degree spread. In 1962 the high was 39 with a low of 32, a seven degree spread. In 1960 the high was a cold 25 with a low of 20, a five degree spread and cold day.

More recently, we had no other small or large spreads.

On the cold side, in 1979 the high was 27 with a low of 4. In 1998 the high was 22 with a low of 13. In 1984 the high was 25 with a low of 12. In 1992 the high was 29 with a low of 11. In 1980 the high was 31 with a low of 13. Another cold high was 31 in 1993. The record low of 3 was set at Midway in 1979. The record coldest high of 20 occurred in 1948. 15 of the last 32 lows (47%) were in the 20s. On the cold side, eight lows (25%) were in the: single digits (1) and 10s (a.k.a. teens) (7). On the warmer side, nine lows (28%) were in the: 30s (5) and 40s (4).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:45 and sunrise is at 6:12. Sunset is at 17:55 and twilight ends at 18:23. There's a total of 11 hours, 43 minutes of daylight today and 12 hours, 38 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 5:43 and sunrise is at 6:11. The moon is waxing crescent and will reach first quarter tomorrow at 17:45. Illumination was 33% at midnight, will be 38% at noon and 43% at midnight tonight. Moonrise is at 9:18 this morning. Moonset is at 0:54 early tomorrow morning. Moonrise is at 10:07 tomorrow morning. Moonlight time is 14 hours, 42 minutes which is 39 minutes shorter than yesterday.

St. Patrick's Day is in six days. The cool part of Spring (Cool Spring) begins tomorrow. Cool Spring runs for 32 days, through April 12. High temperatures in this period are usually in the 30s, 40s and 50s. Warmer 60s and 70s occur infrequently. -Bernie-