March 16: ORD

Today is March 16th. It's the 75th day of the year. 290 days remain. It's week 11 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 46 and the normal low is 28. I've calculated the 32-year averages at 47 and 29.

On the warm side, in 2003 the high was 67 with a low of 42. In 1995 the high was 71 with a low of 37, a 34 degree spread. Two years ago, in 2009, the high was 65 with a low of 39. In 1990 the high was 62 with a low of 40. The record high of 78 and record warmest low of 49 were set on the same warm day back in 1945. 27 of the last 32 highs (84%) were in the: 30s (10), 40s (10) and 50s (7). Our most recent 40s high was 41 in 2002. On the warmer side, five highs were in the: 60s (4) and 70s (1).

In looking back through the years to the first March at O'Hare in 1959, the following instances were notable: In 1972 the high was 42 with a low of 35, a seven degree spread. In 1971 the high was a cold 32 with a low of 25, a seven degree spread. In 1969 the high was 53 with a low of 22, a 31 degree spread. In 1968 the high was a warm 63 with a low of 33, a 30 degree spread. In 1966 the high was a warm 59 degrees. In 1964 the high was a warm 66 with a low of 27, a 39 degree spread. In 1960 the high was a cold 31 with a low of 24, a seven degree spread.

More recently, we had small spreads of three degrees in 2004 (33/30), four degrees in 2001 (34/30) and six degrees in 2006 (38/32).

On the cold side, in 1997 the high was 37 with a low of 11. Three years earlier, in 1994, the high was 36 with a low of 22. Other cold highs were 33 in 2004 and 34 in 2001. The record low of -1 and record coldest high of 13 were set on the same cold day way back in 1900. 28 of the last 32 lows (88%) were in the: 20s (15) and 30s (13). Two lows were in the cold 10s (a.k.a. teens) and two lows were in the warmer 40s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:36 and sunrise is at 7:04. Sunset is at 19:01 and twilight ends at 19:29. There's a total of 11 hours, 57 minutes of daylight today and 12 hours, 53 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:34 and sunrise is at 7:02. The moon is waxing gibbous. Illumination was 83% at midnight, will be 87% at noon and 91% at midnight tonight. Moonset is at 4:54 this morning. Moonrise is at 15:35 this afternoon. Moonset is at 5:28 tomorrow morning. Moonlight time is 13 hours, 19 minutes which is 37 minutes shorter than yesterday.

St. Patrick's Day is tomorrow. The warm part of Spring (Warm Spring) begins in 28 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-