April 16: ORD

Today is April 16th. It's the 106th day of the year. 259 days remain. It's week 16 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 58 and the normal low is 38. I've calculated the 32-year averages at 60 and 39.

On the warm side, in 2002 the high was the record high of 87 with the near-record warmest low of 68. The former record high of 86 occurred in 1976 at Midway and the record warmest low of 69 occurred in 1976, also at Midway. Two years later, in 2004, the high was 82 with a low of 58. In 1982 the high was 68 with a low of 58. Other warm highs were 74 in 2005, 73 in 1989 and 73 in 2008. 14 of the last 32 highs (44%) were in the 60s. On the warmer side, five highs (16%) were in the: 70s (3) and 80s (2). On the cold side, 13 highs (40%) were in the: 40s (9) and 50s (4). Our most recent 40s high was 42 in 2001.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1978 the high was a cold 46 degrees. In 1977 the high was 83 with a low of 55, a warm day. In 1976 the high was 85 with a low of 68, a warm day and year of the record warmest low. In 1971 the high was a warm 70 degrees. In 1970 the high was 72 with a low of 52, a warm day. In 1969 the high was a warm 77 with a low of 49, a warm day. In 1968 the high was a warm 70 degrees. In 1967 the high was 74 with a low of 54, a warm day. In 1966 the high was 62 with a low of 27, a 35 degree spread. In 1964 the high was 84 with a low of 51, a 33 degree spread and warm day. In 1963 the high was 78 with a low of 53, a warm day. In 1962 the high was 48 with a cold low of 24, a cold day. In 1961 the high was a cold 33 with a low of 28, a five degree spread and cold day. In 1960 the high was 72 with a low of 51, a warm day. In 1959 the high was a warm 74 with a low of 46, a warm day.

More recently, we had a small spread of four degrees in 1999 (46/42). There were large spreads of 37 degrees in 2005 (74/37), 31 degrees in 1989 (73/42) and 30 degrees in 2007 (62/32).

On the cold side, in 1983 the high was 43 with a low of 26. In 2001 the high was 42 with a low of 29. In 1980 the high was 49 with a low of 24. Other cold highs were 43 in 1984, 43 in 1993, 45 in 1986 and 46 in 1999. The record low of 18 and record coldest high of 27 were set on the same cold day way back in 1875. 26 of the last 32 lows (81%) were in the: 30s (16) and 40s (10). Three lows were in the cold 20s. Three lows were in the warmer: 50s (2) and 60s (1).

Today is a major day in Chicago's snow history. 1961 was the year. O'Hare had 4.7 inches, the second of two days of 5.9 inches of snow. Midway had 5.4 inches, the second of three days of 6.8 inches of snow. Rockford recorded 4.4 inches.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:42 and sunrise is at 6:11. Sunset is at 19:36 and twilight ends at 20:05. There's a total of 13 hours, 25 minutes of daylight today and 14 hours, 23 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 5:41 and sunrise is at 6:10. The moon is waxing gibbous and will be full tomorrow as the full Pink (a.k.a. Sprouting Grass, Egg or Fish) moon at 21:44. "Pink" moon refers to the wild ground phlox. Illumination was 95% at midnight, will be 97% at noon and 99% at midnight tonight. Moonset is at 4:55 this morning. Moonrise is at 18:17 this afternoon. Moonset is at 5:27 tomorrow morning. Moonlight time is 10 hours, 38 minutes which is 48 minutes shorter than yesterday.

The warm part of Spring (Warm Spring) began three days ago. 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. Palm Sunday is tomorrow. Good Friday and Earth Day are in six days. -Bernie-