April 15: ORD

Today is April 15th. It's the 105th day of the year. 260 days remain. It's week 15 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 37. I've calculated the 31-year averages at 59 and 40.

On the warm side, in 2002 the high was the record high of 88 with a low of 62. A year later, in 2003, the high was the record-challenging high of 86 with a low of 64. A year after that, in 2004, the high was 75 with a low of 46. The former record high of 84 occurred at Midway in 1976. Other warm highs were 73 in 1982 and 72 in 2000. Another warm low was 49 in 2006. The record warmest low of 67 occurred at Midway in 1976. 20 of the last 31 highs were: 50s (11) and 60s (9). On the warmer side, five highs were: 70s (3) and 80s (2). On the colder side, six highs were in the 40s.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1977 the high was 79 with a low of 49, a 30 degree spread and warm day. In 1976 the high was 82 with a low of 65, a warm day and year of the record warmest low. In 1973 the high was a warm 75 with a low of 44, a 31 degree spread and warm day. In 1971 the high was a warm 71 with a low of 35, a 36 degree spread. In 1969 the high was 61 with a low of 55, a six degree spread. In 1967 the high was 73 with a low of 54, a warm day. In 1964 the high was 62 with a low of 30, a 32 degree spread. In 1963 the high was a warm 73 with a low of 32, a 41 degree spread. In 1962 the high was 42 with a low of 28, a cold day. In 1960 the high was 72 with a low of 49, a warm day. In 1959 the high was a warm 71 with a low of 41, a 30 degree spread.

More recently, we had small spreads of five degrees in 1984 (42/37) and six degrees in 1993 (47/41). There were large spreads of 30 degrees in 2005 (63/33), 32 degrees in 1982 (73/41), 32 degrees in 2000 (72/40) and 35 degrees in 1997 (66/31).

On the cold side, in 1983 the high was 40 with a low of 29. Three years later, in 1986, the high was 40 with a low of 31. Other cold highs were 42 in 1984, 45 in 1980 and 45 in 1996. The record low of 25 was set back in 1943 and the record coldest high of 34 was set back in 1928. 27 of the last 31 lows were: 30s (15) and 40s (12). Two lows were in the colder 20s and two lows were in the warmer 60s. No lows have been in the 50s.

Today is a major day in Chicago's snow history. 1961 was the year. O'Hare had 1.2 inches, the first of two days of 5.9 inches of snow. Midway had 1.1 inches, the first of three days of 6.8 inches of snow. Rockford didn't record any snow today, but stay tuned tomorrow!

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:44 and sunrise was at 6:13. Sunset is at 19:35 and twilight ends at 20:04. There's a total of 13 hours, 22 minutes of daylight today and 14 hours, 20 minutes between twilights. Tomorrow twilight begins at 5:42 and sunrise is at 6:11. The moon is was new yesterday as of 7:29 and is waxing crescent. Illumination was 1% at midnight, will be 2% at noon and 3% at midnight tonight. Moonrise was at 6:22 this morning. Moonset is at 21:19. Moonrise is at 6:57 tomorrow morning. Moonlight time is 14 hours, 57 minutes which is 37 minutes longer than yesterday.

A niece of mine, Sara, celebrates a birthday tomorrow. - Bernie -