April 8: ORD

Today is April 8th. It's the 98th day of the year. 267 days remain. It's week 14 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 55 and the normal low is 35. I've calculated the 32-year averages at 52 and 35.

On the warm side, in 1991 the high was 74 with a low of 50. A decade later, in 2001, the high was 77 with a low of 45, a 32 degree spread. Two decades earlier, in 1981, the high was 68 with a low of 46. Other warm lows were the record warmest low of 52 in 1993 and 47 in 1999. The former record warmest low of 51 occurred way back in 1875. The record high of 80 was set back in 1931. 27 of the last 32 highs (84%) were in the: 40s (11), 50s (9) and 60s (7). On the warmer side, two highs were in the 70s. On the cold side, three highs were in the 30s.

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 a cold 41 degrees. In 1974 the high was a cold 39 degrees. In 1973 the high was a cold 43 with a low of 36, a seven degree spread. In 1972 the high was 35 with a low of 14, a cold day and year of the record low (see below). That low of 14 was colder than the official record low. In 1971 the high was a warm 77 with a low of 41, a 36 degree spread and warm day. In 1970 the high was a warm 72 with a low of 45, a warm day. In 1969 the high was a warm 78 with a low of 46, a 32 degree spread and warm day. In 1968 the low was a warm 47 degrees. In 1965 the high was 46 with a low of 39, a seven degree spread. In 1964 the high was a cold 40 degrees. In 1961 the high was 42 with a low of 21, a cold day. In 1960 the high was a cold 41 degrees.

More recently, we had small spreads of five degrees three years ago in 2008 (45/40), six degrees in 2002 (52/46) and seven degrees in 1993 (59/52). The large spreads were 30 degrees in both 1988 (66/36) and 1990 (61/31).

On the cold side, in 1997 the high was 33 with a low of 24. A year earlier, in 1996, the high was 40 with a low of 21. In 1982 the high was 35 with a low of 26. In 2003 the high was the record coldest high of 32 with a low of 31, a single degree spread. In 1985 the high was 40 with a low of 25. The record coldest high of 32 first occurred in 1914. The record low of 20 was set in 1972. Other cold highs were 40 in 2007, 40 last year (in 2010), 41 in 2000 and 43 in 2006. 23 of the last 32 lows (72%) were in the: 20s (11) and 30s (12). Nine lows (28%) were in the warmer: 40s (7) and 50s (2).

Today is a major day in Chicago's snow history. In 1938, the city recorded 4.5 inches of snow. This was the last day of snow for April 1938, giving the month a total of 13.6 inches, the snowiest April in Chicago's history.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:56 and sunrise is at 6:24. Sunset is at 19:27 and twilight ends at 19:55. There's a total of 13 hours, 3 minutes of daylight today and 13 hours, 59 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 5:54 and sunrise is at 6:23. The moon is waxing crescent. Illumination was 19% at midnight, will be 23% at noon and 27% at midnight tonight. Moonrise is at 9:04 this morning. Moonset is at 0:42 early tomorrow morning. Moonrise is at 9:58 a bit later tomorrow morning. Moonlight time is 14 hours, 56 minutes which is 34 minutes shorter than yesterday.

The warm part of Spring (Warm Spring) begins in five 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. Palm Sunday is in nine days. -Bernie-