April 25: ORD

Today is April 25th. It's the 115th day of the year. 250 days remain. It's week 17 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 62 and the normal low is 41. I've calculated the 32-year averages at 65 and 42.

On the warm side, in 1990 the high was the record high of 87 with a low of 66. You are seeing double! The high and low temperatures in 1990 were the same for the 24th and the 25th. Four years later, in 1994, the high was 85 with a low of 59. In 1979 the high was 73 with a low of 61. In 1986 the high was 75 with a low of 56. Other warm highs were 82 three years ago (in 2008) and 77 two years ago (in 2009). Another warm low was 54 in 1996. The record warmest low of 68 occurred back in 1915. 20 of the last 32 highs (63%) were in the: 60s (12) and 70s (8). On the warmer side, three highs (9%) were in the 80s. On the cold side, nine highs (28%) were in the: 40s (4) and 50s (5). Our most recent 50s high was 57 in 2003.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1976 the high was a cold 45 with a low of 36, a cold day. In 1974 the high was 66 with a low of 36, a 30 degree spread. In 1972 the high was a cold 50 with a low of 31, a cold day. In 1971 the high was 68 with a low of 37, a 31 degree spread. In 1970 the high was 76 with a low of 54, a warm day. In 1969 the high was 72 with a low of 41, a 31 degree spread. In 1967 the high was 52 with a cold low of 28, a cold day. In 1966 the high was 73 with a low of 39, a 34 degree spread. In 1962 the high was 84 with a low of 56, a warm day. 1962 is also the year of the former record high of 86 at Midway. In 1961 the high was a cold 45 with a low of 40, a five degree spread.

More recently, we had a small spread of four degrees in 2007 (49/45). We had large spreads of 43 degrees in 1983 (71/28), 38 degrees in 2008 (82/44), 36 degrees in 2009 (77/41), 32 degrees in 1988 (70/38), 31 degrees in 1984 (70/39), 30 degrees in 1985 (71/41) and 30 degrees in 1999 (63/33).

On the cold side, in 1980 the high was 46 with a low of 30. In 2006 the high was 46 with a low of 32. Another cold low was 28 in 1983. Other cold highs were 47 in 1992 and 49 in 2007. That low of 28 in 1983 was the low point of a day which saw a high of 71. The record low of 27 was set way back in 1887. The record coldest high of 40 occurred back in 1910. 25 of the last 32 lows (78%) were in the: 30s (13) and 40s (12). One low was in the cold 20s. Six lows were in the warmer: 50s (4) and 60s (2).

The recent cold of April 2011: Monday, April 18: high of 41, low of 32. The second coldest April 18 of the past 33 years. Only 1983 (37/23) was colder. Tuesday, April 19: high of 38, low of 34. The second coldest April 19 of the past 33 years. Only 1983 (44/22) was colder. Wednesday, April 20: high of 43, low of 32. The second coldest April 20 of the past 33 years. Only 1981 (41/30) was colder.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:28 and sunrise was at 5:58. Sunset is at 19:46 and twilight ends at 20:16. There's a total of 13 hours, 48 minutes of daylight today and 14 hours, 48 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 5:26 and sunrise is at 5:56. The moon is waning crescent, having reached last quarter last night at 21:47. Illumination was 49% at midnight, will be 44% at noon and 39% at midnight tonight. Moonrise is at 2:13 this morning. Moonset is at 12:43 this afternoon. Moonrise is at 2:40 tomorrow morning. Moonlight time is 10 hours, 30 minutes which is 30 minutes longer than yesterday.

The warm part of Spring (Warm Spring) began 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. Administrative Professionals Day is in two days. Arbor Day is in four days. -Bernie-