May 25: ORD

Today is May 25th. It's the 145th day of the year. 220 days remain. It's week 21 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 73 and the normal low is 51. I've calculated the 32-year averages at 69 and 49.

On the warm side, last year (2010) the high was 88 with a low of 69. Four years earlier, in 2006, the high was 75 with a low of 64. Another warm high was 84 in 1985. The record high of 94 was set back in 1911 and the record warmest low of 72 occurred back in 1914. 21 of the past 32 highs (66%) were in the: 60s (11) and 70s (10). Four highs (12%) were in the warmer 80s. Seven highs (22%) were in the cool 50s.

In looking back through the years to the first May at O'Hare in 1959, the following instances were notable: In 1978, the high was 82 with a low of 52, a 30 degree spread. In 1977 the high was a hot 90 with a low of 62, a hot day. In 1975 the low was a warm 66 degrees. In 1972 the high was a warm 85 degrees. In 1971 the high was a cool 60 degrees. In 1967 the high was 84 with a low of 49, a 35 degree spread. In 1965 the high was 82 with a warm low of 67, a warm day. In 1964 the high was 80 with a low of 48, a 32 degree spread. In 1961 the low was a cold 39 degrees.

More recently, there was a small spread of seven degrees in 1990 (60/53). There were large spreads of 34 degrees in 1985 (84/50), 34 degrees three years ago (in 2008) (78/44), 31 degrees in 1981 (80/49) and 30 degrees in 1980 (82/52).

On the cool side, in 1992 the high was 51 with the record low of 32. In 1988 the high was 59 with a low of 37. In 1983 the high was 59 with a low of 38. In 2002 the high was 57 with a low of 41. In 1997 the high was 54 with a low of 45. In 1996 the high was 56 with a low of 45. Other cool highs were 59 in 2001 and 60 in 1990. The record coolest high of 44 occurred way back in 1893. 27 of the last 32 lows (84%) were in the: 40s (13) and 50s (14). Three lows were in the cold 30s and two lows were in the warmer 60s. The 30s lows occurred between 1983 and 1992 while the 60s lows occurred between 2006 and 2010.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:51 and sunrise is at 5:24. Sunset is at 20:17 and twilight ends at 20:50. There's a total of 14 hours, 53 minutes of daylight today and 15 hours, 59 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 4:50 and sunrise is at 5:23. The moon is waning crescent, having reached last quarter yesterday at 13:52. Illumination was 46% at midnight, will be 41% at noon and 36% at midnight tonight. Moonrise is at 1:31 this morning. Moonset is at 13:34 this afternoon. Moonrise is at 1:54 tomorrow morning. Moonlight time is 12 hours, 3 minutes which is 36 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. Memorial Day is in five days.

Today, in 1979, was the most tragic day in O'Hare's history. 271 people lost their lives when an American Airlines DC 10-10, flight 191, crashed shortly after taking off from runway 32R just after 3:00 P.M. One of the three engines, number one (attached to the left wing), separated and flipped over the wing and onto the runway as the aircraft was gaining speed for takeoff. The aircraft climbed to about 300 feet, rolled to the left and then nosedived and crashed adjacent to a mobile home park. Additionally, two people on the ground were killed, two suffered severe burns and three sustained injuries from falling aircraft debris. Improper maintenance caused the engine to detach from the left wing. Today marks the 32nd anniversary of the crash. -Bernie-