April 18: ORD

Today is April 18th. It's the 108th day of the year. 257 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 59 and the normal low is 38. I've calculated the 31-year averages at 64 and 40.

On the warm side, in 2002 the high was the record high of 89 with a low of 63. In 1985 the high was 83 with a low of 62. In 2004 the high was 86 with a low of 52, a 34 degree spread. A decade earlier, in 1994, the high was 84 with a low of 50, a 34 degree spread. In 2005 the high was 83 with a low of 45, a 38 degree spread. In 1996 the high was 76 with a low of 51. A year earlier, in 1995, the high was 76 with a low of 47. In 1987 the high was 77 with a low of 45, a 32 degree spread. Other warm highs were 75 two years ago and 73 last year. The record warmest low of 66 was set way back in 1896. 15 of the last 31 highs were: 50s (8) and 60s (7). On the warmer side, 11 highs were: 70s (6) and 80s (5). On the colder side, five highs were: 30s (1) and 40s (4).

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 86 with a low of 59, a warm day. This was also the year of the former record high (88 at Midway). In 1976 the high was 80 with a low of 57, a warm day. 1972 the high was a warm 77 with a low of 45, a 32 degree spread and warm day. In 1969 the high was 46 with a low of 40, a six degree spread. In 1967 the high was a cool 46. In 1966 the high was 76 with a low of 50, a warm day.

More recently, we had a small spreads of seven degrees in 1999 (45/38) and seven degrees in 2003 (46/39). There were large spreads of 33 degrees last year (73/40), 30 degrees two years ago (75/45), 32 degrees in 1980 (70/38) and 37 degrees 1986 (69/32).

On the cold side, in 1983 the high was 37 with the record-tying low of 23. The low of 23 first occurred way back in 1875. Other cold lows were 26 in 1997 and again in 2001. Other cold highs were 45 in 1989, 45 in 1999, 46 in 2003 and 47 in 1984. The record coldest high of 35 was set back in 1926. 14 of the last 31 lows were 30s. Four lows were in the colder 20s. 13 lows were in the warmer: 40s (8), 50s (3) and 60s (2).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:39 and sunrise was at 6:08. Sunset is at 19:38 and twilight ends at 20:08. There's a total of 13 hours, 30 minutes of daylight today and 14 hours, 29 minutes between twilights. Tomorrow twilight begins at 5:37 and sunrise is at 6:06. The moon is waxing crescent. Illumination was 15% at midnight, will be 19% at noon and 23% at midnight tonight. Moonrise was at 8:32 this morning. Moonset is at 28 minutes past midnight. Moonrise is at 9:33 tomorrow morning. Moonlight time is 15 hours, 28 minutes which is 22 minutes shorter than yesterday. - Bernie -