April 27: ORD

Today is April 27th. It's the 117th day of the year. 248 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 63 and the normal low is 41. I've calculated the 31-year averages at 62 and 42.

On the warm side, in 1986 the high was the record high of 87 with a low of 61. Four years later, in 1990, the high was 84 with a low of 62. In 1984 the high was 80 with a low of 56. In 1991 the high was 71 with a low of 58. Last year was the 6th warmest (72/50), just behind 1983 (73/49). Other warm highs were 79 in 1981 and 75 in 2003. The record warmest low of 67 was set back in 1915. 11 of the last 31 highs were 50s. On the warmer side, 15 highs were: 60s (6), 70s (6) and 80s (3). On the cooler side, five 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 1978 the high was 66 with a low of 35, a 31 degree spread. In 1977 the high was a warm 81 with a low of 44, a 37 degree spread. In 1976 the high was a cool 49 with a low of 32, a cool day. In 1974 the high was a warm 82 with a low of 55, a warm day. In 1971 the high was a cold 48. In 1970 the high was 77 with a low of 60, a warm day. In 1969 the low was a warm 55 degrees. In 1966 the high was a cold 43 with a low of 37, a six degree spread and cold day. In 1965 the high was 63 with a low of 32, a 31 degree spread. In 1964 the high was 63 with a warm low of 58, a five degree spread. In 1962 the high was 84 with a low of 66, a warm day. In 1959 the high was a cold 47 with a low of 40, a seven degree spread.

More recently, we had a small spreads of five degrees in 1980 (45/40) and seven degrees in 1999 (53/46). We had large spreads of 40 degrees in 1981 (79/39), 39 degrees in 2003 (75/36), 33 degrees in 2006 (71/38), 32 degrees in 1994 (69/37), 32 degrees in 1993 (66/34) and 30 degrees in 2000 (68/38).

On the cool side, in 1992 the high was 47 with a low of 31. Four years earlier, in 1988, the high was 42 with a low of 36, a six degree spread. Other cool highs were 45 in 1980, 47 in 1979, 48 in 1985 and 50 in 1982. The record low of 29 occurred in 1945 and the record coldest high of 39 was set in 1934. 26 of the last 31 lows were: 30s (16) and 40s (10). Five lows were in the warmer: 50s (3) and 60s (2).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:24 and sunrise was at 5:54. Sunset is at 19:48 and twilight ends at 20:18. There's a total of 13 hours, 54 minutes of daylight today and 14 hours, 54 minutes between twilights. Tomorrow twilight begins at 5:23 and sunrise is at 5:53. The moon is waxing gibbous, heading towards the full Pink moon tomorrow at 7:18. Illumination was 98% at midnight, will be 99% at noon and 100% at midnight tonight. Moonset was at 4:57 this morning. Moonrise is at 19:21. Moonset is at 5:30 tomorrow morning. Moonlight time is 9 hours, 36 minutes which is 45 minutes shorter than yesterday.

National Teacher Day is in eight days. Mother's Day is in 12 days. - Bernie -