May 28: ORD

Today is May 28th. It's the 148th day of the year. 217 days remain. It's week 22 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 74 and the normal low is 52. I've calculated the 31-year averages at 73 and 52.

On the warm side, three years ago the high was a near-record 92 degrees (the record is 93 in 1977) with the record warmest low of 74 (the former record warmest low is 72 in 1941). In 1991 the high was 91 with a low of 69. In 1987 the high was 88 with a low of 68. In 1998 the high was 90 with a low of 60, a 30 degree spread. In 1999 the high was 87 with a low of 63. The other 80s highs were 88 in 1988, 85 in 1980 and 80 in 1994. 20 of the last 31 highs were: 60s (10) and 70s (10). Three highs were in the cooler 50s. Eight highs were in the warmer: 80s (5) and 90s (3).

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 a hot 88 with a low of 62, a hot day. In 1977 the high was a hot 93 with a low of 56, a 37 degree spread and hot. 1977 was the year of the record high. In 1972 the high was 88 with a low of 59. Overall, this wouldn't be a significantly hot day. The high qualifies but the low brought the mean down to 10.5 above normal, a degree short of qualifying as one of the warmest days. In 1971 the high was 68 with a low of 38, a 30 degree spread. In 1970 the high was 80 with a low of 50, a 30 degree spread. In 1969 the high was 90 with a low of 67, a hot day. In 1968 the high was a cool 61. In 1967 the high was a cool 62. In 1965 the high was 52 with a low of 38, a cool day. In 1964 the high was a cool 59 with a low of 44, a cool day. In 1959 the high was 84 with a warm low of 65, a warm day.

More recently, there was a small spread of six degrees in 1983 (59/53). There were large spreads of 34 degrees in 1994 (80/46), 33 degrees in 1981 (79/46) and 30 degrees in 1989 (72/42).

On the cool side, in 1984 the high was 51 with a low of 40. In 1992 the high was 69 with the record (and only 30s) low of 33, a 36 degree spread. Four years later, in 1996, the high was 57 with a low of 46. Other cool highs were 59 in 1983, 60 in 2000, 60 in 2004, 61 in 1985 and 62 two years ago. The record coolest high of 47 was set way back in 1884. 24 of the last 31 lows were: 40s (11) and 50s (13). One low was in the colder 30s and six lows were in the warmer: 60s (5) and 70s (1).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 4:48 and sunrise was at 5:22. Sunset is at 20:20 and twilight ends at 20:54. There's a total of 14 hours, 58 minutes of daylight today and 16 hours, 6 minutes between twilights. Tomorrow twilight begins at 4:48 and sunrise is at 5:21. The moon is waning gibbous, having reached full yesterday at 18:07. Illumination was 100% at midnight, will be 99% at noon and 98% at midnight tonight. Moonset was at 5:33 this morning. Moonrise is at 21:30 this evening. Moonset is 6:29 tomorrow morning. Moonlight time is 8 hours, 3 minutes which is 10 minutes shorter than yesterday.

Memorial Day is in three days. - Bernie -