Temperature This Spring
In climatology we use the three whole months of March, April, and May as spring. It makes more sense than the astronomical definition of the March 20 – June 20. As this year demonstrates, summer-like conditions arrive long before the summer solstice. This year the statewide average temperature for spring in Illinois was 59.1 degrees. That makes it the warmest spring on record for Illinois. The statewide records go back to 1895. The five warmest springs in Illinois were:
- 2012 with 59.1 °F
- 1977 with 57.3 °F
- 1921 with 56.0 °F
- 1991 with 56.0 °F
- 2010 with 55.4 °F
May
The statewide average temperature for May in Illinois was 68.1 degrees. That is 5.7 degrees above normal and the 5th warmest May on record, based on preliminary data. The five warmest month of May were:
- 1962 with 69.5 °F
- 1977 with 68.9 °F
- 1896 with 68.8 °F
- 1991 with 68.5 °F
- 2012 with 68.1 °F
Year to date
It was the warmest January-May on record in Illinois with an average temperature of 48.8 °F. What’s interesting is that out of the top five warmest January-May periods, three have occurred in the last 15 years.
- 2012 with 48.8 °F
- 1921 with 47.3 °F
- 1998 with 46.3 °F
- 2006 with 45.8 °F
- 1938 with 45.6 °F
Precipitation
The statewide average precipitation for May in Illinois was 2.4 inches. That is 1.8 inches below normal and 57 percent of normal. That makes it the 21st driest May on record. The driest May was 1934 with 1.03 inches.
The statewide average precipitation for spring in Illinois was 7.71 inches. That is 3.65 inches below normal and the 18th driest spring on record. The driest spring on record was 1934 with 5.16 inches. In case you are wondering, 1988 was the eleventh driest spring at 6.87 inches.
The May 29 US Drought Monitor has several areas in Illinois in “abnormally dry” conditions and far southern Illinois in moderate drought. The good news is that significant rains fell in northwestern Illinois after the map was released so some of those abnormally dry conditions in that part of the state have been washed away.
