CHAMPAIGN, Ill. - Illinois has experienced the second wettest June on record, based on preliminary data. The statewide average precipitation for June was 7.8 inches, 3.7 inches above normal, according to State Climatologist Jim Angel of the Illinois State Water Survey (http://www.isws.illinois.edu).
The wettest June on record was in 1902 with 8.4 inches of rainfall. Statewide records extend back to 1895.
The largest rainfall totals occurred in the northern two-thirds of the state where amounts of 7 to 13 inches were common. Meanwhile, far southern Illinois remained closer to normal with amounts ranging from 3 to 6 inches.
Some long-term precipitation gauge sites set records for their wettest June. These include Galesburg with 13.24 inches, Havana with 10.58 inches, and Lincoln with 10.79 inches.
The statewide average temperature for June was 74.9 degrees, 3 degrees above normal. Based on preliminary data, this is the tenth warmest June. The warmest June on record was in 1934 with 78.5 degrees.
Of the 10 wettest Junes in Illinois history, in 7 out of 10 cases rainfall returned to within an inch of normal in July and August. Only in 1993 did the wet conditions persist during the next two months. Drier conditions occurred in July and August only in 1945 and 1947.
"This June had both near-record rainfall and much warmer than normal temperatures. That’s very unusual considering that in most cases, a wet June tends to run on the cool side," concludes Angel.
The Illinois State Water Survey at the University of Illinois at Urbana-Champaign, a division of the Institute of Natural Resource Sustainability, is the primary agency in Illinois concerned with water and atmospheric resources.