CHAMPAIGN, Ill. — April 2013 was the fourth wettest on record for Illinois, with 6.90 inches of rain, according to Illinois State Climatologist Jim Angel at the Prairie Research Institute, University of Illinois.
That total was 3.13 inches above the long-term average of 3.77 inches for the month.
This April easily exceeded the combined statewide rainfall totals for Illinois in May, June, and July of 2012, during the worst of the drought. The total rainfall amounts for those months in 2012 were 2.50 inches, 1.80 inches, and 1.48 inches, respectively, which led to a total of only 5.78 inches. That was 1.12 inches less than the amount of rainfall during this April alone.
A small area of southern Illinois experienced below-average rainfall in Illinois. Otherwise, the rainfall across the rest of the state was much above average. The two largest monthly totals for April were Augusta, with 12.28 inches, and Naperville, with 11.03 inches. Several more stations reported totals in the 10-inch range.
In Grundy County, according to the Weather Data Division of the Grundy County Emergency Management Agency, the rainfall total was significantly less than those peaks, but still above the state average.
As recorded at Morris, 7.87 inches of precipitation fell during April.
That amount more than doubled the precipitation total for the year, bringing it to 15.12 inches.
Rain did fall on 16 days during the month, including the 3.88 inches of rain that fell between 8 a.m. on April 17 and 8 a.m. on April 18, precipitating massive flooding throughout the area.
The storm that accompanied that rainfall also brought the month’s peak wind gust, at 51 miles per hour on April 18.
There were actually two major impacts of the wet April. One was the widespread flooding on the Illinois, Wabash, and Mississippi rivers and their tributaries. Several sites along the Illinois, including Morris, reported record-high river crests in April. Because the flooding included the Chicago area, the dollar damages and number of people affected will be quite large.
The second impact of the wet April was the delay in fieldwork. In the April 29 U.S. Department of Agriculture National Agricultural Statistics Service report, only 1 percent of the corn crop was planted, compared to 76 percent last April, and a five-year average of 36 percent.
The statewide average temperature was 50.1 degrees, which was 2.3 degrees below average.
“The average temperature was not record-setting but reflects the fact that we had a lot of cool, cloudy days in April,” Angel concluded.
In Morris, the average temperature was even lower, at 48.5 degrees. There were five days with temperatures below freezing, including the low-mercury level of 23 degrees on April 3. The warmest reading of the month came on April 30, when the temperature climbed to 86 degrees.
There was no additional snowfall during the month of April, which means the county received a total of 16.4 inches of snow during the winter season.
The Illinois State Water Survey at the University of Illinois at Urbana-Champaign, a division of the Prairie Research Institute, is the primary agency in Illinois concerned with water and atmospheric resources.