Heavy rains fell over Champaign-Urbana, Illinois on Saturday with more rain early Sunday morning. The two-day total through Sunday morning was 4.42 inches at the official NWS COOP station at the Illinois State Water Survey near the corner of First and Windsor in Champaign. Here is the breakdown by day, with the official observation time at 8 am:
- 0.09 inches of rain by 8 am July 12
- 4.33 inches of rain by 8 am July 13
The 4.33 inches for July 13, 2014, at the official, long-term site for Champaign-Urbana, falls short of the historical record 1-day total, which is 5.32 inches of rain from August 12, 1993.
Here are the reports from the CoCoRaHS network for Champaign-Urbana, showing two reports of over 5 inches, and several reports of between 4 and 5 inches.
Here is a wider view showing the rains of the last two days from a NWS product that combines radar and rain gage information. The amounts of 2.5 to 4 inches stretches from Chicago down to east-central Illinois with the heaviest amounts of possibly up to 6 inches in Champaign, Piatt, McLean, and Ford counties.
Based on preliminary data, the statewide average temperature for May in Illinois was 63.9 degrees. That is 1.2 degrees above average and the first month to be above average in Illinois since October 2013.
The statewide average precipitation for May in Illinois was 4.26 inches, just 0.34 inches below average. Below is a map of precipitation throughout the state. This is a radar-based product that is adjusted with rain gauges, resulting in higher resolution than a rain gauge network and more accuracy than a radar-only precipitation measurement. Sometimes hail can mislead the radar into calculating higher rainfall rates. That may have been the case in southern Champaign County, for example.
Some of the heaviest rainfall totals from the CoCoRaHS network for May occurred in Cook County, including Burnham-Hegewisch (IL-CK-82) with 7.64 inches and Homewood (IL-CK-64) with 7.58 inches.
The area of concern for May was the large section of blue across western and central Illinois, representing rainfall totals of only 1 to 3 inches. There are some smaller patches of blue in southern Illinois and far northwestern Illinois as well. One of the drier locations in west-central Illinois was Roseville (IL-WR-2) with only 1.32 inches with all 31 days reported. The US Drought Monitor list parts of western Illinois as “abnormally dry”.
Plots of Temperature and Precipitation
Here are the time series plots for temperature and precipitation departures for each month of 2013 and 2014. In the first plot, one can clearly see the string of very cold months from November 2013 to April 2014. On the second plot, the dryness of late last summer shows up. While March of this year was dry, it was counterbalanced by a wetter than average April.