The statewide average precipitation for June 2015 in Illinois was 9.53 inches, based on available data through June 30. That is 5.33 inches above the average June precipitation, and the wettest June on record for Illinois.
Here are the top ten wettest June totals. Note that 7 out of the 10 wettest June totals have occurred since 1993.
- 2o15 with 9.53 inches
- 1902 with 8.27 inches
- 2010 with 7.71 inches
- 1998 with 7.64 inches
- 2000 with 7.34 inches
- 1928 with 6.93 inches
- 1993 with 6.85 inches
- 1924 with 6.80 inches
- 2014 with 6.77 inches
- 2011 with 6.69 inches
In addition to being the wettest June on record, it is the second wettest month on record for Illinois. Only September 1926 was wetter at 9.62 inches – just 0.09 inches higher.
While the statewide average was 9.53 inches, several sites have reported much more than that. A CoCoRaHS observer near Ashkum IL (Iroquois County) reported a monthly total of 17.20 inches. A CoCoRaHS observer in Chebanse (Kankakee County) reported a monthly total of 16.17 inches. The CoCoRaHS network is composed of all-volunteer observers with standard rain gauges and training, providing reliable reports around the state.
Here are the precipitation maps for June – the first with the total amounts and the second with the departures from average. In the first map, there are several areas of the state with 12 inches or more of precipitation. The darker purple area in Iroquois and Kankakee Counties indicate amounts of 12 to 18 inches and are in line with the CoCoRaHS reports in that area.
The statewide average temperature for June was 71.9 degrees, 0.1 degrees above average.