Overview
September featured well above normal temperatures for all of central and southeast Illinois, and precipitation that ranged from well below normal for much of the area, to well above normal in isolated areas that saw more frequent thunderstorms. The month started out with a hot stretch, when southwest flow and plentiful sunshine boosted highs into the low to mid 90s for several days. There were only a couple brief cool snaps which saw temperatures dip a few degrees below normal, which resulted in monthly averages of 3-7 degrees above normal. Peoria set their warmest September on record with an average temperature of 73.5, or 7.4 degrees above normal.
While most days were dry, a few heavy rain events occurred. Notable events occurred on Thursday September 10th, and Friday, September 18th, when two separate frontal boundaries produced locally heavy rainfall, and isolated hail and damaging wind gusts. Repeated storms resulted in a monthly rain total of 11.74 inches at Hoopeston (northern Vermilion County), and many areas from Danville through Champaign to southeast McLean County received 5 to 8 inches of rain during September. However, west central Illinois was fairly dry, with rainfall totals only about 50-75% of normal, and some areas were classified as "abnormally dry" on the Drought Monitor by the end of the month.
Rainfall
Temperatures
Climate Data
The table below summarizes September rainfall and temperature, and departure from normal for selected cities across central and southeast Illinois. Data from Peoria and Springfield are from ASOS sites, while others are from NWS Cooperative Observers.
Site |
Rainfall |
Departure from Normal | Average Temperature |
Departure from Normal |
Danville |
5.23" |
+2.30" | 69.9 | +3.2 |
Decatur |
1.57" |
-1.57" | 71.0 | +3.2 |
Effingham |
2.28" |
N/A | 71.1 | N/A |
Flora |
1.65" | -1.49" | 71.4 | +3.6 |
Galesburg |
1.53" |
-1.94" | 70.3 | +5.6 |
Jacksonville |
1.45" | -2.08" | 70.9 | +5.2 |
Lincoln |
4.68 |
+1.47" | 69.8 | +3.9 |
Mattoon |
1.93" | -1.29" | N/A | N/A |
Normal |
3.48" |
+0.34" | 70.9 | +5.8 |
Olney |
1.07" | -2.0 | 71.2 | +3.4 |
Paris |
3.00" | -0.18" | 69.1 | +2.6 |
Peoria |
3.25" |
+0.10" | 73.5 | +7.4 |
Springfield |
4.29" |
+1.39" | 72.7 | +5.9 |
Urbana |
6.44" |
+3.31" | 69.8 | +3.6 |
Links below are the monthly climate summaries for area cities. Only the summaries for Peoria, Springfield and Lincoln are considered "official", meaning they are the station of record for their respective locations. The other summaries are "supplemental", meaning another location in the area is the official climate station for that city.
Climate data for other area cities is available at http://www.nws.noaa.gov/climate/xmacis.php?wfo=ilx