August

September 2, 2014

Wet August Wraps Up Cool, Wet Summer in Illinois

Highlights: The 12th wettest August in Illinois finishes out the 10th wettest summer on record. While August was slightly warmer than average, the summer was cooler than average. Here are the statistics.

August Statistics

The statewide average precipitation for August was 5.18 inches, 1.59 inches above average and the 12th wettest on record. The wettest area of the state was Cook County. The largest monthly total was from a CoCoRaHS site (IL-CK-100) in Cicero with 10.20 inches of precipitation.

This first map shows several areas across the state with amounts of 7 to 10 inches (oranges and reds), according to radar estimates. There were a few areas in the northwest and east-central Illinois with only 2 to 3 inches. The second map shows the departures from average, showing the many areas with 2 to 8 inches above average for the month.

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August 31, 2012

August Near-Normal But Summer Hot, Dry for Illinois

After months of exceptionally warm temperatures and drought, Illinois finally experienced temperatures and precipitation closer to normal in August.
The statewide average temperature for August was 73.5 degrees, just 0.1 degree below normal. That’s about as “normal” as you can get.
The statewide average precipitation for August was 3.4 inches, which is 95 percent of normal. In the map below, areas in yellow and orange had 3 to 5 inches, while the areas in red had more than 6 inches. Areas in northern and western Illinois in green received less than 2.5 inches. The largest rainfall total in the state was at Grayville in southeast Illinois with 10.69 inches. In second place was Hoopeston with 8.33 inches.

Summer

The statewide average temperature for the three summer months of June, July, and August was 76.1 degrees, 2.6 degrees above normal. It was the eighth warmest summer on record in Illinois. The warmest was 1936 at 78.6 degrees.
The statewide average precipitation for June-August was 6.64 inches, 5.21 inches below normal. It was the sixth driest summer on record in Illinois. The driest was 1988 with 6.17 inches.

Year to Date

The statewide average temperature for January-August was 59.0 degrees, 4.2 degrees above normal. It was the warmest January-August on record in Illinois. The second warmest was 1921 with 58.3 degrees.
The statewide average precipitation for January-August was 17.45 inches, 7.31 inches below normal. It was the fourth driest January-August on record in Illinois. The driest was 1936 with 14.95 inches, followed by 1988 with 17.12 inches, and 1934 with 17.41 inches.

August 30, 2012

Drought Eases Slightly in Illinois

Drought eases slightly in Illinois thanks to the rainfall and cooler temperatures of the last few weeks. The US Drought Monitor for August 28 shows improvement in northeast Illinois, especially Cook County.
While not yet reflected in the Drought Monitor, August has been a better month than July with more rain and milder temperatures. I’ll post the end of the month stuff on Friday. In the meantime, here are the latest departures from normal for the month so far (second figure). Parts of western and central Illinois as well as much of Illinois north of Interstate 80 have been below normal, areas in east-central and southern Illinois received above-normal precipitation for the month.
Of course, the real game-changer is yet to come – Tropical Storm Isaac. More on that later.

il_dm (1) — US Drought Monitor status for Illinois. Click to enlarge.

prcp_mpe_m2d_dev_20120829 — August precipitation, departure from normal. Areas in green and blue are above-normal. Map courtesy of the Midwestern Regional Climate Center. Click to enlarge.

August 27, 2012

Rain Across the Northern Half of Illinois

We had some decent rainfall amounts in much of the northern half of the state in the last 24 hours. In this image from the NWS Southern Region, green is good – meaning that between 1 and 2 inches fell in those areas. Areas in blue received 3/4 of an inch or less.
Here in Champaign, we had 2.07 inches at the official site while I had 2.15 inches at my house. This is the largest 24-hour rainfall we have had since April 26, 2011. Also, it brings our monthly total to 5.56 inches, which is 1.63 inches above normal for August.
The second figure shows the precipitation departures from normal for August so far. Areas in green and blue are above normal, areas in gray are near normal, and areas in yellow are still below normal. Parts of northern Illinois are below normal as well as a wedge extending from Quincy to Decatur.
However, if you are thinking the drought is fading, the last map shows the precipitation deficits since January 1, 2012. Large areas of Illinois are still 8 to 12 inches below normal (yellow) and a few areas in central and southern Illinois are 12 to 16 inches below normal (red). We have a long ways to go before this drought is over.