Illinois State Water Survey Illinois State Climatologist

Dry and Mild Start to Fall

The preliminary statewide average September temperature was 66.8 degrees, 0.6 degrees above the 1991–2020 average and the 57th warmest on record going back to 1895. The preliminary statewide average total September precipitation was 2.66 inches, 0.53 inches below the 1991–2020 average and the 41st driest on record statewide.     Data are provisional and may change […]

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The Dry April That Wasn’t

April ended colder and wetter than average across the state. The preliminary statewide average April temperature was 49.2 degrees, 3.4 degrees below the 30-year normal and tied for the 27th coldest on record going back to 1895. The preliminary statewide average total April precipitation was 4.36 inches, 0.58 inches above than the 30-year normal and […]

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Illinois First Fall Freeze Climatology

Due to significant planting delays across most of the Midwest this year, I have heard many concerns about an early fall freeze and its potential effects on immature crops. Most plants experience damage from a hard freeze or “killing freeze”, which is typically designated by a daily minimum air temperature at or below 28°F. Even […]

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Frost in Illinois – Not Quite Yet

While cold air moved in behind the low-pressure system that passed through the Midwest this week, it looks like Illinois will likely dodge the freezing temperatures for now. But someday they will come. Here are the median dates for when we see the temperatures drop to 32 or below in fall, as well as the […]

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