October in Illinois – Cool and Wet


October 2012 was cooler and wetter than normal in Illinois. The statewide average precipitation was 3.94 inches, 0.68 inches above normal. The wettest area of the state was between Quincy and Champaign where precipitation totals ranged from 4 to 7 inches. Some of the driest areas were in southern Illinois south of I-64 and in northern Illinois north of I-80. Some of that area had precipitation totals of less than 3 inches. See map below.

The statewide average temperature was 52.2 degrees, 1.9 degrees below normal. Most of the state reached lows of 32 degrees, and much of central and northern Illinois were down to 28 degrees, signalling the end of the growing season for most outdoor plants.

Year to Date

The statewide average precipitation for January-October was 27.1 inches, nearly 5.8 inches below average. This made it the 15th driest January-October and virtually tied with 2005. The driest was in 1901 with 21.99 inches. The second driest was 1988 with 22.10 inches.

The statewide average temperature was 58.9 degrees, 3.4 degrees above normal. That made it the second warmest on record. The warmest was 1921 with 59.2 degrees.

**All temperature and precipitation amounts are preliminary and may change as more data arrives.

October precipitation.
Year to date precipitation deficits. Areas east of St. Louis and in east-central Illinois have managed to erase the severe precipitation deficits from earlier in the year.