Is this weather normal in LaSalle County?

Illinois · county records since 1895, through September 2026.

Weather › Illinois › LaSalle County

LaSalle County just had its 6th-warmest September in 132 years, +4° against the usual. LaSalle County has warmed about 0.4° per decade since 1970.

This week

Usual for Oct 28 to Nov 3: highs near 56°, lows near 36°

That is the 1991 to 2020 average for these dates in LaSalle County. The Weather Service forecast fills in below.

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usual high for the datewarmercooler

The last 12 months

Oct: +4.4°OctNov: +1.3°NovDec: -3.4°DecJan 2026: -2.2°JanFeb: +4.4°FebMar: +5.8°MarApr: +5.3°AprMay: -1.0°MayJun: -0.9°JunJul: +1.1°JulAug: +0.3°AugSep: +4.2°Sepwarmercooler

Each bar is a month's average temperature against the usual for that month (1991 to 2020). Ranks compare the same month in every year since 1895.

Every year since 1895

18952025

Rain and drought

Oct: -1.3 inOctNov: -0.2 inNovDec: 0.0 inDecJan 2026: -0.6 inJanFeb: -1.6 inFebMar: +1.5 inMarApr: +2.9 inAprMay: -2.8 inMayJun: +3.8 inJunJul: -0.7 inJulAug: +4.0 inAugSep: +0.6 inSepwetterdrier

Rain and melted snow against the usual for each month. The drought reading is NOAA's Palmer index for the county.

Month by month in LaSalle County

MonthUsual high / lowUsual rainWarmestColdest
January31° / 15°1.9 in34.9° 20067.2° 1918
February36° / 19°1.7 in38.4° 199811.2° 1936
March48° / 29°2.3 in53.7° 201222.7° 1960
April62° / 38°3.6 in56.9° 201041.0° 1907
May73° / 50°4.6 in68.4° 197753.1° 1917
June82° / 59°4.4 in76.8° 193463.9° 1903
July84° / 63°3.9 in80.3° 193668.3° 2009
August83° / 61°3.7 in80.1° 194763.9° 1915
September77° / 54°3.4 in70.0° 193156.7° 1918
October64° / 42°3.1 in62.5° 196342.1° 1925
November49° / 31°2.5 in48.9° 200130.7° 1959
December36° / 21°2.0 in38.8° 201514.1° 2000

Warmest and coldest are the month's whole-month average temperature, with the year it happened.

Towns in LaSalle County

Crime Radar: Ottawa, Peru, Marseilles, Streator, Oglesby

Nearby counties