Is this weather normal in Mason County?

Illinois · county records since 1895, through September 2026.

Weather › Illinois › Mason County

Mason County just had its warmest September ever recorded, +6° against the usual. Mason County has warmed about 0.5° per decade since 1970.

This week

Usual for Oct 28 to Nov 3: highs near 59°, lows near 38°

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

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usual high for the datewarmercooler

The last 12 months

Oct: +5.2°OctNov: +1.2°NovDec: -2.7°DecJan 2026: -2.2°JanFeb: +3.8°FebMar: +7.0°MarApr: +5.8°AprMay: -0.6°MayJun: -0.6°JunJul: +1.0°JulAug: +0.9°AugSep: +6.1°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: -1.7 inOctNov: -0.9 inNovDec: -0.6 inDecJan 2026: -0.8 inJanFeb: -1.6 inFebMar: +2.7 inMarApr: +3.1 inAprMay: -2.9 inMayJun: +3.8 inJunJul: -1.9 inJulAug: +3.4 inAugSep: -0.7 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 Mason County

MonthUsual high / lowUsual rainWarmestColdest
January34° / 18°2.0 in38.0° 20069.9° 1977
February40° / 22°1.9 in41.0° 201716.4° 1978
March52° / 31°2.5 in55.4° 201225.1° 1960
April65° / 41°4.0 in59.8° 189644.7° 1907
May75° / 53°4.7 in72.4° 201856.6° 1917
June83° / 62°4.5 in80.0° 193466.3° 1903
July86° / 65°4.0 in85.3° 193670.5° 2009
August85° / 63°3.6 in82.1° 194767.7° 1915
September79° / 55°3.3 in73.0° 202659.3° 1918
October66° / 43°3.2 in64.7° 196344.6° 1925
November52° / 33°2.7 in50.0° 200133.6° 1976
December39° / 23°2.1 in40.7° 201515.9° 1983

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

Towns in Mason County

Crime Radar: Havana

Nearby counties