Is this weather normal in Union County?

South Dakota · county records since 1895, through September 2026.

Weather › South Dakota › Union County

Every one of the last 12 months ran warmer than usual in Union County. Union County has warmed about 0.4° per decade since 1970.

This week

Usual for Oct 28 to Nov 3: highs near 54°, lows near 31°

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

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usual high for the datewarmercooler

The last 12 months

Oct: +6.6°OctNov: +3.3°NovDec: +1.9°DecJan 2026: +2.0°JanFeb: +10.0°FebMar: +6.9°MarApr: +1.8°AprMay: +1.2°MayJun: +0.8°JunJul: +3.3°JulAug: +0.8°AugSep: +4.6°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: -0.3 inNovDec: -0.3 inDecJan 2026: -0.5 inJanFeb: -0.7 inFebMar: -1.0 inMarApr: +0.0 inAprMay: -1.1 inMayJun: -1.7 inJunJul: +0.2 inJulAug: -1.2 inAugSep: +2.5 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 Union County

MonthUsual high / lowUsual rainWarmestColdest
January28° / 10°0.6 in33.4° 20062.3° 1979
February33° / 14°0.8 in35.6° 1954-1.9° 1936
March46° / 25°1.6 in51.8° 201218.0° 1960
April60° / 36°3.0 in56.1° 191538.0° 2018
May71° / 48°4.0 in71.6° 193452.0° 1907
June81° / 59°4.5 in78.4° 193362.4° 1945
July85° / 63°3.3 in84.4° 193666.7° 1992
August82° / 60°3.4 in79.2° 193665.6° 1915
September76° / 51°3.0 in70.9° 189754.4° 1965
October62° / 38°2.4 in60.1° 196337.8° 1925
November46° / 25°1.3 in46.0° 200119.7° 1896
December32° / 14°0.9 in32.4° 20232.2° 1983

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

Towns in Union County

Crime Radar: North Sioux City

Nearby counties