Lewistown Montana Climate Data

Monthly Average Climate Data for Lewistown Montana

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-10.1 °C1.5 °C14.99 mm
February-9.8 °C2 °C16 mm
March-5.8 °C6.8 °C20.32 mm
April-1.2 °C11.7 °C44.96 mm
May3.4 °C16.7 °C59.18 mm
June8.1 °C22.4 °C84.84 mm
July11.1 °C27.3 °C44.2 mm
August10.3 °C27.2 °C38.1 mm
September5.6 °C21.4 °C33.02 mm
October-0.2 °C13.6 °C29.21 mm
November-5.6 °C6.7 °C17.27 mm
December-9.7 °C1.9 °C13.72 mm
Annual-0.3 °C13.3 °C415.81 mm

Climate Data for Lewistown Montana

Average First Frost DateSep. 21 - Sep. 30
Average Last Frost DateJun. 1 - Jun. 10
Average Days With FrostOver 180 Days
Plant Hardiness Zone - 2023Zone 4b : -31.7°C to -28.9°C
Plant Hardiness Zone - 2012Zone 4a : -34.4°C to -31.7°C
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfb - Humid Continental Mild Summer, Wet All Year
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