Montana Annual Rainfall and Climate Data, see below for individual cities 

 Montana Average Annual Precipitation

Montana city precipitation totals

City Avg Annual Precip Avg Annual Snow Avg. days of Precip Avg # thunderstorm days Avg # hail days Avg # severe thunderstorm watches per year Avg # tornado watches per year # of tornadoes reported in county, 1960-2010
Billings 14.77 56.4 96 27 3 2 9 15
Glasgow 11.23 30.8 90 20 1 2 9 35
Great Falls 14.89 58.3 101 25 2 0 6 11
Havre 11.46 43.1 90 20 1 1 5 6
Helena 11.32 46.4 96 30 3 0 5 3
Kalispell 17.21 64.0 132 23 2 0 3 4
Missoula 13.82 45.4 123 23 1 0 3 2
  • Montana Annual Precipitation Average - 15.37 inches, 45th wettest state in the U.S.
  • Montana Tornado Average - 5.4 per year - 31st most in the U.S.
  • Largest reported Tornado in Montana from 1950-2011, 6/23/1953 - 1,320 yards / .75 miles wide
  • Date with highest number of reported Tornadoes in Montana from 1950-2011, June 21st - 19 tornadoes
  • Average time of occurrence of reported Tornadoes in Montana from 1950-2011 - 4:49 pm
  • Montana Annual Lightning Density - 2.4 flashes per square mile - 41st highest in U.S.
  • Record Driest year in Montana from 1895-2012 - 1931, avg precipitation 9.97 inches 
  • Record Wettest year in Montana from 1895-2012 - 1927, avg precipitation 21.73 inches  


Montana Precipitation Records

  • Driest location ranked by lowest annual average precipitation: Belfry, southern Montana, 6.85"
  • Wettest location ranked by highest annual average precipitation: Many Glacier, northwest Montana, 40.85"
  • Snowiest location ranked by highest annual average snowfall: Kings Hill, central Montana, 305.5"
  • State precipitation record for 24 hours - Circle, northeast Montana, 6/19-20/1921, 11.50"
  • State precipitation record for 1 year - Summit, northwest Montana, 1953, 55.51"
  • State snowfall record for 24 hours - Shonkin, central Montana, 5/28-29/1982, 48.0"
  • State snow record for 1 season - Cooke City, southern Montana, 1977-1978,  418.1" 
  • On average, nearly 50% of Montana's annual precipitation falls during the three months of May through July
  • Montana temperature averages and extremes, precipitation and temperature data for all U.S. states and interesting Top 10 U.S. climate extremes

Data sources: National Climatic Data Center, Severe thunderstorm / tornado watch data period is 1999 - 2008, NOAA Storm Prediction Center, Tornado climate data - NOAA Storm Prediction Center, State lightning flash density average - 1997-2011, Vaisala