Idaho Annual Rainfall see below for individual cities 


 

Idaho city precipitation totals

City

Avg Annual Precip

Avg Snow Annual

 Avg. days of Precip Avg # snow days Avg # thunderstorm days Avg # hail days
Boise 12.19 20.4 90 55 10 2
Lewiston 12.74 15.7 103 44 27 0
Pocatello 12.58 42.0 96 81 24 1
State Average - 18.96 inches, 42nd wettest in U.S.

Idaho Precipitation Records 

  • Driest location ranked by lowest annual average precipitation: Grand View, southwestern Idaho, 7.11"
  • Wettest location ranked by highest annual average precipitation: Burke, northern Idaho, 48.87" 
  • Snowiest location ranked by highest annual average snowfall: Mullan Pass, northern Idaho, 283.5"
  • State precipitation record for 24 hours - Rattlesnake Pass, northern Idaho, 11/23/1909, 7.17"
  • State precipitation record for 1 year - Roland, northern Idaho, 1933, 81.05"
  • State snowfall record for 24 hours - Sun Valley, central Idaho, 2/11/1959, 38.00"
  • State snow record for 1 season - Roland, northern Idaho, 1949-1950, 441.8"
  • On 1/03/1961, a three day long ice storm hit northern Idaho, producing an accumulation 
of ice eight inches thick, a U.S. record
  • Floods in Idaho occur most often during the period of seasonal snowmelt in spring, particularly 
in April and May. A few areas in the State are actually flooded or threatened by floodwaters nearly every year. 
These areas include the Kootenai River valley and in the vicinity of Bonners Ferry. Another area is the Snake River 
upstream from Idaho Falls in the areas of Roberts and Menan.

Precipitation data for other U.S. states
Data source: National Data Climatic Center