What is the average annual precipitation in Minnesota?
• The average annual precipitation (rainfall plus the water equivalent found in snowfall) in Minnesota ranges from nearly 18 inches in the far northwest to more than 32 inches in the southeast. Precipitation patterns in Minnesota (and across most of the eastern United States) are dictated by proximity to the Gulf of Mexico. Locations closer to the source of warm, moist air provided by the Gulf, receive more precipitation on average. See the normal precipitation maps for Minnesota. • Approximately two thirds of average annual precipitation falls during the warm months of May through September. However, most of this precipitation is returned to the atmosphere through evaporation from land and water surfaces and through transpiration from plants. The net effect of the balance between “deposits” and “withdrawals” during the growing season is that many of Minnesota’s hydrologic systems reach their seasonal lows by the end of September. • It should be noted that average or “normal” is a math
