average temperature by month helena montana
Average Temperatures for Helena. Helena's coldest month is January when the average temperature overnight is 9.9Â°F. In July, the warmest month, the average day time temperature rises to 83.4Â°F. Average Rainfall for Helena. The driest month in Helena is February with 0.38 inches of precipitation, and with 1.82 inches June is the wettest month.
The highest monthly average temperature in Helena for July is 74 degrees. The lowest monthly average temperature in Helena for December is 21 degrees. The most monthly precipitation in Helena occurs in June with 2.4 inches. The air quality index in Helena is 29% better than the national average. The pollution index in Helena is 77% better than the national average.