
| Month | Low | High |
|---|---|---|
| Jan | 9.9°F | 30.5°F |
| Feb | 15.6°F | 37.3°F |
| Mar | 23.5°F | 46.8°F |
| Apr | 31.2°F | 56.9°F |
| May | 39.8°F | 65.9°F |
| Jun | 47.5°F | 75.0°F |
| Jul | 52.3°F | 83.4°F |
| Aug | 50.8°F | 82.5°F |
| Sept | 41.2°F | 71.0°F |
| Oct | 31.2°F | 58.4°F |
| Nov | 20.3°F | 41.5°F |
| Dec | 11.3°F | 31.5°F |
Helena's coldest month is January when the average temperature overnight is 9.9°F. In July, the warmest month, the average day time temperature rises to 83.4°F.

| Month | Precipitation |
|---|---|
| Jan | 0.52in. |
| Feb | 0.38in. |
| Mar | 0.63in. |
| Apr | 0.91in. |
| May | 1.78in. |
| Jun | 1.82in. |
| Jul | 1.34in. |
| Aug | 1.29in. |
| Sept | 1.05in. |
| Oct | 0.66in. |
| Nov | 0.48in. |
| Dec | 0.46in. |
The driest month in Helena is February with 0.38 inches of precipitation, and with 1.82 inches June is the wettest month.