Clinton, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 30.1 °F (low) to 56.6 °F (high). Annual precipitation averages 19.3 Inches. Clinton is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.0 °F | 32.1 °F | 1.25 in. |
| February | 17.0 °F | 37.2 °F | 1.33 in. |
| March | 23.0 °F | 47.0 °F | 1.54 in. |
| April | 29.2 °F | 55.6 °F | 1.6 in. |
| May | 36.2 °F | 65.1 °F | 2.14 in. |
| June | 42.9 °F | 72.6 °F | 2.7 in. |
| July | 47.1 °F | 84.8 °F | 1.08 in. |
| August | 45.7 °F | 84.2 °F | 1.13 in. |
| September | 38.3 °F | 72.8 °F | 1.45 in. |
| October | 30.0 °F | 56.2 °F | 1.66 in. |
| November | 21.8 °F | 40.5 °F | 1.98 in. |
| December | 14.9 °F | 30.8 °F | 1.43 in. |
| Annual | 30.1 °F | 56.6 °F | 19.29 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |