Starr School, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.5 °F (low) to 51.1 °F (high). Annual precipitation averages 22 Inches. Starr School is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.8 °F | 31.6 °F | 1.45 in. |
| February | 14.0 °F | 33.0 °F | 1.52 in. |
| March | 19.8 °F | 39.3 °F | 1.64 in. |
| April | 27.6 °F | 48.1 °F | 1.88 in. |
| May | 35.2 °F | 57.5 °F | 2.6 in. |
| June | 42.0 °F | 65.2 °F | 3.58 in. |
| July | 47.0 °F | 75.6 °F | 1.28 in. |
| August | 45.6 °F | 75.4 °F | 1.13 in. |
| September | 39.1 °F | 65.0 °F | 1.54 in. |
| October | 30.9 °F | 51.1 °F | 1.83 in. |
| November | 23.3 °F | 39.1 °F | 1.97 in. |
| December | 15.7 °F | 31.7 °F | 1.54 in. |
| Annual | 29.5 °F | 51.1 °F | 21.96 in. |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |