Norris, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 30.6 °F (low) to 57.6 °F (high). Annual precipitation averages 16.4 Inches. Norris is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.3 °F | 35.6 °F | 0.5 in. |
| February | 16.4 °F | 38.5 °F | 0.52 in. |
| March | 23.0 °F | 47.0 °F | 1.08 in. |
| April | 29.4 °F | 54.9 °F | 2.13 in. |
| May | 36.9 °F | 64.0 °F | 2.74 in. |
| June | 43.4 °F | 72.9 °F | 3.01 in. |
| July | 48.6 °F | 83.9 °F | 1.14 in. |
| August | 46.8 °F | 83.4 °F | 1.02 in. |
| September | 40.0 °F | 73.3 °F | 1.3 in. |
| October | 31.1 °F | 58.7 °F | 1.68 in. |
| November | 22.2 °F | 44.0 °F | 0.87 in. |
| December | 14.6 °F | 35.1 °F | 0.45 in. |
| Annual | 30.6 °F | 57.6 °F | 16.44 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |