Heron, Montana has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 34.7 °F (low) to 56.9 °F (high). Annual precipitation averages 32.1 Inches. Heron is located in USDA Plant Hardiness Zone 6b. 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 | 23.1 °F | 34.1 °F | 4.13 in. |
| February | 23.5 °F | 39.0 °F | 2.76 in. |
| March | 27.3 °F | 47.1 °F | 3.18 in. |
| April | 32.3 °F | 56.2 °F | 2.27 in. |
| May | 39.1 °F | 66.4 °F | 2.56 in. |
| June | 45.3 °F | 72.1 °F | 2.73 in. |
| July | 49.1 °F | 82.3 °F | 1.09 in. |
| August | 48.0 °F | 82.6 °F | 0.94 in. |
| September | 41.5 °F | 71.8 °F | 1.46 in. |
| October | 34.5 °F | 55.8 °F | 2.98 in. |
| November | 29.0 °F | 41.4 °F | 3.85 in. |
| December | 23.2 °F | 33.6 °F | 4.13 in. |
| Annual | 34.7 °F | 56.9 °F | 32.08 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 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |