Riverbend, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.5 °F (low) to 59.6 °F (high). Annual precipitation averages 20.6 Inches. Riverbend is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 21.4 °F | 35.3 °F | 2.17 in. |
| February | 22.3 °F | 40.4 °F | 1.74 in. |
| March | 27.2 °F | 49.7 °F | 1.73 in. |
| April | 32.7 °F | 59.0 °F | 1.82 in. |
| May | 39.5 °F | 68.8 °F | 1.83 in. |
| June | 46.0 °F | 76.3 °F | 2.14 in. |
| July | 50.6 °F | 87.2 °F | 0.88 in. |
| August | 49.4 °F | 86.9 °F | 0.87 in. |
| September | 42.0 °F | 75.9 °F | 1.14 in. |
| October | 34.0 °F | 59.1 °F | 1.89 in. |
| November | 27.0 °F | 42.5 °F | 2.19 in. |
| December | 21.4 °F | 34.0 °F | 2.17 in. |
| Annual | 34.5 °F | 59.6 °F | 20.57 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |