Riverbend, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.4 °C (low) to 15.3 °C (high). Annual precipitation averages 522.5 Millimeters. 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 | -5.9 °C | 1.8 °C | 55.12 mm |
| February | -5.4 °C | 4.7 °C | 44.2 mm |
| March | -2.7 °C | 9.8 °C | 43.94 mm |
| April | 0.4 °C | 15 °C | 46.23 mm |
| May | 4.2 °C | 20.4 °C | 46.48 mm |
| June | 7.8 °C | 24.6 °C | 54.36 mm |
| July | 10.3 °C | 30.7 °C | 22.35 mm |
| August | 9.7 °C | 30.5 °C | 22.1 mm |
| September | 5.6 °C | 24.4 °C | 28.96 mm |
| October | 1.1 °C | 15.1 °C | 48.01 mm |
| November | -2.8 °C | 5.8 °C | 55.63 mm |
| December | -5.9 °C | 1.1 °C | 55.12 mm |
| Annual | 1.4 °C | 15.3 °C | 522.5 mm |
| 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 : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |