Richfield, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 0.4 °C (low) to 15.3 °C (high). Annual precipitation averages 253 Millimeters. Richfield is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.4 °C | 0.3 °C | 38.35 mm |
| February | -7.8 °C | 3.2 °C | 20.83 mm |
| March | -3.7 °C | 9.2 °C | 25.91 mm |
| April | -0.6 °C | 14.5 °C | 22.1 mm |
| May | 3.9 °C | 19.8 °C | 27.18 mm |
| June | 7.6 °C | 25.1 °C | 16 mm |
| July | 11.6 °C | 31.3 °C | 3.56 mm |
| August | 10.7 °C | 30.7 °C | 7.11 mm |
| September | 6.1 °C | 24.8 °C | 12.95 mm |
| October | 0.3 °C | 16.5 °C | 21.34 mm |
| November | -4.7 °C | 7.6 °C | 22.61 mm |
| December | -8.8 °C | 0.6 °C | 35.05 mm |
| Annual | 0.4 °C | 15.3 °C | 252.99 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |