Richfield, Minnesota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.9 °C (low) to 12.7 °C (high). Annual precipitation averages 849.1 Millimeters. Richfield is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -13.4 °C | -4.8 °C | 25.4 mm |
| February | -11.6 °C | -2.2 °C | 23.62 mm |
| March | -4.9 °C | 4.8 °C | 44.45 mm |
| April | 2.4 °C | 13.2 °C | 78.99 mm |
| May | 9.4 °C | 20.2 °C | 106.43 mm |
| June | 15.2 °C | 25.7 °C | 123.19 mm |
| July | 17.9 °C | 28.2 °C | 107.44 mm |
| August | 16.5 °C | 26.8 °C | 112.78 mm |
| September | 11.7 °C | 22.6 °C | 83.06 mm |
| October | 4.3 °C | 14.5 °C | 68.07 mm |
| November | -2.8 °C | 5.7 °C | 42.93 mm |
| December | -9.7 °C | -1.9 °C | 32.77 mm |
| Annual | 2.9 °C | 12.7 °C | 849.13 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |