Richfield, Minnesota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.2 °F (low) to 54.9 °F (high). Annual precipitation averages 33.4 Inches. 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 | 7.8 °F | 23.3 °F | 1.0 in. |
| February | 11.1 °F | 28.1 °F | 0.93 in. |
| March | 23.1 °F | 40.7 °F | 1.75 in. |
| April | 36.3 °F | 55.7 °F | 3.11 in. |
| May | 49.0 °F | 68.4 °F | 4.19 in. |
| June | 59.4 °F | 78.2 °F | 4.85 in. |
| July | 64.2 °F | 82.7 °F | 4.23 in. |
| August | 61.7 °F | 80.3 °F | 4.44 in. |
| September | 53.0 °F | 72.7 °F | 3.27 in. |
| October | 39.7 °F | 58.1 °F | 2.68 in. |
| November | 27.0 °F | 42.3 °F | 1.69 in. |
| December | 14.6 °F | 28.6 °F | 1.29 in. |
| Annual | 37.2 °F | 54.9 °F | 33.43 in. |
| 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 : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |