Heron Lake, Minnesota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.8 °C (low) to 12.8 °C (high). Annual precipitation averages 766.3 Millimeters. Heron Lake is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.3 °C | -4.8 °C | 18.03 mm |
| February | -12.2 °C | -2.3 °C | 21.34 mm |
| March | -5.6 °C | 4.6 °C | 39.88 mm |
| April | 1.2 °C | 13.4 °C | 75.95 mm |
| May | 8.3 °C | 20.2 °C | 106.43 mm |
| June | 14.5 °C | 25.8 °C | 117.09 mm |
| July | 16.6 °C | 27.9 °C | 95.76 mm |
| August | 15 °C | 26.5 °C | 93.98 mm |
| September | 10.3 °C | 23.2 °C | 80.52 mm |
| October | 2.9 °C | 15.2 °C | 59.69 mm |
| November | -4.3 °C | 5.9 °C | 33.02 mm |
| December | -10.9 °C | -1.9 °C | 24.64 mm |
| Annual | 1.8 °C | 12.8 °C | 766.33 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |