Clontarf, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.7 °C (low) to 12.2 °C (high). Annual precipitation averages 680.2 Millimeters. Clontarf is located in USDA Plant Hardiness Zone 4b. 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 | -16.2 °C | -6.1 °C | 16.26 mm |
| February | -14.4 °C | -3.6 °C | 16.76 mm |
| March | -7.1 °C | 3.4 °C | 33.02 mm |
| April | 0.4 °C | 12.6 °C | 60.45 mm |
| May | 7.7 °C | 20.2 °C | 81.53 mm |
| June | 13.9 °C | 25.6 °C | 105.41 mm |
| July | 15.9 °C | 27.8 °C | 102.36 mm |
| August | 14.2 °C | 26.7 °C | 91.95 mm |
| September | 9.4 °C | 22.8 °C | 66.8 mm |
| October | 2.2 °C | 14.6 °C | 59.44 mm |
| November | -5.3 °C | 4.9 °C | 27.43 mm |
| December | -12.3 °C | -2.9 °C | 18.8 mm |
| Annual | 0.7 °C | 12.2 °C | 680.21 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |