Antrim, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.6 °C (low) to 13.7 °C (high). Annual precipitation averages 1244.1 Millimeters. Antrim is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.3 °C | -0.7 °C | 88.65 mm |
| February | -10.7 °C | 1.1 °C | 83.57 mm |
| March | -6.1 °C | 5.5 °C | 99.06 mm |
| April | 0 °C | 13.1 °C | 99.82 mm |
| May | 6.2 °C | 19.4 °C | 97.28 mm |
| June | 11.4 °C | 24.3 °C | 113.28 mm |
| July | 14.2 °C | 27.1 °C | 103.63 mm |
| August | 13 °C | 26.2 °C | 101.09 mm |
| September | 8.8 °C | 22.2 °C | 106.93 mm |
| October | 2.8 °C | 14.9 °C | 134.62 mm |
| November | -2.2 °C | 8.5 °C | 101.35 mm |
| December | -7.4 °C | 2.4 °C | 114.81 mm |
| Annual | 1.6 °C | 13.7 °C | 1244.09 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |