Milan, New Hampshire has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from -1.1 °C (low) to 11.3 °C (high). Annual precipitation averages 1111.5 Millimeters. Milan is located in USDA Plant Hardiness Zone 4b. 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 | -15.7 °C | -3.7 °C | 74.68 mm |
| February | -15 °C | -1.9 °C | 67.56 mm |
| March | -9.4 °C | 2.8 °C | 75.44 mm |
| April | -2.2 °C | 10.1 °C | 89.41 mm |
| May | 4.2 °C | 17.7 °C | 93.22 mm |
| June | 9.4 °C | 22.5 °C | 114.55 mm |
| July | 12.1 °C | 25.2 °C | 108.2 mm |
| August | 10.9 °C | 24.4 °C | 101.85 mm |
| September | 6.7 °C | 20.3 °C | 81.53 mm |
| October | 1.1 °C | 12.8 °C | 120.9 mm |
| November | -4.3 °C | 5.7 °C | 86.11 mm |
| December | -10.8 °C | -0.6 °C | 98.04 mm |
| Annual | -1.1 °C | 11.3 °C | 1111.49 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 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 | Normal |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |