Hamlin, West Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 6.5 °C (low) to 19.7 °C (high). Annual precipitation averages 1178.8 Millimeters. Hamlin is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.7 °C | 6.4 °C | 85.34 mm |
| February | -3.5 °C | 8.7 °C | 78.74 mm |
| March | 0.1 °C | 13.9 °C | 111.76 mm |
| April | 5.4 °C | 21 °C | 93.98 mm |
| May | 10.9 °C | 25.2 °C | 123.44 mm |
| June | 15.8 °C | 29.1 °C | 113.03 mm |
| July | 18 °C | 30.8 °C | 137.92 mm |
| August | 17.3 °C | 30.3 °C | 90.93 mm |
| September | 13.3 °C | 27.3 °C | 85.09 mm |
| October | 6.3 °C | 21.1 °C | 80.77 mm |
| November | 0.8 °C | 14.3 °C | 80.01 mm |
| December | -2.2 °C | 8.6 °C | 97.79 mm |
| Annual | 6.5 °C | 19.7 °C | 1178.8 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |