Hereford, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.6 °C (low) to 16.9 °C (high). Annual precipitation averages 1265.2 Millimeters. Hereford is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.1 °C | 3.3 °C | 89.15 mm |
| February | -5.3 °C | 4.9 °C | 71.37 mm |
| March | -1.3 °C | 9.7 °C | 99.31 mm |
| April | 4.3 °C | 16.7 °C | 98.04 mm |
| May | 9.8 °C | 22.1 °C | 105.41 mm |
| June | 14.9 °C | 27 °C | 122.43 mm |
| July | 17.6 °C | 29.6 °C | 129.29 mm |
| August | 16.7 °C | 28.6 °C | 117.35 mm |
| September | 12.6 °C | 24.9 °C | 129.03 mm |
| October | 6.1 °C | 18.2 °C | 111.76 mm |
| November | 0.7 °C | 11.8 °C | 87.38 mm |
| December | -3.1 °C | 6.1 °C | 104.65 mm |
| Annual | 5.6 °C | 16.9 °C | 1265.17 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |