Bradford, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4 °C (low) to 15 °C (high). Annual precipitation averages 968.5 Millimeters. Bradford is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.2 °C | -1.2 °C | 46.99 mm |
| February | -8.4 °C | 1.3 °C | 49.02 mm |
| March | -2.7 °C | 8.4 °C | 59.69 mm |
| April | 3.3 °C | 15.4 °C | 94.23 mm |
| May | 9.9 °C | 21.5 °C | 120.14 mm |
| June | 15.3 °C | 26.4 °C | 114.81 mm |
| July | 17.1 °C | 28.2 °C | 104.39 mm |
| August | 15.8 °C | 27.4 °C | 97.54 mm |
| September | 11.2 °C | 24.3 °C | 90.93 mm |
| October | 4.8 °C | 17.3 °C | 73.15 mm |
| November | -1.4 °C | 9.1 °C | 65.28 mm |
| December | -7 °C | 1.9 °C | 52.32 mm |
| Annual | 4 °C | 15 °C | 968.49 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |