Hammon, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.9 °C (low) to 22.5 °C (high). Annual precipitation averages 703.6 Millimeters. Hammon is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.4 °C | 10 °C | 23.11 mm |
| February | -2.8 °C | 12 °C | 25.15 mm |
| March | 1.9 °C | 17.3 °C | 51.31 mm |
| April | 6.8 °C | 22.2 °C | 67.31 mm |
| May | 12.8 °C | 26.9 °C | 99.57 mm |
| June | 18.4 °C | 31.9 °C | 92.71 mm |
| July | 20.8 °C | 35 °C | 57.91 mm |
| August | 19.9 °C | 34.4 °C | 83.31 mm |
| September | 15.6 °C | 29.9 °C | 66.8 mm |
| October | 8.2 °C | 23.3 °C | 64.77 mm |
| November | 1.5 °C | 16.4 °C | 37.34 mm |
| December | -3.6 °C | 10.4 °C | 34.29 mm |
| Annual | 7.9 °C | 22.5 °C | 703.58 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |