Adair, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.5 °C (low) to 21.3 °C (high). Annual precipitation averages 1130.8 Millimeters. Adair 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.9 °C | 8.5 °C | 53.09 mm |
| February | -2 °C | 11.1 °C | 52.83 mm |
| March | 2.7 °C | 16.2 °C | 89.66 mm |
| April | 7.8 °C | 21.3 °C | 113.03 mm |
| May | 13.5 °C | 25.4 °C | 158.24 mm |
| June | 18.6 °C | 30 °C | 122.43 mm |
| July | 20.9 °C | 33.1 °C | 104.65 mm |
| August | 20 °C | 33 °C | 89.66 mm |
| September | 15.3 °C | 28.8 °C | 101.85 mm |
| October | 8.8 °C | 22.6 °C | 100.33 mm |
| November | 2.8 °C | 16.1 °C | 81.28 mm |
| December | -2.1 °C | 9.9 °C | 63.75 mm |
| Annual | 8.5 °C | 21.3 °C | 1130.8 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 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 | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |