Johnson, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.3 °F (low) to 72.5 °F (high). Annual precipitation averages 39.2 Inches. Johnson is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 27.4 °F | 50.6 °F | 1.54 in. |
| February | 31.0 °F | 54.8 °F | 1.84 in. |
| March | 39.5 °F | 63.7 °F | 2.89 in. |
| April | 48.2 °F | 72.6 °F | 3.85 in. |
| May | 57.9 °F | 79.3 °F | 5.34 in. |
| June | 66.9 °F | 87.7 °F | 5.11 in. |
| July | 70.9 °F | 93.2 °F | 3.5 in. |
| August | 69.4 °F | 93.1 °F | 3.29 in. |
| September | 61.4 °F | 85.3 °F | 3.85 in. |
| October | 49.8 °F | 74.6 °F | 3.65 in. |
| November | 39.0 °F | 62.7 °F | 2.3 in. |
| December | 30.4 °F | 52.2 °F | 2.07 in. |
| Annual | 49.3 °F | 72.5 °F | 39.23 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |