Castle, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.2 °C (low) to 22.5 °C (high). Annual precipitation averages 1064.5 Millimeters. Castle is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.8 °C | 10.3 °C | 46.23 mm |
| February | 0.1 °C | 12.6 °C | 50.55 mm |
| March | 5 °C | 17.7 °C | 78.99 mm |
| April | 9.6 °C | 22.4 °C | 106.43 mm |
| May | 14.9 °C | 26.3 °C | 145.54 mm |
| June | 19.8 °C | 31.1 °C | 130.05 mm |
| July | 21.8 °C | 34.1 °C | 93.98 mm |
| August | 21.2 °C | 34.1 °C | 78.23 mm |
| September | 17.1 °C | 29.8 °C | 103.63 mm |
| October | 10.6 °C | 23.6 °C | 101.35 mm |
| November | 4.7 °C | 17.1 °C | 71.63 mm |
| December | -0.2 °C | 11.2 °C | 57.91 mm |
| Annual | 10.2 °C | 22.5 °C | 1064.52 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |