Hillsdale, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.2 °C (low) to 21.9 °C (high). Annual precipitation averages 831.8 Millimeters. Hillsdale 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 | -4.6 °C | 8.5 °C | 24.89 mm |
| February | -2.8 °C | 10.9 °C | 32 mm |
| March | 2.1 °C | 16.4 °C | 59.94 mm |
| April | 6.8 °C | 21.4 °C | 81.79 mm |
| May | 13.1 °C | 26.6 °C | 112.01 mm |
| June | 18.8 °C | 32.2 °C | 116.33 mm |
| July | 21.2 °C | 35.1 °C | 87.63 mm |
| August | 20.3 °C | 34.2 °C | 94.49 mm |
| September | 15.8 °C | 29.9 °C | 65.28 mm |
| October | 8.7 °C | 22.9 °C | 80.01 mm |
| November | 1.9 °C | 15.6 °C | 41.91 mm |
| December | -3.3 °C | 9.2 °C | 35.56 mm |
| Annual | 8.2 °C | 21.9 °C | 831.84 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |