Iron Post, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9 °C (low) to 21.5 °C (high). Annual precipitation averages 1182.4 Millimeters. Iron Post is located in USDA Plant Hardiness Zone 7b. 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 | -3.3 °C | 8.9 °C | 59.69 mm |
| February | -1.3 °C | 11.4 °C | 58.93 mm |
| March | 3.4 °C | 16.6 °C | 96.01 mm |
| April | 8.2 °C | 21.6 °C | 119.63 mm |
| May | 13.8 °C | 25.6 °C | 156.97 mm |
| June | 18.8 °C | 30.1 °C | 124.97 mm |
| July | 21.1 °C | 33.1 °C | 100.58 mm |
| August | 20.3 °C | 32.9 °C | 89.15 mm |
| September | 15.7 °C | 28.8 °C | 110.74 mm |
| October | 9.2 °C | 22.7 °C | 105.41 mm |
| November | 3.3 °C | 16.2 °C | 88.9 mm |
| December | -1.5 °C | 10.3 °C | 71.37 mm |
| Annual | 9 °C | 21.5 °C | 1182.35 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |