Diehlstadt, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.9 °C (low) to 20.2 °C (high). Annual precipitation averages 1273.8 Millimeters. Diehlstadt 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.8 °C | 6.2 °C | 94.74 mm |
| February | -1.3 °C | 9.1 °C | 100.08 mm |
| March | 3.2 °C | 14.4 °C | 118.36 mm |
| April | 8.6 °C | 20.7 °C | 134.37 mm |
| May | 14.4 °C | 25.8 °C | 139.95 mm |
| June | 19.1 °C | 30.4 °C | 100.84 mm |
| July | 21 °C | 32.1 °C | 109.22 mm |
| August | 19.6 °C | 31.4 °C | 71.12 mm |
| September | 15.1 °C | 28.2 °C | 81.28 mm |
| October | 8.5 °C | 22.1 °C | 99.57 mm |
| November | 3 °C | 14.3 °C | 110.24 mm |
| December | -1.1 °C | 8.1 °C | 114.05 mm |
| Annual | 8.9 °C | 20.2 °C | 1273.82 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 |