Hermann, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.9 °C (low) to 19 °C (high). Annual precipitation averages 1117.6 Millimeters. Hermann is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.7 °C | 4.5 °C | 59.44 mm |
| February | -4 °C | 7.4 °C | 58.42 mm |
| March | 0.9 °C | 13.2 °C | 80.26 mm |
| April | 6.6 °C | 19.7 °C | 119.13 mm |
| May | 12.4 °C | 24.3 °C | 134.87 mm |
| June | 17.3 °C | 28.8 °C | 115.32 mm |
| July | 19.7 °C | 31.2 °C | 102.36 mm |
| August | 18.4 °C | 30.6 °C | 107.19 mm |
| September | 13.6 °C | 27.1 °C | 101.6 mm |
| October | 6.7 °C | 20.7 °C | 86.36 mm |
| November | 1.1 °C | 13.4 °C | 85.6 mm |
| December | -3.7 °C | 6.9 °C | 67.06 mm |
| Annual | 6.9 °C | 19 °C | 1117.61 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |