Ritchey, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.9 °C (low) to 20.1 °C (high). Annual precipitation averages 1209.8 Millimeters. Ritchey 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.4 °C | 6.9 °C | 59.44 mm |
| February | -2.7 °C | 9.4 °C | 56.9 mm |
| March | 2.2 °C | 14.8 °C | 96.52 mm |
| April | 7.3 °C | 20.1 °C | 128.52 mm |
| May | 12.8 °C | 24.4 °C | 161.8 mm |
| June | 17.8 °C | 29.2 °C | 128.02 mm |
| July | 20.2 °C | 31.9 °C | 99.31 mm |
| August | 19.2 °C | 31.7 °C | 91.69 mm |
| September | 14.5 °C | 27.6 °C | 118.36 mm |
| October | 8 °C | 21.4 °C | 102.11 mm |
| November | 2.2 °C | 14.5 °C | 94.74 mm |
| December | -2.6 °C | 8.8 °C | 72.39 mm |
| Annual | 7.9 °C | 20.1 °C | 1209.8 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |