Essex, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.5 °C (low) to 20.2 °C (high). Annual precipitation averages 1281.2 Millimeters. Essex 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.6 °C | 6.3 °C | 93.22 mm |
| February | -0.8 °C | 9 °C | 95.76 mm |
| March | 3.6 °C | 14.4 °C | 118.11 mm |
| April | 9.1 °C | 20.8 °C | 141.22 mm |
| May | 14.9 °C | 25.8 °C | 130.3 mm |
| June | 19.7 °C | 30.5 °C | 89.92 mm |
| July | 21.6 °C | 31.9 °C | 111.25 mm |
| August | 20.3 °C | 31.4 °C | 79.5 mm |
| September | 16 °C | 28.2 °C | 89.15 mm |
| October | 9.3 °C | 22.1 °C | 102.36 mm |
| November | 3.5 °C | 14.3 °C | 115.06 mm |
| December | -0.8 °C | 8.2 °C | 115.32 mm |
| Annual | 9.5 °C | 20.2 °C | 1281.17 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |