Pontiac, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.2 °C (low) to 21.1 °C (high). Annual precipitation averages 1177.1 Millimeters. Pontiac 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.2 °C | 8.3 °C | 75.69 mm |
| February | -1.6 °C | 11 °C | 73.41 mm |
| March | 2.6 °C | 15.9 °C | 113.03 mm |
| April | 7.6 °C | 21.8 °C | 131.83 mm |
| May | 12.8 °C | 25.4 °C | 126.75 mm |
| June | 17.8 °C | 30.1 °C | 98.04 mm |
| July | 19.7 °C | 32.4 °C | 93.22 mm |
| August | 18.7 °C | 32.1 °C | 82.55 mm |
| September | 14.4 °C | 28.2 °C | 93.98 mm |
| October | 8.1 °C | 22.3 °C | 93.22 mm |
| November | 2.8 °C | 15.6 °C | 109.73 mm |
| December | -1.6 °C | 9.7 °C | 85.6 mm |
| Annual | 8.2 °C | 21.1 °C | 1177.05 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 7b : -15°C to -12.2°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 |