Norris, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.7 °C (low) to 16.2 °C (high). Annual precipitation averages 999.2 Millimeters. Norris is located in USDA Plant Hardiness Zone 5b. 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 | -9.4 °C | 0.1 °C | 46.74 mm |
| February | -7.6 °C | 2.7 °C | 49.78 mm |
| March | -1.9 °C | 9.7 °C | 63.75 mm |
| April | 4.1 °C | 16.8 °C | 100.08 mm |
| May | 10.7 °C | 22.7 °C | 132.33 mm |
| June | 16.1 °C | 27.7 °C | 119.63 mm |
| July | 17.8 °C | 29.4 °C | 104.14 mm |
| August | 16.6 °C | 28.5 °C | 89.15 mm |
| September | 12 °C | 25.4 °C | 92.96 mm |
| October | 5.5 °C | 18.4 °C | 76.2 mm |
| November | -0.9 °C | 10 °C | 69.6 mm |
| December | -6.2 °C | 3 °C | 54.86 mm |
| Annual | 4.7 °C | 16.2 °C | 999.22 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |