Norris, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.5 °F (low) to 61.1 °F (high). Annual precipitation averages 39.3 Inches. 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 | 15.0 °F | 32.1 °F | 1.84 in. |
| February | 18.4 °F | 36.8 °F | 1.96 in. |
| March | 28.6 °F | 49.4 °F | 2.51 in. |
| April | 39.3 °F | 62.3 °F | 3.94 in. |
| May | 51.3 °F | 72.9 °F | 5.21 in. |
| June | 61.0 °F | 81.8 °F | 4.71 in. |
| July | 64.1 °F | 84.9 °F | 4.1 in. |
| August | 61.8 °F | 83.3 °F | 3.51 in. |
| September | 53.6 °F | 77.7 °F | 3.66 in. |
| October | 41.9 °F | 65.1 °F | 3.0 in. |
| November | 30.4 °F | 50.0 °F | 2.74 in. |
| December | 20.8 °F | 37.4 °F | 2.16 in. |
| Annual | 40.5 °F | 61.1 °F | 39.34 in. |
| 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 : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |