Nason, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 45.9 °F (low) to 65.9 °F (high). Annual precipitation averages 45.9 Inches. Nason is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.3 °F | 39.9 °F | 3.14 in. |
| February | 26.5 °F | 44.8 °F | 2.75 in. |
| March | 35.2 °F | 55.0 °F | 3.94 in. |
| April | 45.4 °F | 66.9 °F | 5.0 in. |
| May | 55.9 °F | 75.9 °F | 5.25 in. |
| June | 64.5 °F | 84.8 °F | 4.78 in. |
| July | 68.0 °F | 87.7 °F | 4.15 in. |
| August | 65.7 °F | 86.8 °F | 3.13 in. |
| September | 57.5 °F | 80.7 °F | 3.16 in. |
| October | 45.8 °F | 69.2 °F | 3.32 in. |
| November | 35.7 °F | 55.3 °F | 4.1 in. |
| December | 27.6 °F | 44.0 °F | 3.13 in. |
| Annual | 45.9 °F | 65.9 °F | 45.85 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |