Serena, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.1 °F (low) to 59.8 °F (high). Annual precipitation averages 38 Inches. Serena is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.9 °F | 30.8 °F | 1.87 in. |
| February | 18.2 °F | 35.0 °F | 1.8 in. |
| March | 27.8 °F | 47.3 °F | 2.39 in. |
| April | 38.4 °F | 60.6 °F | 3.61 in. |
| May | 50.1 °F | 71.9 °F | 4.67 in. |
| June | 60.0 °F | 81.0 °F | 4.61 in. |
| July | 63.4 °F | 83.9 °F | 3.96 in. |
| August | 61.3 °F | 82.0 °F | 3.88 in. |
| September | 53.5 °F | 76.8 °F | 3.41 in. |
| October | 41.7 °F | 63.8 °F | 3.16 in. |
| November | 30.8 °F | 48.9 °F | 2.56 in. |
| December | 20.7 °F | 36.0 °F | 2.07 in. |
| Annual | 40.1 °F | 59.8 °F | 37.99 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 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 |