Tennant, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38.2 °F (low) to 59.2 °F (high). Annual precipitation averages 34 Inches. Tennant 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 11.1 °F | 29.4 °F | 0.81 in. |
| February | 15.4 °F | 34.3 °F | 1.03 in. |
| March | 26.1 °F | 47.6 °F | 1.88 in. |
| April | 37.0 °F | 60.4 °F | 3.52 in. |
| May | 49.4 °F | 70.9 °F | 4.97 in. |
| June | 59.7 °F | 80.6 °F | 5.01 in. |
| July | 63.4 °F | 83.8 °F | 3.79 in. |
| August | 60.6 °F | 81.8 °F | 4.15 in. |
| September | 51.5 °F | 76.0 °F | 3.43 in. |
| October | 40.0 °F | 63.6 °F | 2.64 in. |
| November | 27.2 °F | 47.2 °F | 1.48 in. |
| December | 17.4 °F | 34.4 °F | 1.29 in. |
| Annual | 38.2 °F | 59.2 °F | 34 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |