Swaledale, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.1 °F (low) to 56 °F (high). Annual precipitation averages 36.2 Inches. Swaledale is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.6 °F | 24.6 °F | 0.92 in. |
| February | 11.7 °F | 29.2 °F | 1.07 in. |
| March | 23.8 °F | 41.8 °F | 2.01 in. |
| April | 35.2 °F | 57.1 °F | 3.9 in. |
| May | 47.8 °F | 69.3 °F | 5.14 in. |
| June | 58.5 °F | 79.3 °F | 5.62 in. |
| July | 61.8 °F | 82.2 °F | 4.52 in. |
| August | 59.0 °F | 80.0 °F | 4.04 in. |
| September | 50.1 °F | 74.0 °F | 3.32 in. |
| October | 37.7 °F | 60.6 °F | 2.53 in. |
| November | 25.5 °F | 43.9 °F | 1.73 in. |
| December | 14.4 °F | 30.3 °F | 1.35 in. |
| Annual | 36.1 °F | 56 °F | 36.15 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°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 |