Ryan, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.2 °F (low) to 56.8 °F (high). Annual precipitation averages 39.3 Inches. Ryan 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 | 8.7 °F | 26.2 °F | 1.22 in. |
| February | 12.6 °F | 30.6 °F | 1.29 in. |
| March | 24.1 °F | 43.8 °F | 2.1 in. |
| April | 35.3 °F | 57.8 °F | 3.9 in. |
| May | 47.1 °F | 69.4 °F | 4.6 in. |
| June | 57.8 °F | 79.0 °F | 6.0 in. |
| July | 61.0 °F | 82.2 °F | 4.6 in. |
| August | 58.4 °F | 80.3 °F | 4.66 in. |
| September | 49.7 °F | 73.9 °F | 3.92 in. |
| October | 37.8 °F | 60.7 °F | 3.04 in. |
| November | 26.1 °F | 45.1 °F | 2.31 in. |
| December | 15.5 °F | 32.0 °F | 1.64 in. |
| Annual | 36.2 °F | 56.8 °F | 39.28 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |