Patterson, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.7 °F (low) to 60.3 °F (high). Annual precipitation averages 35.7 Inches. Patterson 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 | 12.6 °F | 30.6 °F | 0.93 in. |
| February | 16.6 °F | 35.5 °F | 1.23 in. |
| March | 27.4 °F | 48.3 °F | 2.09 in. |
| April | 38.7 °F | 61.6 °F | 3.69 in. |
| May | 50.6 °F | 71.7 °F | 5.07 in. |
| June | 60.8 °F | 81.2 °F | 4.92 in. |
| July | 64.9 °F | 85.2 °F | 4.29 in. |
| August | 62.3 °F | 83.6 °F | 3.95 in. |
| September | 53.4 °F | 77.1 °F | 3.62 in. |
| October | 41.3 °F | 64.0 °F | 2.66 in. |
| November | 29.1 °F | 48.8 °F | 1.92 in. |
| December | 18.2 °F | 35.7 °F | 1.32 in. |
| Annual | 39.7 °F | 60.3 °F | 35.69 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 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |