Delhi, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 35.9 °F (low) to 56.4 °F (high). Annual precipitation averages 39.5 Inches. Delhi 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 | 8.3 °F | 25.9 °F | 1.24 in. |
| February | 12.2 °F | 30.4 °F | 1.32 in. |
| March | 23.9 °F | 43.5 °F | 2.14 in. |
| April | 35.0 °F | 57.3 °F | 3.97 in. |
| May | 46.9 °F | 68.9 °F | 4.75 in. |
| June | 57.4 °F | 78.6 °F | 5.98 in. |
| July | 60.6 °F | 81.6 °F | 4.74 in. |
| August | 58.2 °F | 79.8 °F | 4.5 in. |
| September | 49.3 °F | 73.5 °F | 3.88 in. |
| October | 37.5 °F | 60.4 °F | 3.04 in. |
| November | 25.8 °F | 44.8 °F | 2.29 in. |
| December | 15.3 °F | 31.7 °F | 1.67 in. |
| Annual | 35.9 °F | 56.4 °F | 39.52 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 |