Lamont, Iowa has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.1 °F (low) to 56.6 °F (high). Annual precipitation averages 38.4 Inches. Lamont 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 | 8.1 °F | 25.6 °F | 1.16 in. |
| February | 12.0 °F | 30.0 °F | 1.23 in. |
| March | 24.0 °F | 43.2 °F | 2.06 in. |
| April | 35.3 °F | 57.7 °F | 3.9 in. |
| May | 47.3 °F | 69.6 °F | 4.82 in. |
| June | 58.2 °F | 79.3 °F | 5.84 in. |
| July | 61.2 °F | 82.1 °F | 4.98 in. |
| August | 58.6 °F | 80.1 °F | 4.03 in. |
| September | 50.1 °F | 74.1 °F | 3.69 in. |
| October | 37.8 °F | 61.0 °F | 2.96 in. |
| November | 25.8 °F | 44.7 °F | 2.12 in. |
| December | 15.0 °F | 31.5 °F | 1.6 in. |
| Annual | 36.1 °F | 56.6 °F | 38.39 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 | Dfb - Humid Continental Mild Summer, Wet All Year |