Marcus, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.7 °F (low) to 57.1 °F (high). Annual precipitation averages 30.7 Inches. Marcus is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.4 °F | 26.3 °F | 0.71 in. |
| February | 12.6 °F | 30.8 °F | 0.86 in. |
| March | 24.1 °F | 43.9 °F | 1.73 in. |
| April | 35.3 °F | 58.2 °F | 3.27 in. |
| May | 48.3 °F | 70.2 °F | 4.1 in. |
| June | 59.2 °F | 80.0 °F | 4.7 in. |
| July | 62.7 °F | 83.1 °F | 3.5 in. |
| August | 60.2 °F | 80.8 °F | 3.85 in. |
| September | 51.2 °F | 74.8 °F | 3.22 in. |
| October | 38.5 °F | 61.4 °F | 2.36 in. |
| November | 25.3 °F | 44.8 °F | 1.38 in. |
| December | 14.4 °F | 31.2 °F | 0.98 in. |
| Annual | 36.7 °F | 57.1 °F | 30.66 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |