Mason City, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36.4 °F (low) to 62 °F (high). Annual precipitation averages 25.9 Inches. Mason City is located in USDA Plant Hardiness Zone 5b. 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 | 12.5 °F | 36.3 °F | 0.53 in. |
| February | 15.5 °F | 40.0 °F | 0.67 in. |
| March | 24.6 °F | 51.2 °F | 1.45 in. |
| April | 34.6 °F | 61.3 °F | 2.97 in. |
| May | 46.0 °F | 71.2 °F | 4.12 in. |
| June | 57.0 °F | 81.4 °F | 3.75 in. |
| July | 62.2 °F | 86.9 °F | 3.23 in. |
| August | 59.8 °F | 85.0 °F | 3.21 in. |
| September | 49.4 °F | 77.7 °F | 2.44 in. |
| October | 36.0 °F | 64.6 °F | 1.77 in. |
| November | 23.7 °F | 50.1 °F | 1.08 in. |
| December | 15.1 °F | 38.6 °F | 0.72 in. |
| Annual | 36.4 °F | 62 °F | 25.94 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |