Riverdale, North Dakota has a Humid Continental Mild Summer With Dry Winters climate (Köppen classification: Dwb). Average annual temperatures range from 30.1 °F (low) to 51.8 °F (high). Annual precipitation averages 17.9 Inches. Riverdale is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.5 °F | 19.7 °F | 0.46 in. |
| February | 4.6 °F | 24.1 °F | 0.33 in. |
| March | 16.6 °F | 36.6 °F | 0.6 in. |
| April | 28.8 °F | 52.3 °F | 1.16 in. |
| May | 41.4 °F | 65.1 °F | 2.77 in. |
| June | 52.3 °F | 74.0 °F | 3.75 in. |
| July | 57.1 °F | 80.8 °F | 2.71 in. |
| August | 54.8 °F | 81.0 °F | 2.07 in. |
| September | 45.3 °F | 70.6 °F | 1.63 in. |
| October | 32.4 °F | 54.7 °F | 1.37 in. |
| November | 19.1 °F | 38.0 °F | 0.57 in. |
| December | 7.7 °F | 24.7 °F | 0.46 in. |
| Annual | 30.1 °F | 51.8 °F | 17.88 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dwb - Humid Continental Mild Summer With Dry Winters |