Shell Valley, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 26.9 °F (low) to 48.4 °F (high). Annual precipitation averages 19.4 Inches. Shell Valley is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.1 °F | 15.0 °F | 0.54 in. |
| February | -0.7 °F | 19.5 °F | 0.54 in. |
| March | 12.3 °F | 31.5 °F | 0.79 in. |
| April | 26.9 °F | 49.7 °F | 0.94 in. |
| May | 39.6 °F | 63.9 °F | 2.51 in. |
| June | 50.6 °F | 72.6 °F | 3.75 in. |
| July | 54.9 °F | 77.6 °F | 3.1 in. |
| August | 52.4 °F | 77.6 °F | 2.56 in. |
| September | 42.9 °F | 67.9 °F | 1.68 in. |
| October | 30.1 °F | 51.6 °F | 1.47 in. |
| November | 15.4 °F | 33.4 °F | 0.79 in. |
| December | 2.4 °F | 19.9 °F | 0.7 in. |
| Annual | 26.9 °F | 48.4 °F | 19.37 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 3b : -35°F to -30°F |
| Plant Hardiness Zone - 2012 | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |