Bergen, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.6 °C (low) to 10.9 °C (high). Annual precipitation averages 489.2 Millimeters. Bergen is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -18.2 °C | -7.6 °C | 13.21 mm |
| February | -16.3 °C | -5 °C | 12.7 mm |
| March | -9.4 °C | 1.7 °C | 18.03 mm |
| April | -2 °C | 11.6 °C | 27.69 mm |
| May | 5.3 °C | 19.1 °C | 72.64 mm |
| June | 11.4 °C | 23.8 °C | 95 mm |
| July | 13.9 °C | 27.1 °C | 74.93 mm |
| August | 12.2 °C | 27.1 °C | 54.36 mm |
| September | 7.1 °C | 21.8 °C | 45.47 mm |
| October | -0.2 °C | 12.8 °C | 37.59 mm |
| November | -8 °C | 2.7 °C | 21.34 mm |
| December | -14.9 °C | -4.8 °C | 16.26 mm |
| Annual | -1.6 °C | 10.9 °C | 489.22 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |