Johnson, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33 °F (low) to 52.9 °F (high). Annual precipitation averages 25.6 Inches. Johnson is located in USDA Plant Hardiness Zone 4b. 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 | 2.5 °F | 20.4 °F | 0.63 in. |
| February | 5.7 °F | 24.5 °F | 0.63 in. |
| March | 18.9 °F | 37.3 °F | 1.1 in. |
| April | 32.2 °F | 53.5 °F | 2.46 in. |
| May | 45.6 °F | 67.3 °F | 3.13 in. |
| June | 56.7 °F | 76.8 °F | 3.91 in. |
| July | 60.6 °F | 81.0 °F | 4.06 in. |
| August | 57.8 °F | 79.1 °F | 3.06 in. |
| September | 48.8 °F | 71.9 °F | 2.55 in. |
| October | 35.7 °F | 56.9 °F | 2.37 in. |
| November | 22.3 °F | 40.4 °F | 1.02 in. |
| December | 9.7 °F | 26.0 °F | 0.69 in. |
| Annual | 33 °F | 52.9 °F | 25.61 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 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |