Omer, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.4 °C (low) to 13.4 °C (high). Annual precipitation averages 805.2 Millimeters. Omer is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.4 °C | -1.6 °C | 44.96 mm |
| February | -10.3 °C | 0 °C | 39.12 mm |
| March | -5.9 °C | 5.1 °C | 44.45 mm |
| April | 0.3 °C | 12.4 °C | 81.53 mm |
| May | 6.9 °C | 19.3 °C | 89.92 mm |
| June | 12.4 °C | 24.8 °C | 88.39 mm |
| July | 14.9 °C | 27.3 °C | 76.45 mm |
| August | 14.1 °C | 26.3 °C | 87.12 mm |
| September | 10.3 °C | 22.5 °C | 68.83 mm |
| October | 4.2 °C | 15.4 °C | 78.23 mm |
| November | -1.2 °C | 7.6 °C | 59.44 mm |
| December | -6.2 °C | 1.4 °C | 46.74 mm |
| Annual | 2.4 °C | 13.4 °C | 805.18 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |