Bloomington, Maryland has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.8 °C (low) to 17.5 °C (high). Annual precipitation averages 1037.8 Millimeters. Bloomington is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 3.9 °C | 69.09 mm |
| February | -5.2 °C | 5.9 °C | 69.85 mm |
| March | -1.6 °C | 10.7 °C | 91.44 mm |
| April | 3.4 °C | 18.3 °C | 91.95 mm |
| May | 8.6 °C | 23.2 °C | 112.01 mm |
| June | 13.6 °C | 27.3 °C | 105.66 mm |
| July | 16.1 °C | 29.6 °C | 100.84 mm |
| August | 15.2 °C | 28.9 °C | 93.73 mm |
| September | 11.3 °C | 25.4 °C | 92.96 mm |
| October | 5.3 °C | 18.7 °C | 74.93 mm |
| November | -0.1 °C | 11.8 °C | 62.23 mm |
| December | -3.6 °C | 6 °C | 73.15 mm |
| Annual | 4.8 °C | 17.5 °C | 1037.84 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |