Lakeside, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.5 °F (low) to 56 °F (high). Annual precipitation averages 16.3 Inches. Lakeside 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.0 °F | 32.6 °F | 1.23 in. |
| February | 19.8 °F | 36.2 °F | 0.96 in. |
| March | 25.5 °F | 45.2 °F | 1.07 in. |
| April | 31.9 °F | 55.3 °F | 1.52 in. |
| May | 39.6 °F | 65.3 °F | 1.69 in. |
| June | 46.0 °F | 71.6 °F | 2.62 in. |
| July | 50.4 °F | 82.6 °F | 1.17 in. |
| August | 48.8 °F | 82.4 °F | 0.89 in. |
| September | 41.6 °F | 71.4 °F | 1.18 in. |
| October | 32.7 °F | 55.7 °F | 1.48 in. |
| November | 26.1 °F | 41.1 °F | 1.24 in. |
| December | 20.1 °F | 32.6 °F | 1.23 in. |
| Annual | 33.5 °F | 56 °F | 16.28 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |