Palatine, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.1 °F (low) to 58.7 °F (high). Annual precipitation averages 38 Inches. Palatine is located in USDA Plant Hardiness Zone 5b. 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 | 15.4 °F | 30.8 °F | 1.99 in. |
| February | 18.1 °F | 34.5 °F | 1.96 in. |
| March | 27.5 °F | 45.6 °F | 2.25 in. |
| April | 37.7 °F | 58.2 °F | 3.76 in. |
| May | 48.6 °F | 69.4 °F | 4.61 in. |
| June | 58.5 °F | 79.6 °F | 4.49 in. |
| July | 63.8 °F | 83.9 °F | 3.73 in. |
| August | 62.4 °F | 81.7 °F | 4.09 in. |
| September | 54.4 °F | 75.0 °F | 3.31 in. |
| October | 42.5 °F | 62.1 °F | 3.24 in. |
| November | 31.4 °F | 47.9 °F | 2.4 in. |
| December | 21.4 °F | 36.1 °F | 2.13 in. |
| Annual | 40.1 °F | 58.7 °F | 37.96 in. |
| 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |