Oak Grove, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 7.2 °C (low) to 17.5 °C (high). Annual precipitation averages 1097.8 Millimeters. Oak Grove is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.4 °C | 8.6 °C | 163.58 mm |
| February | 2.6 °C | 10.7 °C | 113.28 mm |
| March | 3.9 °C | 13.4 °C | 122.94 mm |
| April | 5.7 °C | 16.3 °C | 94.49 mm |
| May | 8.7 °C | 20.3 °C | 68.07 mm |
| June | 11.1 °C | 23.2 °C | 41.4 mm |
| July | 13.3 °C | 27.5 °C | 11.18 mm |
| August | 13.4 °C | 27.8 °C | 13.97 mm |
| September | 11.1 °C | 24.6 °C | 40.64 mm |
| October | 7.6 °C | 17.8 °C | 94.74 mm |
| November | 4.5 °C | 11.7 °C | 163.07 mm |
| December | 2.2 °C | 8.1 °C | 170.43 mm |
| Annual | 7.2 °C | 17.5 °C | 1097.79 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |