Seaside, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 7.5 °C (low) to 14 °C (high). Annual precipitation averages 1913.9 Millimeters. Seaside is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4 °C | 9.9 °C | 273.56 mm |
| February | 3.8 °C | 10.9 °C | 216.41 mm |
| March | 4.7 °C | 11.9 °C | 218.19 mm |
| April | 5.6 °C | 12.2 °C | 169.42 mm |
| May | 8.3 °C | 14.5 °C | 95 mm |
| June | 9.9 °C | 15.6 °C | 68.07 mm |
| July | 12.1 °C | 18.2 °C | 22.86 mm |
| August | 11.9 °C | 18.2 °C | 33.02 mm |
| September | 10.9 °C | 18.2 °C | 68.58 mm |
| October | 8.3 °C | 15.6 °C | 171.45 mm |
| November | 6.1 °C | 12.4 °C | 282.96 mm |
| December | 3.8 °C | 9.8 °C | 294.39 mm |
| Annual | 7.5 °C | 14 °C | 1913.91 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 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 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |