Seaside, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 45.4 °F (low) to 57.1 °F (high). Annual precipitation averages 75.4 Inches. 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 | 39.2 °F | 49.9 °F | 10.77 in. |
| February | 38.9 °F | 51.6 °F | 8.52 in. |
| March | 40.5 °F | 53.5 °F | 8.59 in. |
| April | 42.0 °F | 53.9 °F | 6.67 in. |
| May | 46.9 °F | 58.1 °F | 3.74 in. |
| June | 49.9 °F | 60.0 °F | 2.68 in. |
| July | 53.7 °F | 64.7 °F | 0.9 in. |
| August | 53.5 °F | 64.7 °F | 1.3 in. |
| September | 51.6 °F | 64.8 °F | 2.7 in. |
| October | 46.9 °F | 60.0 °F | 6.75 in. |
| November | 42.9 °F | 54.3 °F | 11.14 in. |
| December | 38.8 °F | 49.6 °F | 11.59 in. |
| Annual | 45.4 °F | 57.1 °F | 75.35 in. |
| 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 : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |