United States · 30-year monthly climate averages
Based on 30 years of climate data, the most comfortable months to visit Seattle are June, July and September, when daytime temperatures are agreeable and rainfall is relatively low.
Seattle sees its warmest weather in August, when daytime highs average around 25°C, and its coolest in December (around 8°C).
Annual precipitation totals roughly 999mm — November is typically the wettest month (~160mm) and July the driest (~15mm).
A distinctly wetter period runs from November to January — worth planning around if you prefer dry days.
🟧 avg daytime high · 🟦 dashed: avg nighttime low · bars: monthly rainfall
Daily forecast highs vs the 30-year normal — last 61 days
Each bar is one day: orange above normal, blue below.
| Month | High / Low | Rainfall | Travel rating |
|---|---|---|---|
| January | 9° / 3°C | 147mm | ⚠️ Challenging |
| February | 10° / 3°C | 96mm | ⚠️ Challenging |
| March | 12° / 4°C | 106mm | 🤔 Fair |
| April | 15° / 6°C | 81mm | 👍 Good |
| May | 19° / 9°C | 48mm | 🌟 Great |
| June | 22° / 12°C | 37mm | 🌟 Great |
| July | 25° / 14°C | 15mm | 🌟 Great |
| August | 25° / 14°C | 25mm | 🌟 Great |
| September | 22° / 12°C | 41mm | 🌟 Great |
| October | 16° / 8°C | 99mm | 👍 Good |
| November | 11° / 5°C | 160mm | ⚠️ Challenging |
| December | 8° / 3°C | 145mm | ⚠️ Challenging |
January in Seattle is chilly, with average daytime highs around 9°C (48°F) and nighttime lows near 3°C (38°F). Expect roughly 147mm of precipitation spread over about 16 rainy days, and this is one of the wetter months.
🎒 What to pack — jacket or coat · long-sleeve layers · compact umbrella or rain jacket
February in Seattle is chilly, with average daytime highs around 10°C (50°F) and nighttime lows near 3°C (38°F). Expect roughly 96mm of precipitation spread over about 13 rainy days, with a moderate amount of rain.
🎒 What to pack — jacket or coat · long-sleeve layers
March in Seattle is chilly, with average daytime highs around 12°C (54°F) and nighttime lows near 4°C (40°F). Expect roughly 106mm of precipitation spread over about 14 rainy days, with a moderate amount of rain.
🎒 What to pack — jacket or coat · long-sleeve layers
April in Seattle is mild, with average daytime highs around 15°C (59°F) and nighttime lows near 6°C (43°F). Expect roughly 81mm of precipitation spread over about 12 rainy days, with a moderate amount of rain.
🎒 What to pack — light jacket · layers for cool evenings
May in Seattle is pleasantly warm, with average daytime highs around 19°C (66°F) and nighttime lows near 9°C (49°F). Expect roughly 48mm of precipitation spread over about 8 rainy days, with little rainfall.
🎒 What to pack — light layers · comfortable walking shoes
June in Seattle is pleasantly warm, with average daytime highs around 22°C (71°F) and nighttime lows near 12°C (53°F). Expect roughly 37mm of precipitation spread over about 6 rainy days, with little rainfall.
🎒 What to pack — light layers · comfortable walking shoes
July in Seattle is warm, with average daytime highs around 25°C (77°F) and nighttime lows near 14°C (57°F). Expect roughly 15mm of precipitation spread over about 3 rainy days, and rain is rare.
🎒 What to pack — light summer clothing · sunscreen and sunglasses
August in Seattle is warm, with average daytime highs around 25°C (78°F) and nighttime lows near 14°C (57°F). Expect roughly 25mm of precipitation spread over about 3 rainy days, with little rainfall.
🎒 What to pack — light summer clothing · sunscreen and sunglasses
September in Seattle is pleasantly warm, with average daytime highs around 22°C (72°F) and nighttime lows near 12°C (54°F). Expect roughly 41mm of precipitation spread over about 6 rainy days, with little rainfall.
🎒 What to pack — light layers · comfortable walking shoes
October in Seattle is mild, with average daytime highs around 16°C (60°F) and nighttime lows near 8°C (47°F). Expect roughly 99mm of precipitation spread over about 11 rainy days, with a moderate amount of rain.
🎒 What to pack — light jacket · layers for cool evenings
November in Seattle is chilly, with average daytime highs around 11°C (52°F) and nighttime lows near 5°C (41°F). Expect roughly 160mm of precipitation spread over about 16 rainy days, and this is one of the wetter months.
🎒 What to pack — jacket or coat · long-sleeve layers · compact umbrella or rain jacket
December in Seattle is chilly, with average daytime highs around 8°C (47°F) and nighttime lows near 3°C (37°F). Expect roughly 145mm of precipitation spread over about 16 rainy days, and this is one of the wetter months.
🎒 What to pack — jacket or coat · long-sleeve layers · compact umbrella or rain jacket