United States · 30-year monthly climate averages
Based on 30 years of climate data, the most comfortable months to visit Portland are June, July and September, when daytime temperatures are agreeable and rainfall is relatively low.
Portland sees its warmest weather in August, when daytime highs average around 28°C, and its coolest in December (around 8°C).
Annual precipitation totals roughly 937mm — December is typically the wettest month (~147mm) and July the driest (~13mm).
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 60 days
Each bar is one day: orange above normal, blue below.
| Month | High / Low | Rainfall | Travel rating |
|---|---|---|---|
| January | 9° / 2°C | 128mm | ⚠️ Challenging |
| February | 11° / 3°C | 94mm | 🤔 Fair |
| March | 14° / 4°C | 101mm | 🤔 Fair |
| April | 17° / 7°C | 73mm | 👍 Good |
| May | 21° / 10°C | 64mm | 🌟 Great |
| June | 24° / 12°C | 41mm | 🌟 Great |
| July | 28° / 15°C | 13mm | 🌟 Great |
| August | 28° / 15°C | 14mm | 🌟 Great |
| September | 25° / 12°C | 39mm | 🌟 Great |
| October | 18° / 8°C | 87mm | 👍 Good |
| November | 12° / 5°C | 139mm | ⚠️ Challenging |
| December | 8° / 2°C | 147mm | ⚠️ Challenging |
January in Portland is chilly, with average daytime highs around 9°C (47°F) and nighttime lows near 2°C (36°F). Expect roughly 128mm of precipitation spread over about 15 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 Portland is chilly, with average daytime highs around 11°C (51°F) and nighttime lows near 3°C (37°F). Expect roughly 94mm 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 Portland is chilly, with average daytime highs around 14°C (57°F) and nighttime lows near 4°C (40°F). Expect roughly 101mm of precipitation spread over about 15 rainy days, with a moderate amount of rain.
🎒 What to pack — jacket or coat · long-sleeve layers
April in Portland is mild, with average daytime highs around 17°C (62°F) and nighttime lows near 7°C (44°F). Expect roughly 73mm of precipitation spread over about 13 rainy days, with a moderate amount of rain.
🎒 What to pack — light jacket · layers for cool evenings
May in Portland is pleasantly warm, with average daytime highs around 21°C (69°F) and nighttime lows near 10°C (49°F). Expect roughly 64mm of precipitation spread over about 10 rainy days, with a moderate amount of rain.
🎒 What to pack — light layers · comfortable walking shoes
June in Portland is pleasantly warm, with average daytime highs around 24°C (74°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
July in Portland is warm, with average daytime highs around 28°C (82°F) and nighttime lows near 15°C (58°F). Expect roughly 13mm of precipitation spread over about 2 rainy days, and rain is rare.
🎒 What to pack — light summer clothing · sunscreen and sunglasses
August in Portland is warm, with average daytime highs around 28°C (82°F) and nighttime lows near 15°C (59°F). Expect roughly 14mm of precipitation spread over about 3 rainy days, and rain is rare.
🎒 What to pack — light summer clothing · sunscreen and sunglasses
September in Portland is pleasantly warm, with average daytime highs around 25°C (77°F) and nighttime lows near 12°C (54°F). Expect roughly 39mm of precipitation spread over about 5 rainy days, with little rainfall.
🎒 What to pack — light layers · comfortable walking shoes
October in Portland is mild, with average daytime highs around 18°C (64°F) and nighttime lows near 8°C (47°F). Expect roughly 87mm of precipitation spread over about 10 rainy days, with a moderate amount of rain.
🎒 What to pack — light jacket · layers for cool evenings
November in Portland is chilly, with average daytime highs around 12°C (53°F) and nighttime lows near 5°C (41°F). Expect roughly 139mm of precipitation spread over about 15 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 Portland is chilly, with average daytime highs around 8°C (47°F) and nighttime lows near 2°C (36°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