Portland, Oregon Weather
Rufous Hummingbirds Arrive. Day 76 of spring. Read this microseason across nine climate regions →
Portland weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Light Drizzle20%0.01″71°55°—
- ThursdayJun 4Overcast——69°50°-2°
- FridayJun 5Light Drizzle17%—61°49°-8°
- SaturdayJun 6Light Showers70%—59°45°-2°
- SundayJun 7Overcast——72°43°+13°
- MondayJun 8Light Drizzle47%0.01″61°52°-11°
- TuesdayJun 9Overcast37%—65°51°+4°
PM2.5 at 15.5 µg/m³, PM10 at 21.8 µg/m³ — typical background levels with no transport signature. AQI flat over the last 6 hours (within ±4 points).
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 32. Overcast through the UV peak window (cloud cover ~94%) — afternoon ozone should stay flat.
- Present
- AQI 32
- UV peak
- 4.0 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 9
PM × Wind × Precip
PM2.5 at 15.5 µg/m³, PM10 at 21.8 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.71
- Wind
- light
- Recent rain
- 1h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
The higher the clouds, the finer the weather.
- Moonrise
- 6:30 AM
- Moonset
- 2:53 PM
- In sign
- ♑︎ Capricorn
Rufous Hummingbirds Arrive
Portland at a glance
- Today vs. normal: 5°F below the seasonal normal for this latitude
- Last frost: May 19 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 3, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | — | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
August brings Portland's warmest temperatures (~70°F mean), while December delivers the coldest (~42°F). December also marks the wettest period with 7.3 inches of rainfall, contrasting sharply with July's dry 0.4 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 42° | 6.4″ | 14 |
| February | 45° | 4.7″ | 10 |
| March | 48° | 4.8″ | 12 |
| April | 53° | 3.6″ | 11 |
| May | 59° | 2.6″ | 8 |
| June | 63° | 1.5″ | 5 |
| July | 69° | 0.4″ | 2 |
| August | 70° | 0.5″ | 2 |
| September | 65° | 1.6″ | 4 |
| October | 55° | 4.0″ | 9 |
| November | 47° | 6.6″ | 13 |
| December | 42° | 7.3″ | 14 |
Regional context
Portland belongs to the warm-summer Mediterranean climate region, sharing similar temperature ranges, seasonal patterns, and growing conditions with other nearby cities in this zone.
Similar climates: Eugene, OR, Salem, OR, Medford, OR, Bend, OR, Gresham, OR.
Naturalist notes
Late May brings the first blooms of Oregon grape, their bright yellow flower clusters emerging after the final spring frosts.
American robins begin their second nesting cycle in June, taking advantage of Portland's lengthening daylight hours.
Frequently asked
- When does it freeze in Portland?
- Portland's last spring frost typically occurs around mid-May, while the first fall frost returns around mid-October.
- What is the rainy season in Portland?
- December stands as the wettest month, averaging about 7.3 inches of rain, contributing to the city's annual total of roughly 44 inches.
- What is the warmest month in Portland?
- August typically records the warmest temperatures, averaging about 70°F.
- What is the coldest month in Portland?
- December typically brings the coldest weather, averaging about 42°F.
- When can I start a vegetable garden in Portland?
- Cool-season crops like peas and lettuce can be planted around the last spring frost in mid-May, while warm-season crops such as tomatoes and peppers should wait 1–2 weeks after.
- How many rainy days does Portland get?
- Portland experiences about 102 rainy days per year on average.
- What hardiness zone is Portland?
- Portland's USDA hardiness zone depends on its lowest average winter temperature; the USDA's online lookup tool can provide the current zone designation using the city ZIP code.
Climate
Portland, Oregon experiences a warm-summer Mediterranean climate. January temperatures typically hover near 42°F, while July averages 69°F — creating a 27°F seasonal swing.
Annual precipitation totals about 44 inches, falling across roughly 102 rainy days throughout the year.
Geography drives Portland's weather patterns through its latitude (45.5°N), proximity to large water bodies, and elevation. These factors determine what grows in the region, when frost occurs, and the daily weather patterns.