Portland climate

Name: Portland
Address: US

Portland is warmest in August, with average highs of 29 °C, and coldest in December, when nights average 2.0 °C. December is the wettest month (194 mm) and July the driest (13 mm). Figures are 1991–2020 climate normals.

Across a full year Portland averages 1,227 mm of rain, 81 days above 25 °C and 33 days below freezing.

United States · 12 m elevation · population 652,503 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month August 29 °C
Coldest month December 2.0 °C
Driest month July 13 mm
Wettest month December 194 mm
Least cloud August 35 % cloud
Hottest on record July 41 °C
Coldest on record February -15 °C

What to expectPortland through the year

Portland has a clear annual cycle: average daily highs run from 7.9 °C in December to 29 °C in August, a swing of 16 °C in mean temperature across the year.

Counted across a normal year, 81 days a year reach 25 °C, 32 of them reach 30 °C, 33 nights drop below freezing. The warmest reading in the 1991–2020 record is 41 °C, in July.

Rain is strongly seasonal. December averages 194 mm against 13 mm in July — 15 times as much. Planning around the dry months matters more here than planning around temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	8.5 °C	168 mm	77 %
February	10.5 °C	130 mm	72 %
March	13.1 °C	146 mm	74 %
April	15.8 °C	116 mm	70 %
May	19.9 °C	72 mm	65 %
June	23.0 °C	46 mm	58 %
July	28.2 °C	13 mm	36 %
August	28.8 °C	15 mm	35 %
September	25.2 °C	44 mm	42 %
October	17.7 °C	107 mm	60 %
November	11.3 °C	175 mm	74 %
December	7.9 °C	194 mm	78 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C	Days below 0 °C
January	8.5 °C	2.1 °C	4.6 °C	18.5 °C	-9.4 °C	0	0	9
February	10.5 °C	2.2 °C	5.6 °C	20.6 °C	-15.2 °C	0	0	8
March	13.1 °C	3.8 °C	7.6 °C	23.5 °C	-5.4 °C	0	0	3
April	15.8 °C	5.6 °C	9.9 °C	30.1 °C	-1.3 °C	1	0	0
May	19.9 °C	8.9 °C	13.6 °C	33.5 °C	0.9 °C	5	1	0
June	23.0 °C	11.4 °C	16.4 °C	38.7 °C	5.2 °C	9	3	0
July	28.2 °C	14.1 °C	20.3 °C	40.9 °C	8.2 °C	23	11	0
August	28.8 °C	14.5 °C	20.7 °C	40.1 °C	9.0 °C	25	12	0
September	25.2 °C	12.4 °C	17.7 °C	37.5 °C	4.9 °C	15	5	0
October	17.7 °C	8.4 °C	12.2 °C	32.0 °C	-2.4 °C	2	0	0
November	11.3 °C	4.6 °C	7.4 °C	20.6 °C	-6.6 °C	0	0	3
December	7.9 °C	2.0 °C	4.4 °C	15.1 °C	-8.2 °C	0	0	9

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	168 mm	17	9.1 h/day	77 %	86 %	15 km/h
February	130 mm	15	10 h/day	72 %	82 %	14 km/h
March	146 mm	18	12 h/day	74 %	81 %	14 km/h
April	116 mm	17	14 h/day	70 %	78 %	14 km/h
May	72 mm	12	15 h/day	65 %	73 %	13 km/h
June	46 mm	8	16 h/day	58 %	69 %	13 km/h
July	13 mm	3	15 h/day	36 %	61 %	13 km/h
August	15 mm	3	14 h/day	35 %	60 %	12 km/h
September	44 mm	6	13 h/day	42 %	67 %	12 km/h
October	107 mm	12	11 h/day	60 %	78 %	13 km/h
November	175 mm	17	9.5 h/day	74 %	86 %	14 km/h
December	194 mm	18	8.7 h/day	78 %	86 %	15 km/h

How Portland compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Portland	29 °C	2.0 °C	1,227 mm	81
Vancouver · United States	28 °C	1.7 °C	1,497 mm	76
Salem · United States	29 °C	2.1 °C	1,062 mm	83
Eugene · United States	29 °C	1.4 °C	1,287 mm	80
Tacoma · United States	25 °C	1.8 °C	1,179 mm	45

Where Portland ranks

Ranking	Position	Value
Places with the best weather in North America in September	11thof 50	92/100
Places with the best weather in North America in June	18thof 50	91/100
Places with the best weather in North America in July	24thof 50	87/100
Places with the best weather in North America in August	35thof 50	85/100
The coolest places in North America in June	44thof 50	23 °C
The driest places in North America in July	44thof 50	13 mm

Planning a trip? See the best time to visit Portland.

QuestionsCommon questions about Portland’s climate

When is the best time to visit Portland?

That depends on what you want, so the honest answer is a comparison rather than a single month. July, August, September sit closest to 20 °C on average, August is the warmest month and July the driest. The month-by-month table above has the full picture.

How hot does Portland get?

In August, the warmest month, daily highs average 29 °C. About 32 days a year pass 30 °C. The highest value in the 1991–2020 record is 41 °C.

How cold does it get in winter?

Nights average 2.0 °C in December, the coldest month. A normal year has 33 nights below freezing.

Which month is wettest in Portland?

December, averaging 194 mm over 18 days with rain. The driest month is July with 13 mm. The year as a whole averages 1,227 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Portland rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.