Annual mean 16°C · wettest around February · prevailing wind SW
Warmest
30.6 °C
Coldest
4.9 °C
Wettest
46%
Windiest
4.8 m/s
Prevailing
SW
3.6 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Portland over the whole year is 16°C. July is the hottest month, with highs of about 30°C; January is the coldest, with lows of about 1°C. Portland has no sharply defined rainy season: the chance of rain on a given day runs from 36% in October, the driest month, to 42% in February, the wettest. Winds in Portland are highest in March, averaging 3.1 m/s (11 km/h), and lightest in September, at 1.6 m/s (6 km/h). The prevailing wind is from the SW. The clearest skies in Portland come in September, when the sky is typically 28% covered; January is the cloudiest month, at 47%.
Month by month Portland climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
6°C
1°C
1°C
39%
47%
2.8 m/s
5
0
23
February
10°C
4°C
6°C
42%
45%
3.0 m/s
14
0
42
March
15°C
7°C
10°C
41%
39%
3.1 m/s
29
1
60
April
19°C
11°C
16°C
41%
35%
3.0 m/s
55
11
64
May
24°C
17°C
23°C
40%
38%
2.4 m/s
62
40
41
June
29°C
21°C
29°C
38%
29%
2.2 m/s
33
60
9
July
30°C
23°C
33°C
39%
30%
1.9 m/s
8
48
1
August
29°C
21°C
31°C
37%
32%
1.7 m/s
19
57
3
September
27°C
18°C
28°C
38%
28%
1.6 m/s
42
56
20
October
22°C
12°C
20°C
36%
31%
1.9 m/s
60
23
59
November
14°C
6°C
10°C
38%
33%
2.2 m/s
28
2
61
December
9°C
4°C
5°C
41%
44%
2.6 m/s
10
0
40
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Portland weather by season
Year round, Portland has days of about 6°C at their warmest in January, its coolest month, and 30°C in July, its warmest; the coolest hours of the day run from 1°C to 23°C through the year, and the average temperature over the year is 16°C around the clock. Rain is most likely around February and least likely around October. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Portland weather in winterDecember to February
High 8°CLow 3°CRain 41%
Winter in Portland has typical daily highs of about 8°C and lows of about 3°C, with a 41% chance of rain on a given day.
Portland weather in springMarch to May
High 19°CLow 11°CRain 41%
Spring in Portland has typical daily highs of about 19°C and lows of about 11°C, with a 41% chance of rain on a given day.
Portland weather in summerJune to August
High 30°CLow 22°CRain 38%
Summer in Portland has typical daily highs of about 30°C and lows of about 22°C, with a 38% chance of rain on a given day.
Portland weather in autumnSeptember to November
High 21°CLow 12°CRain 37%
Autumn in Portland has typical daily highs of about 21°C and lows of about 12°C, with a 37% chance of rain on a given day.
When is the rainy season in Portland?
Portland has no sharply defined rainy season: the chance of rain on a given day runs from 36% in October, the driest month, to 42% in February, the wettest.
What time of year is Portland windiest?
Winds in Portland are highest in March, averaging 3.1 m/s (11 km/h), and lightest in September, at 1.6 m/s (6 km/h). The prevailing wind is from the SW.
What is the average temperature in Portland year round?
The average temperature in Portland over the whole year is 16°C. July is the hottest month, with highs of about 30°C; January is the coldest, with lows of about 1°C.