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Seoul vs Portland

Cwa Monsoon-influenced humid subtropicalCsb Warm-summer Mediterranean

Comparing Seoul change · Portland change

Bottom line

Seoul and Portland have nearly identical year-round temperatures; Seoul is the wetter, with 569 mm more rain a year, and Seoul the sunnier.

Year-round temp About the same within 1°C on the year
Wetter Seoul 569 mm more a year
Sunnier Seoul 9 pp less cloud
Colder winters Seoul 9°C colder nights

How the seasons compare

The differences between Seoul and Portland, in everyday terms.

Summers

Seoul has hotter summers

Seoul: Warm
Portland: Warm

Winters

Portland has much milder winters

Seoul: Cold
Portland: Chilly

Rain & snow

Seoul is wetter

Seoul: Wet
Portland: Moderate rainfall

Sky

Seoul is sunnier

Seoul: Partly cloudy
Portland: Often cloudy

Month-by-month charts

Temperature

Seoul and Portland run remarkably close all year.

-20°20°40° JanAprJulOct SeoulPortland

Precipitation

Seoul is the wetter — about 569 mm more across the year.

PRECIPITATION (mm) 0225450 JanAprJulOct SeoulPortland

Clear skies

Seoul has the clearer skies — the higher line.

0%25%50%75%100% JanAprJulOct SeoulPortland

Exact monthly numbers

Tap a metric to open its full table. Desktop shows all twelve months; on a phone each metric splits into Jan–Jun and Jul–Dec.

Avg high (°C) Varies through the year
JanFebMarAprMayJunJulAugSepOctNovDec
Seoul251118242829302620124
Portland9111417212428282518128
Difference+7+6+3-1-3-4-1-2-1-2+4
Jan – JunJanFebMarAprMayJun
Seoul2511182428
Portland91114172124
Difference+7+6+3-1-3-4
Jul – DecJulAugSepOctNovDec
Seoul29302620124
Portland28282518128
Difference-1-2-1-2+4
Avg low (°C) Varies through the year
JanFebMarAprMayJunJulAugSepOctNovDec
Seoul-6-4171318222317103-4
Portland23471012151512852
Difference+9+7+3-1-3-6-7-8-5-2+2+6
Jan – JunJanFebMarAprMayJun
Seoul-6-4171318
Portland23471012
Difference+9+7+3-1-3-6
Jul – DecJulAugSepOctNovDec
Seoul222317103-4
Portland151512852
Difference-7-8-5-2+2+6
Precipitation (mm) Varies through the year
JanFebMarAprMayJunJulAugSepOctNovDec
Seoul21324175104138440362154585625
Portland1289310173644113143987138147
Difference+106+61+59-2-40-96-427-349-116+29+83+122
Jan – JunJanFebMarAprMayJun
Seoul21324175104138
Portland12893101736441
Difference+106+61+59-2-40-96
Jul – DecJulAugSepOctNovDec
Seoul440362154585625
Portland13143987138147
Difference-427-349-116+29+83+122
Snowfall (cm)
JanFebMarAprMayJunJulAugSepOctNovDec
Seoul
Portland430000000003
Difference
Jan – JunJanFebMarAprMayJun
Seoul
Portland430000
Difference
Jul – DecJulAugSepOctNovDec
Seoul
Portland000003
Difference
Cloud cover (%) Varies through the year
JanFebMarAprMayJunJulAugSepOctNovDec
Seoul515052555867756556465251
Portland767476757064434349637578
Difference+24+24+23+20+11-3-31-21-7+17+24+26
Jan – JunJanFebMarAprMayJun
Seoul515052555867
Portland767476757064
Difference+24+24+23+20+11-3
Jul – DecJulAugSepOctNovDec
Seoul756556465251
Portland434349637578
Difference-31-21-7+17+24+26
Relative humidity (%) Portland runs higher most of the year
JanFebMarAprMayJunJulAugSepOctNovDec
Seoul767474747578858479757677
Portland928987848280726668798992
Difference+16+15+13+10+7+3-13-18-11+4+14+16
Jan – JunJanFebMarAprMayJun
Seoul767474747578
Portland928987848280
Difference+16+15+13+10+7+3
Jul – DecJulAugSepOctNovDec
Seoul858479757677
Portland726668798992
Difference-13-18-11+4+14+16

How both climates are changing

Both cities are warming. Each city has its own warming trend; see its trends page for the year-by-year detail. Seoul trends → · Portland trends →

Methodology & sources

Seoul

Temperature & precipitation — 1991–2020 normals computed from 30 years of daily observations at Seoul City, a weather station, about 1 km from the city centre. The underlying daily records come from NOAA's global station network.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

Portland

Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Portland Intl AP (NOAA GHCN station USW00024229), about 10 km from the city centre.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →