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Castries vs Portland

Af Tropical rainforestCsb Warm-summer Mediterranean

Comparing Castries change · Portland change

Bottom line

Castries is the warmer of the two — about 14°C on the annual average; Castries is the wetter, with 1024 mm more rain a year, and Castries the sunnier.

Warmer Castries 14°C on the year
Wetter Castries 1024 mm more a year
Sunnier Castries 18 pp less cloud
Colder winters Portland 23°C colder nights

How the seasons compare

The differences between Castries and Portland, in everyday terms.

Summers

Summers are nearly the same

Castries: Warm
Portland: Warm

Winters

Castries has far milder winters

Castries: Stays warm
Portland: Chilly

Rain & snow

Castries is wetter

Castries: Very wet
Portland: Moderate rainfall

Sky

Castries is sunnier

Castries: Fairly sunny
Portland: Often cloudy

Month-by-month charts

Temperature

Castries is the warmer of the two — about 14°C on the annual average.

-10°10°20°30°40° JanAprJulOct CastriesPortland

Precipitation

Castries is the wetter — about 1024 mm more across the year.

PRECIPITATION (mm) 0150300 JanAprJulOct CastriesPortland

Clear skies

Castries has the clearer skies — the higher line.

0%25%50%75%100% JanAprJulOct CastriesPortland

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) Castries runs higher most of the year
JanFebMarAprMayJunJulAugSepOctNovDec
Castries272727282828282929292827
Portland9111417212428282518128
Difference-18-16-13-11-7-5-1-1-4-11-16-19
Jan – JunJanFebMarAprMayJun
Castries272727282828
Portland91114172124
Difference-18-16-13-11-7-5
Jul – DecJulAugSepOctNovDec
Castries282929292827
Portland28282518128
Difference-1-1-4-11-16-19
Avg low (°C) Castries runs higher most of the year
JanFebMarAprMayJunJulAugSepOctNovDec
Castries262525262727272828282726
Portland23471012151512852
Difference-23-23-21-20-17-15-13-13-16-19-22-24
Jan – JunJanFebMarAprMayJun
Castries262525262727
Portland23471012
Difference-23-23-21-20-17-15
Jul – DecJulAugSepOctNovDec
Castries272828282726
Portland151512852
Difference-13-13-16-19-22-24
Precipitation (mm) Castries runs higher most of the year
JanFebMarAprMayJunJulAugSepOctNovDec
Castries113766690114134216291224246243149
Portland1289310173644113143987138147
Difference+14+18+35-16-50-92-203-278-185-160-104-3
Jan – JunJanFebMarAprMayJun
Castries113766690114134
Portland12893101736441
Difference+14+18+35-16-50-92
Jul – DecJulAugSepOctNovDec
Castries216291224246243149
Portland13143987138147
Difference-203-278-185-160-104-3
Snowfall (cm)
JanFebMarAprMayJunJulAugSepOctNovDec
Castries
Portland430000000003
Difference
Jan – JunJanFebMarAprMayJun
Castries
Portland430000
Difference
Jul – DecJulAugSepOctNovDec
Castries
Portland000003
Difference
Cloud cover (%) Portland runs higher most of the year
JanFebMarAprMayJunJulAugSepOctNovDec
Castries383942495259504651514641
Portland767476757064434349637578
Difference+37+35+34+25+17+5-6-3-2+12+29+37
Jan – JunJanFebMarAprMayJun
Castries383942495259
Portland767476757064
Difference+37+35+34+25+17+5
Jul – DecJulAugSepOctNovDec
Castries504651514641
Portland434349637578
Difference-6-3-2+12+29+37
Relative humidity (%) Portland runs higher most of the year
JanFebMarAprMayJunJulAugSepOctNovDec
Castries767575767779797979797977
Portland928987848280726668798992
Difference+16+14+12+8+5+2-7-13-11+10+15
Jan – JunJanFebMarAprMayJun
Castries767575767779
Portland928987848280
Difference+16+14+12+8+5+2
Jul – DecJulAugSepOctNovDec
Castries797979797977
Portland726668798992
Difference-7-13-11+10+15

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. Castries trends → · Portland trends →

Methodology & sources

Castries

Temperature — modelled for this location from ERA5-Land reanalysis, a ~9 km global grid, because no long-record weather station is close enough to use.

Precipitation — 1991–2020 normals computed from 10 years of daily observations at LE Lamentin, a weather station, about 66 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 →