Castries climate

Name: Castries
Address: LC

Castries is warmest in September, with average highs of 29 °C, and coldest in February, when nights average 23 °C. October is the wettest month (119 mm) and February the driest (25 mm). Figures are 1991–2020 climate normals.

Across a full year Castries averages 813 mm of rain and 365 days above 25 °C.

Saint Lucia · population 20,000 · 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 September 29 °C
Coldest month February 23 °C
Driest month February 25 mm
Wettest month October 119 mm
Least cloud January 37 % cloud
Hottest on record September 32 °C
Coldest on record February 20 °C
Warmest sea September 29 °C

What to expectCastries through the year

Castries changes little through the year. Average daily highs stay between 27 and 29 °C, so no month stands out as a season in the way it would further from the equator.

Counted across a normal year, 365 days a year reach 25 °C, 19 of them reach 30 °C. The warmest reading in the 1991–2020 record is 32 °C, in September.

Rain is strongly seasonal. October averages 119 mm against 25 mm in February — 4.7 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Castries is warmest in September at 29 °C and coldest in February at 27 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	27.0 °C	36 mm	37 %
February	27.4 °C	25 mm	38 %
March	27.9 °C	30 mm	44 %
April	28.5 °C	39 mm	53 %
May	29.1 °C	51 mm	59 %
June	29.0 °C	68 mm	63 %
July	28.8 °C	89 mm	54 %
August	29.0 °C	101 mm	55 %
September	29.2 °C	105 mm	62 %
October	28.7 °C	119 mm	61 %
November	28.0 °C	103 mm	53 %
December	27.5 °C	46 mm	42 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	27.0 °C	23.5 °C	25.0 °C	29.1 °C	20.4 °C	31	0
February	27.4 °C	23.3 °C	25.0 °C	30.7 °C	20.2 °C	28	0
March	27.9 °C	23.5 °C	25.3 °C	30.9 °C	20.9 °C	31	0
April	28.5 °C	24.1 °C	26.0 °C	30.9 °C	21.4 °C	30	1
May	29.1 °C	24.8 °C	26.7 °C	31.3 °C	22.6 °C	31	4
June	29.0 °C	25.1 °C	26.8 °C	30.9 °C	22.7 °C	30	2
July	28.8 °C	24.9 °C	26.6 °C	30.6 °C	23.4 °C	31	1
August	29.0 °C	25.1 °C	26.8 °C	31.4 °C	23.0 °C	31	3
September	29.2 °C	25.2 °C	27.0 °C	32.0 °C	22.9 °C	30	6
October	28.7 °C	25.0 °C	26.6 °C	31.4 °C	22.2 °C	31	2
November	28.0 °C	24.6 °C	26.1 °C	30.0 °C	22.6 °C	30	0
December	27.5 °C	24.1 °C	25.5 °C	29.6 °C	20.9 °C	31	0

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	36 mm	12	11 h/day	37 %	74 %	25 km/h	27.1 °C
February	25 mm	9	12 h/day	38 %	72 %	25 km/h	26.7 °C
March	30 mm	10	12 h/day	44 %	71 %	24 km/h	26.8 °C
April	39 mm	11	12 h/day	53 %	73 %	23 km/h	27.2 °C
May	51 mm	12	13 h/day	59 %	74 %	23 km/h	27.7 °C
June	68 mm	16	13 h/day	63 %	76 %	26 km/h	27.8 °C
July	89 mm	20	13 h/day	54 %	78 %	25 km/h	28.0 °C
August	101 mm	20	13 h/day	55 %	79 %	22 km/h	28.7 °C
September	105 mm	19	12 h/day	62 %	79 %	20 km/h	29.1 °C
October	119 mm	20	12 h/day	61 %	80 %	20 km/h	29.0 °C
November	103 mm	19	11 h/day	53 %	80 %	21 km/h	28.5 °C
December	46 mm	13	11 h/day	42 %	76 %	24 km/h	27.8 °C

How Castries 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
Castries	29 °C	23 °C	813 mm	365
Fort-de-France · Martinique	29 °C	24 °C	1,000 mm	365
Kingstown · Saint Vincent and the Grenadines	29 °C	25 °C	1,022 mm	365
Roseau · Dominica	28 °C	24 °C	818 mm	359
Bridgetown · Barbados	29 °C	24 °C	929 mm	365
Saint George's · Grenada	28 °C	25 °C	1,133 mm	365
Basse-Terre · Guadeloupe	30 °C	24 °C	816 mm	364

Where Castries ranks

Ranking	Position	Value
The warmest places in North America in December	40thof 50	27 °C
The warmest places in North America in January	40thof 50	27 °C
The warmest places in North America in November	50thof 50	28 °C

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

QuestionsCommon questions about Castries’s climate

When is the best time to visit Castries?

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

How hot does Castries get?

In September, the warmest month, daily highs average 29 °C. About 19 days a year pass 30 °C. The highest value in the 1991–2020 record is 32 °C.

How cold does it get in winter?

Nights average 23 °C in February, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Castries?

October, averaging 119 mm over 20 days with rain. The driest month is February with 25 mm. The year as a whole averages 813 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 Castries 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.