Castries in Summer
In summer (June, July and August), Castries sees average daytime highs around 29°C and overnight lows near 25°C, with 247 mm of rain over about 56 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Across summer, daytime highs hold fairly steady around 29°C. The sky is clear or mostly clear about 35% of the time across summer, and the air most often feels oppressive.
Summer is Castries's 3rd-best season to visit on our travel score. Castries has little temperature swing across the year, so its calendar seasons blur — the season framing matters less here than for a place with four distinct seasons. For the whole year in context, see Castries's year-round climate.
- Avg daytime high
- 29°C
- warmest season of the year
- Avg overnight low
- 25°C
- Rainfall
- 247 mm
- 56 wet days
- Avg wind
- 21 km/h
- Travel score
- 4.2
- 3rd-best season
- Months
- Jun · Jul · Aug
Temperature in Castries in Summer
Across summer, daytime highs hold fairly steady around 29°C.
A typical summer day in Castries reaches about 29°C and drops to 25°C overnight. The warmest of the three months is August, the coolest July.
How summer really feels in Castries
Once humidity and wind are folded in, summer brings about 92 days that feel above 32°C and 0 that feel at or below 0°C.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Castries weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 28° / 24° | 31 | 11.8 | 11.3 | 6.5 |
| Feb | 28° / 24° | 21 | 8.8 | 11.5 | 6.7 |
| Mar | 28° / 24° | 26 | 9.8 | 11.9 | 6.1 |
| Apr | 29° / 25° | 36 | 11.5 | 12.3 | 5.4 |
| May | 29° / 25° | 47 | 12.5 | 12.6 | 4.9 |
| Jun | 29° / 25° | 65 | 15.1 | 12.8 | 4.5 |
| Jul | 29° / 25° | 83 | 20.3 | 12.7 | 4.2 |
| Aug | 30° / 26° | 99 | 20.7 | 12.5 | 4.0 |
| Sep | 30° / 26° | 104 | 19.4 | 12.1 | 3.9 |
| Oct | 29° / 25° | 119 | 20.9 | 11.7 | 4.0 |
| Nov | 29° / 25° | 102 | 18.9 | 11.4 | 4.5 |
| Dec | 28° / 25° | 42 | 13 | 11.2 | 5.7 |
Cloud cover in Summer
The sky is clear or mostly clear about 35% of the time across summer.
Chance of precipitation in Summer
Castries gets around 247 mm of rain over 56 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 21 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 12 h 48 min in early June to 12 h 18 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.3 kWh/m².
Hazard calendar for Castries
In summer, Castries overlaps its atlantic hurricane, rainy season and dust season. The full year is below, with each hazard's peak months called out.
Castries sits in the Atlantic hurricane belt; the season peaks August–October.
Castries's rainy season runs June–November, when most of the year's rain falls.
Castries sees seasonal dust haze (June–July), heaviest in June.
Is summer a good time to visit Castries?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Castries for sightseeing.
What to pack for Castries in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Castries sees daytime highs around 29°C and nights near 25°C. Pack light clothes, rain gear and sun protection. Worth having: a windbreaker. About 56 days see rain.
Sea temperature near Castries in Summer
The nearest coast averages about 28°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 19 km away) is warmest in September at about 29°C and coldest in February near 27°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 27 | 27 | 27 | 27 | 28 | 28 | 28 | 29 | 29 | 29 | 29 | 28 |
| Comfort | Warm | Warm | Warm | Warm | Warm | Warm | Tropical | Tropical | Tropical | Tropical | Tropical | Warm |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 27 | Warm |
| Feb | 27 | Warm |
| Mar | 27 | Warm |
| Apr | 27 | Warm |
| May | 28 | Warm |
| Jun | 28 | Warm |
| Jul | 28 | Tropical |
| Aug | 29 | Tropical |
| Sep | 29 | Tropical |
| Oct | 29 | Tropical |
| Nov | 29 | Tropical |
| Dec | 28 | Warm |
UV index in Castries in Summer
Clear-sky midday UV across summer averages around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Castries peaks around March 21 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 8 (very high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 9 | 12 | 14 | 13 | 12 | 11 | 12 | 11 | 12 | 11 | 9 | 8 |
| Level | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 9 | Very high |
| Feb | 12 | Extreme |
| Mar | 14 | Extreme |
| Apr | 13 | Extreme |
| May | 12 | Extreme |
| Jun | 11 | Extreme |
| Jul | 12 | Extreme |
| Aug | 11 | Extreme |
| Sep | 12 | Extreme |
| Oct | 11 | Extreme |
| Nov | 9 | Very high |
| Dec | 8 | Very high |
Air quality in Castries in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Castries is worst in June — around 29 µg/m³ PM2.5 (moderate), about 2.9× the cleanest month (December, 10 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 10 | 14 | 12 | 16 | 19 | 29 | 25 | 21 | 15 | 18 | 13 | 10 |
| Level | Good | Moderate | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 10 | Good |
| Feb | 14 | Moderate |
| Mar | 12 | Good |
| Apr | 16 | Moderate |
| May | 19 | Moderate |
| Jun | 29 | Moderate |
| Jul | 25 | Moderate |
| Aug | 21 | Moderate |
| Sep | 15 | Moderate |
| Oct | 18 | Moderate |
| Nov | 13 | Moderate |
| Dec | 10 | Good |
Where is Castries?
Castries sits at 14.0°N, 61.0°W, 119 m above sea level, in Saint Lucia. The nearest listed city is Gros Islet, 10 km away.
Topography around Castries
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Castries.
Within 3 km, the terrain around Castries has significant variations in elevation — a maximum elevation change of 266 m around an average of 45 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 900 m; within 80 km, large variations in elevation — a maximum elevation change of 1,191 m.
The land around Castries is covered by trees (46%) and water (35%) within 3 km, water (55%) and trees (42%) within 16 km, and water (89%) within 80 km.
Saint Lucia travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type A / B / G
- 240 V · 50 Hz
- Prices
- ≈ 51% of US
- price level, 2025
- GDP per capita
- $14,746
- 2025
- Homicide rate
- 39
- per 100k, 2023
- Road deaths
- 29.8
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Castries (13.9957°, -61.0061°, elevation 119 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.