Castries, Saint Lucia Weather
Castries hourly forecast: next 24 hours
Today's high of 84°F (29°C) is right in line with the typical September high of 86°F (30°C).
Current conditions in detail
Castries weather tomorrow (Wednesday, September 16)
Tomorrow in Castries looks patchy rain nearby, with a high of 85° and an overnight low of 80°. There is a 86% chance of rain - plan accordingly. Winds top out near 19 mph, and the UV index reaches 12 (extreme).
Castries 14-day forecast
About the weather in Castries
Castries has one of the steadier climates in our dataset. Average highs move only 2°C across the whole year - from 81°F (27°C) in January to 86°F (30°C) in September - so the practical difference between seasons here is rainfall and daylight, not warmth.
Castries weather: quick facts
- Hottest month: September - highs near 86°F (30°C)
- Coldest month: January - highs near 81°F (27°C)
- Decade extremes (2015-2024): 91°F (33°C) high · 67°F (19°C) low
- Wettest month: July (24 rainy days) · Sunniest: April (11.8 h sun/day)
- Climate type: tropical wet-and-dry
- Annual swing: 2°C between the average warmest and coolest month · day to night: 5°C
- Months averaging 30°C or hotter: 1
- Average humidity: 77%
Temperatures through the year
At its warmest, in September, Castries runs to 86°F (30°C) in the afternoon and back to 77°F (25°C) by dawn. January sits at the other end of the year: 81°F (27°C) by day, 73°F (23°C) at night. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 91°F (33°C) and the lowest daily minimum 67°F (19°C). Sunshine averages 11.2 hours a day over the year - sunnier than almost anywhere else we cover, peaking in April at 11.8 hours.
Rain, sun and snow
Days and nights are about 5°C apart on average - narrower than almost anywhere else we cover. July is the wettest month at 4.6 inches (116 mm) over 24 days; April is the driest. Between the average September and the average January lie 2°C, a narrower spread than all but 6% of the 3496 cities in our dataset.
Season by season
March through May
Through March through May, Castries sits firmly in the heat: 84°F (29°C) by day, 74°F (24°C) after dark, and rain falls on around 40 of the 90 days. Daylight is generous - around 11.7 hours of sun a day. With the moisture factored in, afternoons feel hotter than the reading suggests - the humidity and dew point converter shows why.
June through August
June through August is hot here - highs near 84°F (29°C), nights near 76°F (25°C), and rain falls on around 66 of the 90 days. Daylight is generous - around 11.4 hours of sun a day.
September through November
Through September through November, Castries sits firmly in the heat: 85°F (29°C) by day, 76°F (25°C) after dark, and rain falls on around 63 of the 90 days. Daylight is generous - around 10.8 hours of sun a day.
December through February
December through February in Castries sits firmly in the heat, with daytime highs averaging 81°F (27°C) and nights around 73°F (23°C); rain falls on around 47 of the 90 days. Daylight is generous - around 10.9 hours of sun a day.
Average temperatures in Castries by month
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 81° | 73° | 18 | 2.2 in | 10.8 h/day | 76% |
| February | 81° | 73° | 13 | 1.8 in | 11.1 h/day | 74% |
| March | 82° | 73° | 15 | 1.9 in | 11.6 h/day | 74% |
| April | 84° | 74° | 12 | 1.5 in | 11.8 h/day | 73% |
| May | 85° | 76° | 13 | 1.9 in | 11.7 h/day | 74% |
| June | 85° | 76° | 19 | 3.3 in | 11.3 h/day | 77% |
| July | 84° | 76° | 24 | 4.6 in | 11.5 h/day | 80% |
| August | 85° | 76° | 23 | 4.2 in | 11.3 h/day | 80% |
| September | 86° | 77° | 22 | 4.5 in | 11.2 h/day | 80% |
| October | 85° | 76° | 21 | 3.9 in | 10.8 h/day | 80% |
| November | 83° | 75° | 21 | 4.4 in | 10.5 h/day | 80% |
| December | 82° | 74° | 17 | 2.2 in | 10.7 h/day | 77% |