Castries Weather in September
September in Castries sees daytime temperatures around 31°C (88°F) and lows of 26°C (79°F) at night. With around 122 mm (4.8 in) of rainfall expected, it's worth packing a rain jacket.
Rainfall in Castries in September
Historically, approximately 24 days this month are expected to have rain, averaging 122 mm (4.8 in). This month brings frequent, heavy showers. Both the number of wet days and the rainfall totals are on the high side.
Temperature in Castries in September
Daytime highs in Castries in September reach 31°C (88°F), with nights around 26°C (79°F). Indoor breaks or shaded spots can make the warmer part of the day much more comfortable. Nights stay warm at around 26°C (79°F), so light bedding and good ventilation are worth thinking about.
Sunshine in Castries in September
The city usually sees around 238 hours of sunlight, indicating many sunny days — a great month for sightseeing.If you prefer dry days with pleasant temperatures, September may not be the ideal month to visit Castries. Our weather planner can help you explore destinations with more pleasant weather conditions.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Saint Lucia, check out our Castries's climate page.
Castries Temperature in September
Min Temperature
26°C (79°F)
Max Temperature
31°C (88°F)
Chance of Rain
81%
Precipitation
122 mm (4.8 in)
Rainy days
24 days
Humidity
81% *
Sunshine
238 hours *
Percentage Sunshine
*
Daily Historical Temperatures
49-year average (1976-2025)
Based on our historical records, temperatures in Castries typically stay consistent throughout September, with daily highs averaging around 31°C (88°F). Nights are warm, with lows around 25°C (77°F).
Average temperatures in September
Historical weather for Castries in September
Browse day-by-day weather records for Castries spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Castries historical weather extremes in September
According to our 35 years of weather records for Castries, the following extremes were recorded between 1990 and 2025.
- The warmest day in September was on September 3, 2003, with a maximum of 34°C (93°F).
- Castries experienced its chilliest September day on September 18, 2008, reaching only 27°C (81°F).
- Nighttime temperatures dropped to 18°C (64°F) on September 11, 2011, marking the coldest September night on record.
Best Places in Saint Lucia in September
Find out more about the weather in Saint Lucia and which places have the best travel conditions in this month. See all of Saint Lucia in September →
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What to Wear in Castries in September
Warm temperatures in September make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Prepare for significant rainfall with proper waterproof clothing and shoes. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in Castries in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Saint Lucia, check out our Castries's climate page.
Temperature Rainfall Sunshine Humidity
See the full Castries climate overview or explore weather in Saint Lucia.
