Castries Temperature by Month
The average annual maximum temperature in Castries, Castries, Saint Lucia is 30°C (86°F), with little variation between seasons. This page covers monthly averages, day-night differences, and how Castries compares to cities worldwide.
Castries Monthly Temperatures
Castries enjoys a stable climate with temperatures staying pretty much the same throughout the year. Maximum daytime temperatures range from a comfortable 29°C (84°F) in February to a very warm 31°C (88°F) in September. Nights are consistently cool, with lows between 26°C (79°F) and 24°C (75°F).
The chart below illustrates the average maximum day and minimum night temperatures in Castries by month:
From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. September, the warmest month, averages 238 hours of sunshine.
The chart below shows the average temperature throughout the year:
Daily Historical Temperatures
50-year average (1976-2025)
Average high and low temperatures for each day of the month based on long-term records.
Average temperatures in July
Historical Castries Temperatures: 1976-2026
Browse day-by-day temperature records for Castries spanning 51 years. Select any month and year to see actual high and low temperatures recorded on each day.
Temperature: Castries vs Saint Lucia
The map below shows the annual temperature across Saint Lucia. You can also select individual months if you want to compare a specific time of year.
very warm
warm
pleasant
moderate
cold
very cold
Castries vs World: Temperature Compared
Castries's average annual maximum temperature is 30°C (86°F). To put that in context, here's how it compares to a few well-known destinations:
Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.
Queenstown, New Zealand averages 10°C (50°F) annually — remember seasons are flipped, so its coldest months fall in June and July.
Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters — and seasons reversed compared to Europe.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
What Does the Temperature Feel Like in Castries?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In Castries, February is the coolest month, with average highs of 29°C (84°F) and humidity around 79% — considered high. In September, the warmest month, temperatures average 31°C (88°F) with 81% humidity — conditions that feel very high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Seasonal temperature shifts influence more than just how warm it feels — they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.
Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Castries this rarely lasts long on the ground.
For more on Castries's weather — including monthly rainfall, sunshine hours, and humidity — visit our Castries climate page.
