Loiza Weather in September
Thinking of visiting Loiza in September? Expect very high temperatures reaching 31°C (88°F) during the day, dropping to 26°C (79°F) at night, and be prepared for the wettest month of the year.
Rainfall in Loiza in September
The month is marked by heavy rainfall, often coming down in intense bursts. Make sure to have a poncho to stay dry. You can typically expect 18 days of rain this month, averaging around 156 mm (6.1 in). This month brings frequent, heavy showers. Both the number of wet days and the rainfall totals are on the high side.
Temperature in Loiza in September
Expect highs of 31°C (88°F) in Loiza in September, with nights dropping to around 26°C (79°F). For most visitors, the main thing to prepare for is the heat during the day. With lows around 26°C (79°F), the nights are warm enough that a sheet is usually all you need for bedding. Expect some days to be hotter than these averages. Stay cool by wearing light clothing and drinking plenty of water throughout the day.
Sunshine in Loiza in September
Expect a lot of sunshine this month, with about 236 hours of sun. These sunny conditions add to the overall experience.
Wind Speed in Loiza in September
September has wind speeds averaging 3 m/s (6 knots). You can expect comfortable light winds that steadily move flags and feel mild throughout the day. Since this is an average, daily conditions vary from gentle winds to more active breezes.
Average water temperature in September
The water reaches 29°C (84°F) this month. It's on the warm side, which suits people who prefer that, but don't expect a cooling dip if the air temperature is also high.September in Loiza can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Puerto Rico, check out our Loiza's climate page.
Loiza Temperature in September
Min Temperature
26°C (79°F)
Max Temperature
31°C (88°F)
Water Temperature
29°C (84°F) *
Chance of Rain
60%
Precipitation
156 mm (6.1 in)
Rainy days
18 days
Humidity
76% *
Windspeed
3 m/s (6 knots) *
Sunshine
236 hours *
Percentage Sunshine
64% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Loiza typically stay consistent throughout September, with daily highs averaging around 31°C (88°F). Nights are warm, with lows around 26°C (79°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Loiza in September
Browse day-by-day weather records for Loiza spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Loiza historical weather extremes in September
Based on 49 years of weather observations in Loiza between 1976 and 2025, these are the recorded extremes.
- The hottest September day on record in Loiza reached 36°C (97°F) (September 29, 2011).
- On September 13, 1985, Loiza saw its coldest September day with temperatures maxing out at 25°C (77°F).
- The lowest overnight temperature recorded in September was 21°C (70°F) (September 9, 1988).
Best Places in Puerto Rico in September
Find out more about the weather in Puerto Rico and which places have the best travel conditions in this month. See all of Puerto Rico in September →
perfect weather
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What to Wear in Loiza in September
Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Also bring a poncho, it will rain a lot! Waterproof everything you can. The water temperature sits at about 29°C (84°F), making it perfect for swimming and water activities. Don't forget to pack your favorite swimwear and perhaps some snorkel gear. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in Loiza 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 Puerto Rico, check out our Loiza's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Loiza climate overview or explore weather in Puerto Rico.
