Carolina Weather in September

Thinking of visiting Carolina in September? Expect very high temperatures reaching 31°C (88°F) during the day, dropping to 25°C (77°F) at night, and be prepared for the wettest month of the year.

Rainfall in Carolina in September

The heaviest rainfall of the year happens this month, with frequent showers. A poncho is your best bet to stay dry. This month experiences about 18 days of rain according to historical data, averaging 167 mm (6.6 in). This is a wet month with frequent and often heavy showers. Both the number of rain days and the total rainfall are high.

Temperature in Carolina in September

Carolina in September gets highs of 31°C (88°F) during the day and drops to 25°C (77°F) at night. Mornings and evenings are often more comfortable than the peak afternoon hours. Nights stay warm at around 25°C (77°F), so light bedding and good ventilation are worth thinking about.

Sunshine in Carolina in September

The city usually sees around 236 hours of sunlight, indicating many sunny days — a great month for sightseeing.

Wind Speed in Carolina in September

Average wind speeds reach 3 m/s (6 knots) in September, creating light breezes that feel pleasant throughout the day. Some days are calmer, while others bring slightly more active breezes.

Average water temperature in September

The water is 29°C (84°F) — very warm by most standards. Comfortable to swim in, but not particularly refreshing if you're looking to cool off.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. January, February, March, April and December typically offer the best weather for Carolina.

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Puerto Rico, check out our Carolina's climate page.

Carolina Temperature in September

Min Temperature 25°C (77°F)  

Max Temperature 31°C (88°F)  

Water Temperature 29°C (84°F) *  

Chance of Rain 60%  

Precipitation 167 mm (6.6 in)  

Rainy days 18 days  

Humidity 76% *  

Windspeed 3 m/s (6 knots) *  

Sunshine 236 hours *  

Percentage Sunshine 64% *  

* Data from: San Juan, Puerto Rico (7 KM, 4 Miles).

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Carolina 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

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

‹ January February March April May June July August September October November December ›

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

‹ Select year to compare to 2026 2025 2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 ›

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

‹ January February March April May June July August September October November December ›

Historical weather for Carolina in September

Browse day-by-day weather records for Carolina spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Historical weather Temperatures Precipitation

‹ 2026 2025 2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 ›

‹ January February March April May June July August September October November December ›

Carolina historical weather extremes in September

Based on 49 years of weather observations in Carolina between 1976 and 2025, these are the recorded extremes.

• On September 29, 2011, temperatures climbed to 36°C (97°F), marking the warmest September day on record.
• The lowest daytime temperature in September was 24°C (75°F), recorded on September 13, 1985.
• Carolina registered its coldest September night on September 9, 1988, with temperatures dropping to 21°C (70°F).

What to Wear in Carolina 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. Expect water temperatures of around 29°C (84°F), which is ideal for taking a refreshing dip. Bring swimwear and consider packing a towel for drying off. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Carolina in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

8/10

Cycling

7/10

Walking

7/10

Camping

7/10

Outdoor sports

7/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Puerto Rico, check out our Carolina's climate page.

More climate data for Carolina

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full Carolina climate overview or explore weather in Puerto Rico.