September weather forecastHavana, Cuba

September
Weather in September
September in Havana welcomes a slight retreat from the scorching summer months. Rainfall begins to climb once again, representing one of the wettest months of the year with 144mm (5.67"). The reduced temperature counts allow for more leisurely outdoor explorations. Even though the city brims under invigorating showers, the daylight hours and sunshine hours continue to remain generous. A moderate sea temperature makes September a delightful time for travelers aiming to enjoy the city's famous beaches.Temperature
The start of September in Havana marks an average high-temperature of a still hot 31°C (87.8°F), hardly distinguishable from the conditions in August. During September, the nighttime temperature averages of 23.8°C (74.8°F).Heat index
For most parts of September, the heat index is appraised at a blistering 41°C (105.8°F). Adopt heightened safety measures, heat cramps and heat exhaustion may occur. Sustained activity might cause heatstroke.Heat index guidelines indicate values are for light wind scenarios and shaded regions. An exposure to direct sunlight may lift the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', unifies temperature and humidity readings to offer a comprehensive feel of warmth. One's perception of temperature is subjective, varying based on their activity and individual heat perception, influenced by factors like wind, clothing, and metabolic variations. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.
The body's inherent cooling system operates through perspiration, wherein evaporating sweat offsets excessive heat. When the air contains significant moisture, the efficiency of the evaporation process decreases, preventing the body from cooling down effectively and creating a feeling of overheating. Potential thermal conditions emerge as the body's heat gain outpaces its cooling mechanisms.
Humidity
In Havana, the average relative humidity in September is 79%.Rainfall
In Havana, Cuba, during September, the rain falls for 10 days and regularly aggregates up to 144mm (5.67") of precipitation. Throughout the year, there are 80 rainfall days, and 1189mm (46.81") of precipitation is accumulated.Sea temperature
In Havana, the average seawater temperature in September is 29.4°C (84.9°F).Note: In water temperatures ranging between 25°C (77°F) and 29°C (84.2°F), activities such as swimming and diving become highly pleasurable for long durations.
Daylight
In September, the average length of the day in Havana is 12h and 16min.On the first day of the month, sunrise is at 07:11 and sunset at 19:46. On the last day of September, sunrise is at 07:20 and sunset at 19:17 CDT.
Sunshine
With an average of 10h of sunshine, September has the most sunshine of the year in Havana.UV index
The average daily maximum UV index in September in Havana, Cuba, is 11. A UV Index of 11, and more, symbolizes an excessive health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index, 11 in September, converts into the following recommendations:
Put into action all crucial precautions. Defense against sun damage is a must. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. After a swim or an outdoor workout, generously apply and regularly reapply a sunscreen with at least SPF 30, even if the day is cloudy. Take note! Sand and water reflections strengthen the Sun's UV exposure.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Havana, Cuba
- Average high temperature in September: 31°C
The warmest month (with the highest average high temperature) is August (31.6°C).
The month with the lowest average high temperature is January (25.8°C).
- Average low temperature in September: 23.8°C
The month with the highest average low temperature is August (24.1°C).
The coldest months (with the lowest average low temperature) are January and February (18.6°C).
Average humidity in September
Havana, Cuba
- Average humidity in September: 79%
The month with the highest relative humidity is October (80%).
The month with the lowest relative humidity is April (72%).
Average rainfall in September
Havana, Cuba
- Average rainfall in September: 144.4mm
The wettest month (with the highest rainfall) is June (182.3mm).
The driest month (with the least rainfall) is March (46.2mm).
Average rainfall days in September
Havana, Cuba
- Average rainfall days in September: 10 days
The month with the highest number of rainy days is October (11 days).
The months with the least rainy days are March and April (3 days).
Average sea temperature in September
Havana, Cuba
- Average sea temperature in September: 29.4°C
The best month for swimming (with the highest average sea temperature) is August (30.2°C).
The coldest month (with the lowest average sea temperature) is January (24.7°C).
Average daylight in September /
Average sunshine in September
Havana, Cuba
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 13h and 30min).
The month with the shortest days is December (Average daylight: 10h and 42min).
- Average sunshine in September: 10h
The month with the most sunshine is September (Average sunshine: 10h).
The months with the least sunshine are January, February, November and December (Average sunshine: 7h).
Average UV index in September
Havana, Cuba
- Average UV index in September: 11
The months with the highest UV index are April, May and June (UV index 12).
The months with the lowest UV index are January and December (UV index 6).





