September weather forecast
Havana, Cuba

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.