September weather forecast
Angra dos Reis, Brazil

As September arrives, the city sees a further rise in temperature and sea temperature rises to 21.2°C (70.2°F). This indicates an optimal period for snorkeling and other water activities. Despite the slight rise in temperature, daytime hours lengthen, offering a delightful climate. Rainfall begins to increase again, marking the end of the dry period. The balance between the warm days, cool nights and the recurring rains makes September a treat for nature enthusiasts.

Temperature

The transition into September is marked with an average high-temperature of a still warm 24.9°C (76.8°F), showing an insignificant shift from August's 25°C (77°F). Angra dos Reis records an average low-temperature of 18.2°C (64.8°F) throughout the month of September.

Humidity

The average relative humidity in September is 82%.

Rainfall

In Angra dos Reis, in September, it is raining for 11 days, with typically 116mm (4.57") of accumulated precipitation. Throughout the year, in Angra dos Reis, there are 165 rainfall days, and 1977mm (77.83") of precipitation is accumulated.

Sea temperature

September is the month with the coldest seawater in Angra dos Reis, with an average sea temperature of 21.2°C (70.2°F).
Note: The majority of people do not enjoy swimming in 21.2°C (70.2°F). The difficulty in controlling breathing escalates as the temperature descends from 21°C (69.8°F) to 15°C (59°F).

Daylight

In September, the average length of the day is 11h and 58min.
On the first day of September in Angra dos Reis, sunrise is at 06:06 and sunset at 17:47. On the last day of the month, sunrise is at 05:37 and sunset at 17:56 -03.

Sunshine

September through December, with an average of 4h of sunshine, are months with the least sunshine.

UV index

In Angra dos Reis, the average daily maximum UV index in September is 9. A UV Index estimate of 8 to 10 represents a very high health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: The UV index of 9 during September translates into the following guidance:
Always be careful, as unprotected skin and eyes might burn in no time. Stay in the shade and limit direct sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its strongest. Remember, however, that not all shade structures provide full sun protection. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Ward off sunburn by liberally using sunscreen with 30 SPF or more. This also diminishes the Sun's damaging radiation effects on your health. Attention! UV radiation is markedly stronger with water and sand reflections.