September weather forecast
Bolama, Guinea-Bissau

September ushers in an easing of rain with a drop down to 132mm (5.2"). During this period, Bolama begins to transition from the wet period back to the dry season. With less cloud coverage than the previous months, daylight hours begin to increase again. Sunshine takes a front seat again, relieving the city from heavy clouds and constant downpours. The weather during this month allows visitors to begin exploring outdoor activities as the rains recede, marking the beginning of the drier months ahead.

Temperature

The commencement of September brings an average high-temperature of a hot 30.5°C (86.9°F), marking an inconsequential divergence from August. September nights experience a consistent temperature drop to a warm 25°C (77°F).

Heat index

The heat index value for September is evaluated at a blistering 40°C (104°F). Use additional protective measures, heat cramps and heat exhaustion are possible outcomes. Continuous activity might lead to heatstroke.
Heat index determinations are made taking into account the shade and light air movements. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', provides an understanding of perceived warmth by combining temperature and relative humidity. Elements of metabolic variation, physical activity, and clothing contribute to the effect of temperature on an individual. Understand that direct sun rays can influence the weather's impact, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
In high temperatures, perspiration kicks in, allowing the human body to cool down through the evaporation of sweat. Under conditions of high relative humidity, the rate of evaporation decreases. This results in the body retaining more heat than under conditions of dry air. The body is at risk of dehydration and related complications when it fails to shed excessive heat.

Humidity

The average relative humidity in September in Bolama is 81%.

Rainfall

In Bolama, Guinea-Bissau, in September, it is raining for 20.7 days, with typically 132mm (5.2") of accumulated precipitation. In Bolama, during the entire year, the rain falls for 107.5 days and collects up to 726mm (28.58") of precipitation.

Sea temperature

In Bolama, in September, the average water temperature is 27.8°C (82°F).
Note: Water temperatures in the range of 25°C (77°F) to 29°C (84.2°F) are warm and delightful, ensuring comfort during water activities over extended periods.

Daylight

In September, the average length of the day in Bolama is 12h and 11min.
On the first day of September in Bolama, Guinea-Bissau, sunrise is at 06:51 and sunset at 19:11. On the last day of the month, sunrise is at 06:50 and sunset at 18:52 GMT.

Sunshine

In September, the average sunshine is 7.5h.

UV index

January through December, with an average maximum UV index of 7, are months with the highest UV index. January through December, with an average maximum UV index of 7, are months with the lowest UV index. A UV Index value of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: In September, a daily UV index of 7 turns into the following recommendations:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. Be aware that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. and try to reduce direct sun exposure during this period as much as possible. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Caution! Sand and water reflections can notably increase the UV radiation intensity.