September weather forecast
Cacheu, Guinea-Bissau

Departing from the extremely wet conditions of August, September brings about a particular change in Cacheu. Here, the city sees the end of the peak rainy season, making a progressive shift towards the dry season. With sea temperatures averaging 28.5°C (83.3°F) and the hours of sunshine increasing, the weather begins to regain its dry characteristics. Humidity drops slightly, while wind speeds begin to spring back up. Though September still sees considerable rainfall, it is less intense than in the preceding months.

Temperature

As Cacheu welcomes September, the average high-temperature stabilizes at a hot 30.9°C (87.6°F), showing little deviation from August's 29.8°C (85.6°F). Cacheu temperatures generally rest at a low of 24.7°C (76.5°F) during the September nights.

Heat index

September's average heat index is computed to be a blistering 41°C (105.8°F). Exercise extra preventive actions, heat cramps and heat exhaustion are plausible. Continuous activity could result in heatstroke.
Consider that heat index readings are for situations in the shade and light wind. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', shows a temperature sensation when both heat and moisture conditions are combined. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. When you're directly under the sun's rays, remember that the heat index may surge by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children often do not understand the need to rest and hydrate. Thirst is a late manifestation of dehydration - therefore, it is essential to stay hydrated, particularly during prolonged physical activities.
The evaporation of sweat is a natural cooling mechanism of the human body, facilitated by perspiration. A surge in relative humidity can disrupt the body's normal cooling function by slowing evaporation, hence reducing the rate at which the body cools and intensifying the perception of heat. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.

Humidity

The average relative humidity in September is 80%.

Rainfall

In Cacheu, during September, the rain falls for 20.5 days and regularly aggregates up to 133mm (5.24") of precipitation. Throughout the year, there are 103.1 rainfall days, and 677mm (26.65") of precipitation is accumulated.

Sea temperature

In Cacheu, in September, the average water temperature is 28.5°C (83.3°F).
Note: Surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as excellent and extremely agreeable for enduring enjoyment in water activities.

Daylight

In Cacheu, Guinea-Bissau, the average length of the day in September is 12h and 11min.
On the first day of the month, sunrise is at 06:54 and sunset at 19:14. On the last day of September, sunrise is at 06:53 and sunset at 18:55 GMT.

Sunshine

In September, the average sunshine in Cacheu, Guinea-Bissau, is 7.3h.

UV index

The months with the highest UV index in Cacheu are January through June, September through December, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for average individuals.
Note: The daily maximum UV index of 7 in September interprets into the following advice:
Uphold preventive measures and conform to sun safety guidelines. Defending against skin and eye harm is crucial. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. During bright days, sunglasses that offer UVA and UVB defense are recommended. Warning! Sand and water reflections boost the intensity of UV exposure.