September weather forecastBoe, Guinea-Bissau
September
Weather in September
The arrival of September signals a noticeable decline in rainfall, reducing to 168mm (6.61"), signifying the gradual retreat of the wet season. Despite the reduced rainfall, high humidity levels persist at 85%. Temperature readings exhibit mild fluctuations, with the maximum temperature rising to 30.9°C (87.6°F) while the minimum temperature subtly decreases to 23.6°C (74.5°F). Consequently, the city sees a slight increase in sunshine hours, yet it remains far from matching the averages viewed at the start of the year.Temperature
The transition into September reveals an average high-temperature of a tropical 30.9°C (87.6°F), mirroring a close resemblance to August. September witnesses an average nighttime temperature of 23.6°C (74.5°F).Heat index
September's heat index is evaluated at a blistering 42°C (107.6°F). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.For clarity, heat index numbers account for light winds and areas under shade. If exposed to direct sunlight, the heat index could climb by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', binds temperature metrics with humidity values to give a sense of the actual warmth. Depending on the activity and the individual's heat perception, which may vary due to factors including wind, clothing, and metabolic variations, this effect remains subjective. Exposure to direct sun rays can influence the heat you feel, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it's vital to remain hydrated, particularly during prolonged physical activities.
Evaporating sweat is a key way the human body dispels excessive warmth, all thanks to the process of perspiration. Relative humidity in excess curtails evaporation, therefore reducing heat dissipation from the body, leading to feelings of excess heat. The body is at risk of dehydration and related complications when it fails to shed excessive heat.
Humidity
The months with the highest humidity are August and September, with an average relative humidity of 85%.Rainfall
In Boe, in September, during 22.2 rainfall days, 168mm (6.61") of precipitation is typically accumulated. In Boe, during the entire year, the rain falls for 109.7 days and collects up to 868mm (34.17") of precipitation.Daylight
The average length of the day in September is 12h and 11min.On the first day of the month, sunrise is at 06:46 and sunset at 19:06. On the last day of September, sunrise is at 06:45 and sunset at 18:47 GMT.
Sunshine
In September, the average sunshine is 6.4h.UV index
The months with the highest UV index are January through July, September through December, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index, 7 in September, converts into the following recommendations:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. The Sun's UV radiation is most intense from 10 a.m. to 4 p.m. Try to avoid direct sun exposure during these hours. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Boe, Guinea-Bissau
- Average high temperature in September: 30.9°C
The warmest month (with the highest average high temperature) is March (40.2°C).
The month with the lowest average high temperature is August (29.9°C).
- Average low temperature in September: 23.6°C
The month with the highest average low temperature is June (25.1°C).
The coldest month (with the lowest average low temperature) is February (18.5°C).
Average pressure in September
Boe, Guinea-Bissau
- Average pressure in September: 1012.4mbar
The month with the highest atmospheric pressure is July (1013mbar).
The month with the lowest atmospheric pressure is April (1010mbar).
Average wind speed in September
Boe, Guinea-Bissau
- Average wind speed in September: 6.4km/h
The windiest month (with the highest average wind speed) is May (9.4km/h).
The calmest month (with the lowest average wind speed) is October (5.7km/h).
Average humidity in September
Boe, Guinea-Bissau
- Average humidity in September: 85%
The months with the highest relative humidity are August and September (85%).
The month with the lowest relative humidity is January (32%).
Average rainfall in September
Boe, Guinea-Bissau
- Average rainfall in September: 168mm
The wettest month (with the highest rainfall) is August (286mm).
The driest months (with the least rainfall) are January, February and December (0mm).
Average rainfall days in September
Boe, Guinea-Bissau
- Average rainfall days in September: 22.2 days
The month with the highest number of rainy days is August (25.7 days).
The months with the least rainy days are January and February (0 days).
Average daylight in September /
Average sunshine in September
Boe, Guinea-Bissau
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 12h and 48min).
The month with the shortest days is December (Average daylight: 11h and 30min).
- Average sunshine in September: 6h and 24min
The month with the most sunshine is March (Average sunshine: 10h and 0min).
The month with the least sunshine is August (Average sunshine: 5h and 6min).
Average sunshine days in September
Boe, Guinea-Bissau
- Average sunshine days in September: 6.5 days
The month with the most sunshine days is January (30.9 days).
The month with the least sunshine days is August (4 days).
Average UV index in September
Boe, Guinea-Bissau
- Average UV index in September: 7
The months with the highest UV index are January, February, March, April, May, June, July, September, October, November and December (UV index 7).
The month with the lowest UV index is August (UV index 6).
Average cloud cover in September
Boe, Guinea-Bissau
- Average cloud cover in September: 55
The month with the most cloud cover is August (Cloud cover 65).
The month with the least cloud cover is March (Cloud cover 7).
Average visibility in September
Boe, Guinea-Bissau
- Average visibility in September: 8km
The months with the highest visibility are January, February, March, April, May, June, November and December (10km).
The months with the lowest visibility are August and September (8km).





