September registers a decline in the wet season, although the average rainfall still remains high at 92mm (3.62"). Also, the sea's temperature is at its warmest, reaching 28.2°C (82.8°F), inviting those seeking to do water activities. The average high temperature drops slightly to 32.3°C (90.1°F), and nocturnal temperatures stay at 25.1°C (77.2°F), making nights very warm. Simultaneously, the relative humidity registers at 78.5%, and daylight lasts for about 12.2 hours. Variety remains the spice of life this month in
Saint Louis, as the weather promises equal measures of rain and sunshine, giving tourists a unique mix of experiences to enjoy in this Senegalese city.
Temperature
The commencement of September brings an average high-temperature of a still hot 32.3°C (90.1°F), marking an inconsequential divergence from
August. Saint Louis in September experiences a low-temperature average of 25.1°C (77.2°F).
Heat index
For September, the heat index is computed to be a life-threatening hot 45°C (113°F).
Attention: Heat exhaustion and heat cramps are anticipated. Prolonged effort can result in heatstroke.
Heat index specifics point out values are for conditions of shade and a slight breeze. An exposure to direct sunlight may lift the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', unifies temperature and humidity readings to offer a comprehensive feel of warmth. A person's impression of weather can be swayed by numerous aspects, among them metabolic variations, pregnancy, and activity levels. 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 highly critical 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.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. An increase in relative humidity retards evaporation, subsequently reducing the body's heat removal rate and leading to a sensation of being overly warm. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.
Humidity
In Saint Louis, the average relative humidity in September is 78.5%.
Rainfall
In Saint Louis, in September, it is raining for 6 days, with typically 92mm (3.62") of accumulated precipitation. Throughout the year, there are 20 rainfall days, and 261mm (10.28") of precipitation is accumulated.
Sea temperature
With an average sea temperature of 28.2°C (82.8°F), September is the month with the warmest seawater.
Note: Water temperature ranging between 25°C (77°F) and 29°C (84.2°F) is considered very warm and pleasing for everyone. It allows for enjoyable water activities over extended periods without discomfort.
Daylight
In Saint Louis, the average length of the day in September is 12h and 13min.
On the first day of September, sunrise is at 06:52 and sunset at 19:18. On the last day of the month, sunrise is at 06:55 and sunset at 18:55 GMT.
Sunshine
The average sunshine in September is 7.6h.
UV index
March through September, with an average maximum UV index of 12, are months with the highest UV index in Saint Louis. A UV Index reading of 11, and higher, represents an excessive health risk from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index, 12 in September, converts into the following recommendations:
Put into action all important safeguards, unprotected skin may burn swiftly. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Broad-spectrum sunscreen with an SPF of 30 or above should be applied generously and reapplied every two hours and right after any outdoor activity or swim. Take note! The UV strength of the Sun elevates when reflected off water and sand.