Climate - St. Louis (Senegal)

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The climate of Saint-Louis is tropical arid, with a long, dry season from November to May, and a rainy season from June to October.
The city (also known as Ndar) is located in the northwest of Senegal, on the coast, and at the mouth of the Senegal River, beyond which lies Mauritania.
The old city is located on an island, in front of which there is a barrier island, called Langue de Barbarie.
To the northeast is the Djoudj National Bird Sanctuary. To the south-west is the Lompoul desert.
The length of the rainy period and the amount of rainfall varies according to the years, however, the region of Saint-Louis, where precipitation drops below 400 mm (15.5 in) per year, is the driest in the country.
During the day it is hot all year round, but from December to February the nights are quite cool and the humidity is quite low.

St. Louis - Climate data

The average temperature of the coldest month (January) is of 24.1 °C (75.4 °F), that of the warmest month (October) is of 29.5 °C (85.1 °F). Here are the average temperatures.
Precipitation amounts to 325 millimeters (12.8 inches) per year: it is therefore scarce. It ranges from 0 mm (0 in) in the driest months (March, April, May, November) to 120 mm (4.7 in) in the wettest one (September). Here is the average precipitation.
The sea temperature ranges from 19.5 °C (67 °F) in February, March to 28.5 °C (83 °F) in September. Here are the average sea temperatures.
On average, there are around 3005 sunshine hours per year. Here are the average sunshine hours per day.

St. Louis - Weather by month

Based on the period 1991-2020

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In January, the coldest month of the year, the weather in St. Louis is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 24.1 °C (75 °F), with a minimum of 16.8 °C (62.3 °F) and a maximum of 31.4 °C (88.6 °F).
On the coldest nights of the month, the temperature usually drops to around 13 °C (55 °F).
On the warmest days of the month, the temperature usually reaches around 37 °C (98.5 °F).
Precipitation amounts to only 5 mm (0.2 in), and all occurs in one day.
The day lasts on average 11 hours and 20 minutes.
There are on average 8 sunshine hours per day. So, the sun shines 69% of the time.
The average humidity is 45%.
The average wind speed is 13 kph (8 mph).
The average sea temperature is of 20.5 °C (69 °F). Therefore, the sea is cool for swimming.

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In February, the weather in St. Louis is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 25 °C (77 °F), with a minimum of 17.6 °C (63.8 °F) and a maximum of 32.4 °C (90.2 °F).
On the coldest nights of the month, the temperature usually drops to around 14 °C (57 °F).
On the warmest days of the month, the temperature usually reaches around 38.5 °C (101 °F).
Precipitation amounts to only 8 mm (0.3 in), and all occurs in one day.
The day lasts on average 11 hours and 35 minutes.
There are on average 8.5 sunshine hours per day. So, the sun shines 73% of the time.
The average humidity is 49%.
The average wind speed is 14 kph (9 mph).
The average sea temperature is of 19.5 °C (67 °F). Therefore, the sea is very cool for swimming.

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In March, the weather in St. Louis is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 25.6 °C (78 °F), with a minimum of 18.3 °C (65 °F) and a maximum of 33 °C (91.3 °F).
On the coldest nights of the month, the temperature usually drops to around 15 °C (59 °F).
On the warmest days of the month, the temperature usually reaches around 40.5 °C (105.5 °F).
Precipitation amounts to only 0 mm (0 in), so on average it never rains in the whole month.
The day lasts on average 12 hours and 5 minutes.
There are on average 9 sunshine hours per day. So, the sun shines 74% of the time.
The average humidity is 57%.
The average wind speed is 16 kph (10 mph).
The average sea temperature is of 19.5 °C (67 °F). Therefore, the sea is very cool for swimming.

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In April, the weather in St. Louis is usually warm to hot. The average temperature is of 25.1 °C (77 °F), with a minimum of 18.7 °C (65.7 °F) and a maximum of 31.5 °C (88.7 °F).
On the coldest nights of the month, the temperature usually drops to around 15.5 °C (60 °F).
On the warmest days of the month, the temperature usually reaches around 42 °C (107 °F).
Precipitation amounts to only 0 mm (0 in), so on average it never rains in the whole month.
The day lasts on average 12 hours and 30 minutes.
There are on average 9.5 sunshine hours per day. So, the sun shines 76% of the time.
The average humidity is 66%.
The average wind speed is 17 kph (11 mph).
The average sea temperature is of 20 °C (67.5 °F). Therefore, the sea is very cool for swimming.

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In May, the weather in St. Louis is usually warm to hot. The average temperature is of 25.2 °C (77 °F), with a minimum of 20 °C (68.1 °F) and a maximum of 30.3 °C (86.5 °F).
On the coldest nights of the month, the temperature usually drops to around 17 °C (62.5 °F).
On the warmest days of the month, the temperature usually reaches around 40 °C (104 °F).
Precipitation amounts to only 0 mm (0 in), so on average it never rains in the whole month.
The day lasts on average 12 hours and 55 minutes.
There are on average 9 sunshine hours per day. So, the sun shines 70% of the time.
The average humidity is 73%. Hence, the air is normally humid.
The average wind speed is 17 kph (10 mph).
The average sea temperature is of 21 °C (69.5 °F). Therefore, the sea is cool for swimming.

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In June, the weather in St. Louis is usually warm to hot. The average temperature is of 26.7 °C (80 °F), with a minimum of 22.9 °C (73.2 °F) and a maximum of 30.6 °C (87 °F).
On the coldest nights of the month, the temperature usually drops to around 20 °C (67.5 °F).
On the warmest days of the month, the temperature usually reaches around 39 °C (102.5 °F).
Precipitation amounts to only 7 mm (0.3 in), and all occurs in one day.
The day lasts on average 13 hours and 5 minutes. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 7.5 sunshine hours per day. So, the sun shines 57% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 14 kph (9 mph).
The average sea temperature is of 24 °C (75 °F). Therefore, the sea is warm enough for swimming.

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In July, the weather in St. Louis is usually very hot. The average temperature is of 28.1 °C (83 °F), with a minimum of 24.7 °C (76.5 °F) and a maximum of 31.5 °C (88.6 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F).
On the warmest days of the month, the temperature usually reaches around 37 °C (98.5 °F).
Precipitation amounts to 45 mm (1.8 in), distributed over 4 days.
The day lasts on average 13 hours and 0 minutes.
There are on average 8 sunshine hours per day. So, the sun shines 61% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 14 kph (9 mph).
The average sea temperature is of 26.5 °C (79.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

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In August, the weather in St. Louis is usually very hot. The average temperature is of 28.8 °C (84 °F), with a minimum of 25.3 °C (77.6 °F) and a maximum of 32.2 °C (90 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F).
On the warmest days of the month, the temperature usually reaches around 36.5 °C (98 °F).
Precipitation amounts to 105 mm (4.1 in), distributed over 8 days.
The day lasts on average 12 hours and 35 minutes.
There are on average 8 sunshine hours per day. So, the sun shines 64% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is 12 kph (8 mph).
The average sea temperature is of 28 °C (82 °F). Therefore, the sea is pleasantly warm and allows long swims.

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In September, the weather in St. Louis is usually very hot. The average temperature is of 29.2 °C (84 °F), with a minimum of 25.3 °C (77.6 °F) and a maximum of 33 °C (91.4 °F).
On the coldest nights of the month, the temperature usually drops to around 20.5 °C (69 °F).
On the warmest days of the month, the temperature usually reaches around 38.5 °C (101 °F).
Precipitation amounts to 120 mm (4.7 in), distributed over 8 days.
The day lasts on average 12 hours and 10 minutes.
There are on average 7.5 sunshine hours per day. So, the sun shines 62% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 28.5 °C (83 °F). Therefore, the sea is pleasantly warm and allows long swims.

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In October, the warmest month of the year, the weather in St. Louis is usually very hot. The average temperature is of 29.5 °C (85 °F), with a minimum of 24.4 °C (75.9 °F) and a maximum of 34.7 °C (94.4 °F).
On the coldest nights of the month, the temperature usually drops to around 20 °C (68.5 °F).
On the warmest days of the month, the temperature usually reaches around 41 °C (106 °F).
Precipitation amounts to 30 mm (1.2 in), distributed over 2 days.
The day lasts on average 11 hours and 50 minutes.
There are on average 8.5 sunshine hours per day. So, the sun shines 71% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).
The average sea temperature is of 28 °C (82 °F). Therefore, the sea is pleasantly warm and allows long swims.

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In November, the weather in St. Louis is usually very hot. However, there are remarkable differences between night and day. The average temperature is of 27.8 °C (82 °F), with a minimum of 20.9 °C (69.7 °F) and a maximum of 34.6 °C (94.4 °F).
On the coldest nights of the month, the temperature usually drops to around 17 °C (62.5 °F).
On the warmest days of the month, the temperature usually reaches around 40 °C (104 °F).
Precipitation amounts to only 0 mm (0 in), so on average it never rains in the whole month.
The day lasts on average 11 hours and 25 minutes.
There are on average 8 sunshine hours per day. So, the sun shines 72% of the time.
The average humidity is 56%.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 26 °C (78.5 °F). Therefore, the sea is warm enough for swimming.

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In December, the weather in St. Louis is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 25.2 °C (77 °F), with a minimum of 18.1 °C (64.5 °F) and a maximum of 32.3 °C (90.2 °F).
On the coldest nights of the month, the temperature usually drops to around 14 °C (57 °F).
On the warmest days of the month, the temperature usually reaches around 38 °C (100.5 °F).
Precipitation amounts to 10 mm (0.4 in), and all occurs in one day.
The day lasts on average 11 hours and 10 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 7.5 sunshine hours per day. So, the sun shines 67% of the time.
The average humidity is 49%.
The average wind speed is 12 kph (7 mph).
The average sea temperature is of 23 °C (74 °F). Therefore, the sea can be considered barely acceptable for swimming.