September weather - Spring 2024

Weather in September
Frequently asked questions
Average temperature in September
Average pressure in September
Average wind speed in September
Average humidity in September
Average rainfall in September
Average rainfall days in September
Average daylight in September
Average sunshine in September
Average sunshine days in September
Average UV index in September
Average cloud cover in September
Average visibility in September

A small lake in Uhuru Park within the city of Nairobi, Kenya

Weather in September

With a steady rise in temperature, September signals the onset of the warm season in Nairobi. Following the consistent temperatures of August, September ends the cool weather streak and opens the door for warmer stormy months towards the year-end. The shift in weather does not contribute to an overly warm environment, with temperatures remaining comfortable around mid-twenties. Although rains are scarce towards the month's end, the city's overall ambiance stays fresh and inviting due to the balance between warmth and precipitation.

Temperature

September's climate in Nairobi shows a minor adjustment in average high-temperatures to a still moderately hot 24.6°C (76.3°F) from August's 23°C (73.4°F). September nights experience a consistent temperature drop to a refreshing 14.2°C (57.6°F).

Humidity

The average relative humidity in September is 67%.

Rainfall

In Nairobi, in September, it is raining for 16.5 days, with typically 31mm (1.22") of accumulated precipitation. Throughout the year, there are 241.5 rainfall days, and 676mm (26.61") of precipitation is accumulated.

Daylight

The average length of the day in September in Nairobi is 12h and 7min.
On the first day of September, sunrise is at 06:29 and sunset at 18:35. On the last day of the month, sunrise is at 06:18 and sunset at 18:26 EAT.

Sunshine

The average sunshine in September is 9.4h.

UV index

September is the month with the highest UV index in Nairobi, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for the ordinary person.
Note: The UV index of 6 during September leads to these advisories:
Guard oneself from overexposure. Defence against sun injury is vital. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. Employ a wide-brim hat for potent defense against up to 50% of UV rays.

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Frequently asked questions

What is the usual temperature for Nairobi in September?

During September, Nairobi experiences an average high-temperature of 24.6°C (76.3°F) and a low-temperature of 14.2°C (57.6°F). In February, the average heat index (a.k.a. 'real feel', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, is estimated at 28°C (82.4°F).

What is the average humidity in September in Nairobi?

In Nairobi, the average relative humidity in September is 67%.

How many days does it rain in September in Nairobi?

In Nairobi, Kenya, in September, during 16.5 rainfall days, 31mm (1.22") of precipitation is typically accumulated.

What is the average length of the day in September in Nairobi?

In September, the average day length in Nairobi is 12h and 7min.

When are sunrise and sunset in September in Nairobi?

On the first day of September in Nairobi, sunrise is at 06:29 and sunset at 18:35. On the last day of the month, sunrise is at 06:18 and sunset at 18:26 EAT.

How long on average sun shines in September in Nairobi?

In Nairobi, the average sunshine duration in September is 9.4h.

What is the month with the highest UV index in Nairobi?

September is the month with the highest UV index, with an average maximum UV index of 6.

What is the UV index reading in September in Nairobi?

The average daily maximum UV index in September in Nairobi is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unsafe exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

23°C 73.4°F

24.6°C 76.3°F

25.3°C 77.5°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

9.2km/h 5.7mph

9.8km/h 6.1mph

11.9km/h 7.4mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average daylight

Average sunshine

Average sunshine days

11.4

10.3

6.5

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Nairobi, Kenya

Average high temperature in September: 24.6°C

The warmest month (with the highest average high temperature) is February (27°C).
The month with the lowest average high temperature is June (22.4°C).

Average low temperature in September: 14.2°C

The month with the highest average low temperature is April (15.6°C).
The coldest month (with the lowest average low temperature) is July (12.7°C).

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Average pressure in September
Nairobi, Kenya

Average pressure in September: 1015.6mbar

The month with the highest atmospheric pressure is July (1016.8mbar).
The months with the lowest atmospheric pressure are February and March (1013.4mbar).

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Average wind speed in September
Nairobi, Kenya

Average wind speed in September: 9.1km/h

The windiest month (with the highest average wind speed) is February (11.8km/h).
The calmest month (with the lowest average wind speed) is June (6.1km/h).

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Average humidity in September
Nairobi, Kenya

Average humidity in September: 67%

The month with the highest relative humidity is May (84%).
The month with the lowest relative humidity is February (65%).

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Average rainfall in September
Nairobi, Kenya

Average rainfall in September: 31mm

The wettest month (with the highest rainfall) is April (125mm).
The driest month (with the least rainfall) is January (28mm).

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Average rainfall days in September
Nairobi, Kenya

Average rainfall days in September: 16.5 days

The month with the highest number of rainy days is May (27.7 days).
The month with the least rainy days is January (12.3 days).

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Average daylight in September /
Average sunshine in September
Nairobi, Kenya

Average daylight in September: 12h and 1min

The month with the longest days is December (Average daylight: 12h and 12min).
The month with the shortest days is June (Average daylight: 12h and 0min).

Average sunshine in September: 9h and 2min

The months with the most sunshine are January and February (Average sunshine: 9h and 36min).
The months with the least sunshine are April and May (Average sunshine: 8h and 30min).

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Average sunshine days in September
Nairobi, Kenya

Average sunshine days in September: 10.3 days

The month with the most sunshine days is January (15.3 days).
The month with the least sunshine days is April (1.9 days).

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Average UV index in September
Nairobi, Kenya

Average UV index in September: 6

The month with the highest UV index is September (UV index 6).
The months with the lowest UV index are January, February, March, April, May, June, July, August, October, November and December (UV index 5).

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Average cloud cover in September
Nairobi, Kenya

Average cloud cover in September: 36

The month with the most cloud cover is May (Cloud cover 54).
The month with the least cloud cover is February (Cloud cover 25).

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Average visibility in September
Nairobi, Kenya

Average visibility in September: 10km

The months with the highest visibility are September and October (10km).
The months with the lowest visibility are April and May (7km).

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September weather forecast
Nairobi, Kenya

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