Contents
- 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 snowfall in September
- Average snowfall days in September
- Average sea temperature 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
Weather in September
Temperature
The arrival of September brings an average high-temperature of a still enjoyable 17.1°C (62.8°F), nearly identical to August's 18.5°C (65.3°F). In Cardiff, an average nighttime temperature of 11.4°C (52.5°F) is expected during September.Humidity
The average relative humidity in September in Cardiff is 83%.Rainfall
In Cardiff, during September, the rain falls for 10 days and regularly aggregates up to 17mm (0.67") of precipitation. In Cardiff, during the entire year, the rain falls for 132.6 days and collects up to 252mm (9.92") of precipitation.Snowfall
March through October are months without snowfall in Cardiff.Sea temperature
The months with the warmest seawater in Cardiff, United Kingdom, are August and September, with an average sea temperature of 16.6°C (61.9°F).Note: Swimming in water with a temperature of 16.6°C (61.9°F) is not a pleasurable experience for the majority. As the temperature falls below 21°C (69.8°F), it becomes increasingly hard to control one's breathing.
Daylight
In September, the average length of the day in Cardiff is 12h and 38min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:58 pm. On the last day of September, sunrise is at 7:12 am and sunset at 6:52 pm BST.
Sunshine
In September, the average sunshine in Cardiff is 7.2h.UV index
May through September, with an average maximum UV index of 4, are months with the highest UV index. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 4 during September leads to these advisories:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Frequently asked questions
What is the usual temperature for Cardiff in September?
What is the average humidity in September in Cardiff?
How many days does it rain in September in Cardiff?
When it does not snow in Cardiff?
What months are the sea warmest in Cardiff?
What is the sea temperature in September in Cardiff?
How many hours of daylight does Cardiff have in September?
When is the sunrise / sunset in September in Cardiff?
How many hours of sunshine does Cardiff have in September?
What are the months with the highest UV index in Cardiff?
How high is the UV index in September in Cardiff?
Average temperature in September
Cardiff, United Kingdom
- Average high temperature in September: 17.1°C
The warmest month (with the highest average high temperature) is July (19°C).
The month with the lowest average high temperature is January (7.5°C).
- Average low temperature in September: 11.4°C
The month with the highest average low temperature is August (13.3°C).
The coldest month (with the lowest average low temperature) is February (3.9°C).
Average pressure in September
Cardiff, United Kingdom
- Average pressure in September: 1016.8mbar
The month with the highest atmospheric pressure is September (1016.8mbar).
The month with the lowest atmospheric pressure is November (1010mbar).
Average wind speed in September
Cardiff, United Kingdom
- Average wind speed in September: 16.3km/h
The windiest month (with the highest average wind speed) is February (22.3km/h).
The calmest months (with the lowest average wind speed) are June and July (15.2km/h).
Average humidity in September
Cardiff, United Kingdom
- Average humidity in September: 83%
The months with the highest relative humidity are November and December (86%).
The months with the lowest relative humidity are April and May (81%).
Average rainfall in September
Cardiff, United Kingdom
- Average rainfall in September: 17mm
The wettest months (with the highest rainfall) are August and November (31mm).
The driest month (with the least rainfall) is April (12mm).
Average rainfall days in September
Cardiff, United Kingdom
- Average rainfall days in September: 10 days
The month with the highest number of rainy days is November (13.5 days).
The months with the least rainy days are February and April (9.1 days).
Average snowfall in September
Cardiff, United Kingdom
- Average snowfall in September: 0mm
The month with the highest snowfall is February (5mm).
The months with the least snowfall are March, April, May, June, July, August, September and October (0mm).
Average snowfall days in September
Cardiff, United Kingdom
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature in September
Cardiff, United Kingdom
- Average sea temperature in September: 16.6°C
The best months for swimming (with the highest average sea temperature) are August and September (16.6°C).
The coldest month (with the lowest average sea temperature) is March (8.7°C).
Average daylight in September /
Average sunshine in September
Cardiff, United Kingdom
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 36min).
The month with the shortest days is December (Average daylight: 7h and 54min).
- Average sunshine in September: 7h and 1min
The month with the most sunshine is May (Average sunshine: 8h and 12min).
The month with the least sunshine is November (Average sunshine: 3h and 54min).
Average sunshine days in September
Cardiff, United Kingdom
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is April (19.2 days).
The month with the least sunshine days is November (13.7 days).
Average UV index in September
Cardiff, United Kingdom
- Average UV index in September: 4
The months with the highest UV index are May, June, July, August and September (UV index 4).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Cardiff, United Kingdom
- Average cloud cover in September: 50
The month with the most cloud cover is November (Cloud cover 61).
The months with the least cloud cover are April and May (Cloud cover 46).
Average visibility in September
Cardiff, United Kingdom
- Average visibility in September: 9km
The months with the highest visibility are February, March and December (10km).
The months with the lowest visibility are January, April, May, June, July, August, September, October and November (9km).
Cardiff, United Kingdom
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