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
During September, Porthmadog records an average high-temperature of a mild 14.8°C (58.6°F), marking a slight divergence from August's 16.5°C (61.7°F). Porthmadog throughout September, experiences an average nighttime temperature of 8.7°C (47.7°F).Humidity
In September, the average relative humidity in Porthmadog is 89%.Rainfall
In Porthmadog, during September, the rain falls for 18.3 days and regularly aggregates up to 61mm (2.4") of precipitation. In Porthmadog, United Kingdom, during the entire year, the rain falls for 230 days and collects up to 940mm (37.01") of precipitation.Snowfall
In Porthmadog, snow does not fall in May through October.Sea temperature
With an average sea temperature of 15.7°C (60.3°F), September is the month with the warmest seawater.Note: Most people do not find swimming enjoyable in water of 15.7°C (60.3°F). The task of controlling breathing becomes tougher as the temperature drops from 21°C (69.8°F) to 15°C (59°F).
Daylight
In Porthmadog, United Kingdom, the average length of the day in September is 12h and 40min.On the first day of the month, sunrise is at 6:27 am and sunset at 8:04 pm. On the last day of September, sunrise is at 7:17 am and sunset at 6:55 pm BST.
Sunshine
The average sunshine in September in Porthmadog is 4.9h.UV index
The average daily maximum UV index in September in Porthmadog is 3. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: An average UV index of 3 in September transforms into this advice:
Ensure safety - Imperative it is to shield skin and eyes from damage. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Frequently asked questions
What are the temperatures in Porthmadog in September?
What is the average humidity in September in Porthmadog?
How much does it rain in Porthmadog in September?
When it does not snow in Porthmadog?
What is the month with the warmest sea water in Porthmadog?
What is the sea water temperature in September in Porthmadog?
How many hours of daylight does Porthmadog have in September?
What time are sunrise and sunset in September in Porthmadog?
How many hours of sunshine does Porthmadog have in September?
How high is the UV index in September in Porthmadog?
Average temperature in September
Porthmadog, United Kingdom
- Average high temperature in September: 14.8°C
The warmest month (with the highest average high temperature) is July (17.2°C).
The month with the lowest average high temperature is January (5.6°C).
- Average low temperature in September: 8.7°C
The month with the highest average low temperature is August (10.6°C).
The coldest month (with the lowest average low temperature) is February (1.5°C).
Average pressure in September
Porthmadog, United Kingdom
- Average pressure in September: 1015.9mbar
The month with the highest atmospheric pressure is May (1016.3mbar).
The month with the lowest atmospheric pressure is November (1009.1mbar).
Average wind speed in September
Porthmadog, United Kingdom
- Average wind speed in September: 12.7km/h
The windiest month (with the highest average wind speed) is December (17.8km/h).
The calmest month (with the lowest average wind speed) is June (11.2km/h).
Average humidity in September
Porthmadog, United Kingdom
- Average humidity in September: 89%
The months with the highest relative humidity are January and December (91%).
The months with the lowest relative humidity are April and May (84%).
Average rainfall in September
Porthmadog, United Kingdom
- Average rainfall in September: 61mm
The wettest month (with the highest rainfall) is December (103mm).
The driest months (with the least rainfall) are April and May (52mm).
Average rainfall days in September
Porthmadog, United Kingdom
- Average rainfall days in September: 18.3 days
The month with the highest number of rainy days is August (22.4 days).
The month with the least rainy days is February (15.3 days).
Average snowfall in September
Porthmadog, United Kingdom
- Average snowfall in September: 0mm
The month with the highest snowfall is January (70mm).
The months with the least snowfall are May, June, July, August, September and October (0mm).
Average snowfall days in September
Porthmadog, United Kingdom
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (6.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in September
Porthmadog, United Kingdom
- Average sea temperature in September: 15.7°C
The best month for swimming (with the highest average sea temperature) is September (15.7°C).
The coldest months (with the lowest average sea temperature) are February and March (8.3°C).
Average daylight in September /
Average sunshine in September
Porthmadog, United Kingdom
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 48min).
The month with the shortest days is December (Average daylight: 7h and 42min).
- Average sunshine in September: 4h and 5min
The months with the most sunshine are May and June (Average sunshine: 6h and 12min).
The month with the least sunshine is December (Average sunshine: 2h and 30min).
Average sunshine days in September
Porthmadog, United Kingdom
- Average sunshine days in September: 8.5 days
The month with the most sunshine days is March (10.8 days).
The month with the least sunshine days is August (5.9 days).
Average UV index in September
Porthmadog, United Kingdom
- Average UV index in September: 3
The months with the highest UV index are May, June and August (UV index 4).
The months with the lowest UV index are January, February, March, April, November and December (UV index 2).
Average cloud cover in September
Porthmadog, United Kingdom
- Average cloud cover in September: 68
The month with the most cloud cover is December (Cloud cover 76).
The month with the least cloud cover is April (Cloud cover 60).
Average visibility in September
Porthmadog, United Kingdom
- Average visibility in September: 7km
The months with the highest visibility are January, February, March, April, May, June, July, October, November and December (8km).
The months with the lowest visibility are August and September (7km).
Porthmadog, United Kingdom
Weather forecast for your location
2. Allow the app to use your location
