September weather forecastScilly, Ireland
September
Weather in September
The first month of the autumn, September, is still a refreshing month in Scilly, Ireland, with an average temperature varying between 10.5°C (50.9°F) and 15.9°C (60.6°F).Temperature
The initiation of September sees an average high-temperature of a mild 15.9°C (60.6°F), showing minor variations from the previous month. During the month of September, Scilly's nighttime temperature lowers to an average of 10.5°C (50.9°F).Humidity
The average relative humidity in September is 86%.Rainfall
In Scilly, in September, during 15.3 rainfall days, 41mm (1.61") of precipitation is typically accumulated. In Scilly, Ireland, during the entire year, the rain falls for 198 days and collects up to 586mm (23.07") of precipitation.Snowfall
In Scilly, snow does not fall in April through October.Daylight
In September, the average length of the day in Scilly is 12h and 38min.On the first day of September, sunrise is at 6:47 am and sunset at 8:20 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 7:13 pm IST.
Sunshine
In September, the average sunshine is 6.3h.UV index
The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: In September, a daily maximum UV index of 3 leads to the following instructions:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Scilly, Ireland
- Average high temperature in September: 15.9°C
The warmest month (with the highest average high temperature) is July (17.8°C).
The month with the lowest average high temperature is January (8.3°C).
- Average low temperature in September: 10.5°C
The month with the highest average low temperature is July (12.1°C).
The coldest month (with the lowest average low temperature) is February (3.9°C).
Average pressure in September
Scilly, Ireland
- Average pressure in September: 1016.2mbar
The month with the highest atmospheric pressure is May (1016.4mbar).
The month with the lowest atmospheric pressure is November (1009mbar).
Average wind speed in September
Scilly, Ireland
- Average wind speed in September: 17.5km/h
The windiest month (with the highest average wind speed) is December (23.5km/h).
The calmest months (with the lowest average wind speed) are June and July (16.1km/h).
Average humidity in September
Scilly, Ireland
- Average humidity in September: 86%
The months with the highest relative humidity are October and December (87%).
The months with the lowest relative humidity are February, March and April (84%).
Average rainfall in September
Scilly, Ireland
- Average rainfall in September: 41mm
The wettest month (with the highest rainfall) is December (66mm).
The driest month (with the least rainfall) is March (33mm).
Average rainfall days in September
Scilly, Ireland
- Average rainfall days in September: 15.3 days
The month with the highest number of rainy days is July (21.3 days).
The month with the least rainy days is February (13.5 days).
Average snowfall in September
Scilly, Ireland
- Average snowfall in September: 0mm
The month with the highest snowfall is March (6mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).
Average snowfall days in September
Scilly, Ireland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Scilly, Ireland
- Average daylight in September: 12h and 36min
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: 6h and 18min
The month with the most sunshine is June (Average sunshine: 7h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Scilly, Ireland
- Average sunshine days in September: 10.5 days
The month with the most sunshine days is March (14.3 days).
The month with the least sunshine days is August (5.8 days).
Average UV index in September
Scilly, Ireland
- Average UV index in September: 3
The months with the highest UV index are June, July and August (UV index 4).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Scilly, Ireland
- Average cloud cover in September: 53
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is April (Cloud cover 52).
Average visibility in September
Scilly, Ireland
- Average visibility in September: 9km
The months with the highest visibility are February and March (10km).
The months with the lowest visibility are January, April, May, June, July, August, September, October, November and December (9km).





