September weather forecastDonegal, Ireland
September
Weather in September
September in Donegal, Ireland, signifies the transition from summer to autumn. The landscape begins to adopt varying hues, rendering it breathtakingly beautiful. Autumn signals its arrival with falling leaves, and a noticeable change in weather conditions. The rainfall in September decreases to an average of 49mm (1.93") from 87mm (3.43") in August. September offers an assorted mix of weather conditions, alternately sunny and damp, making the surroundings more lively and colorful.Temperature
Donegal experiences a minor change to a still moderate 14.5°C (58.1°F) in average high-temperature during September, closely reflecting August. Donegal maintains an average of approximately a frosty 9.5°C (49.1°F) during September nights, with only a minimal decrease from the daytime temperature.Humidity
In Donegal, the average relative humidity in September is 87%.Rainfall
In Donegal, during September, the rain falls for 20.5 days and regularly aggregates up to 49mm (1.93") of precipitation. In Donegal, during the entire year, the rain falls for 249.6 days and collects up to 779mm (30.67") of precipitation.Snowfall
April through October are months without snowfall in Donegal.Sea temperature
In Donegal, the average seawater temperature in September is 14.3°C (57.7°F).Note: With the appropriate swimsuit, one can swim in 14.3°C (57.7°F) even if temperatures dip below 10°C (50°F); otherwise, be ready for cold shock and breath issues. A fleeting swim around 13°C (55.4°F) is distressing.
Daylight
The average length of the day in September in Donegal is 12h and 43min.On the first day of September, sunrise is at 6:40 am and sunset at 8:23 pm. On the last day of the month, sunrise is at 7:33 am and sunset at 7:10 pm IST.
Sunshine
In Donegal, the average sunshine in September is 4.8h.UV index
In September, the average daily maximum UV index in Donegal is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The daily high UV index of 3 during September translates into the following recommendations:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Donegal, Ireland
- Average high temperature in September: 14.5°C
The warmest month (with the highest average high temperature) is July (16.3°C).
The month with the lowest average high temperature is January (6.4°C).
- Average low temperature in September: 9.5°C
The month with the highest average low temperature is August (10.8°C).
The coldest month (with the lowest average low temperature) is January (2.9°C).
Average pressure in September
Donegal, Ireland
- Average pressure in September: 1013.8mbar
The month with the highest atmospheric pressure is May (1015.2mbar).
The month with the lowest atmospheric pressure is November (1006.7mbar).
Average wind speed in September
Donegal, Ireland
- Average wind speed in September: 16.5km/h
The windiest month (with the highest average wind speed) is January (22.1km/h).
The calmest month (with the lowest average wind speed) is July (13.6km/h).
Average humidity in September
Donegal, Ireland
- Average humidity in September: 87%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is April (82%).
Average rainfall in September
Donegal, Ireland
- Average rainfall in September: 49mm
The wettest month (with the highest rainfall) is August (87mm).
The driest month (with the least rainfall) is April (34mm).
Average rainfall days in September
Donegal, Ireland
- Average rainfall days in September: 20.5 days
The month with the highest number of rainy days is August (25.2 days).
The month with the least rainy days is April (17.8 days).
Average snowfall in September
Donegal, Ireland
- Average snowfall in September: 0mm
The month with the highest snowfall is January (41mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).
Average snowfall days in September
Donegal, Ireland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Donegal, Ireland
- Average sea temperature in September: 14.3°C
The best month for swimming (with the highest average sea temperature) is August (14.8°C).
The coldest month (with the lowest average sea temperature) is March (9.2°C).
Average daylight in September /
Average sunshine in September
Donegal, Ireland
- Average daylight in September: 12h and 42min
The month with the longest days is June (Average daylight: 17h and 12min).
The month with the shortest days is December (Average daylight: 7h and 24min).
- Average sunshine in September: 4h and 48min
The month with the most sunshine is June (Average sunshine: 6h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 6min).
Average sunshine days in September
Donegal, Ireland
- Average sunshine days in September: 6.6 days
The month with the most sunshine days is April (9.5 days).
The month with the least sunshine days is August (3.4 days).
Average UV index in September
Donegal, Ireland
- Average UV index in September: 3
The months with the highest UV index are May and June (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
Donegal, Ireland
- Average cloud cover in September: 66
The months with the most cloud cover are January and August (Cloud cover 70).
The month with the least cloud cover is April (Cloud cover 59).
Average visibility in September
Donegal, Ireland
- Average visibility in September: 9km
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (9km).
The month with the lowest visibility is July (8km).
