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 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
Lettermakenny's average high-temperature marks a still refreshing 14.5°C (58.1°F) with the advent of September, closely mirroring that of the preceding month. The nighttime temperature, during September, averages of 8.4°C (47.1°F).Humidity
In September, the average relative humidity in Lettermakenny is 89%.Rainfall
In Lettermakenny, in September, during 20.3 rainfall days, 42mm (1.65") of precipitation is typically accumulated. Throughout the year, there are 240.4 rainfall days, and 703mm (27.68") of precipitation is accumulated.Snowfall
May through October are months without snowfall.Daylight
In Lettermakenny, the average length of the day in September is 12h and 43min.On the first day of September, sunrise is at 6:38 am and sunset at 8:23 pm. On the last day of the month, sunrise is at 7:32 am and sunset at 7:08 pm IST.
Sunshine
In Lettermakenny, the average sunshine in September is 4.6h.UV index
In Lettermakenny, Ireland, the average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: An average UV index of 3 in September transforms into this advice:
Be vigilant - Suggestions to stave off sun damage are provided. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Frequently asked questions
What is the usual temperature for Lettermakenny in September?
What is the average humidity in September in Lettermakenny?
How many days does it rain in September in Lettermakenny?
When it does not snow in Lettermakenny?
How many hours of daylight does Lettermakenny have in September?
When are sunrise and sunset in September in Lettermakenny?
How many hours of sunshine does Lettermakenny have in September?
What is the UV index intensity in September in Lettermakenny?
Average temperature in September
Lettermakenny, Ireland
- Average high temperature in September: 14.5°C
The warmest month (with the highest average high temperature) is July (16.6°C).
The month with the lowest average high temperature is January (5.9°C).
- Average low temperature in September: 8.4°C
The month with the highest average low temperature is July (9.9°C).
The coldest month (with the lowest average low temperature) is February (1.6°C).
Average pressure in September
Lettermakenny, Ireland
- Average pressure in September: 1013.8mbar
The month with the highest atmospheric pressure is May (1015.3mbar).
The month with the lowest atmospheric pressure is November (1006.8mbar).
Average wind speed in September
Lettermakenny, Ireland
- Average wind speed in September: 13.1km/h
The windiest month (with the highest average wind speed) is January (17.8km/h).
The calmest month (with the lowest average wind speed) is July (11.5km/h).
Average humidity in September
Lettermakenny, Ireland
- Average humidity in September: 89%
The month with the highest relative humidity is December (91%).
The month with the lowest relative humidity is April (84%).
Average rainfall in September
Lettermakenny, Ireland
- Average rainfall in September: 42mm
The wettest month (with the highest rainfall) is August (81mm).
The driest month (with the least rainfall) is April (39mm).
Average rainfall days in September
Lettermakenny, Ireland
- Average rainfall days in September: 20.3 days
The month with the highest number of rainy days is August (25.6 days).
The month with the least rainy days is February (15.8 days).
Average snowfall in September
Lettermakenny, Ireland
- Average snowfall in September: 0mm
The month with the highest snowfall is February (51mm).
The months with the least snowfall are May, June, July, August, September and October (0mm).
Average snowfall days in September
Lettermakenny, Ireland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.5 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Lettermakenny, Ireland
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 17h and 18min).
The month with the shortest days is December (Average daylight: 7h and 18min).
- Average sunshine in September: 4h and 4min
The month with the most sunshine is June (Average sunshine: 6h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 6min).
Average sunshine days in September
Lettermakenny, Ireland
- Average sunshine days in September: 5.6 days
The month with the most sunshine days is November (9.8 days).
The month with the least sunshine days is August (3.3 days).
Average UV index in September
Lettermakenny, Ireland
- Average UV index in September: 3
The month with the highest UV index is 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
Lettermakenny, Ireland
- Average cloud cover in September: 69
The month with the most cloud cover is August (Cloud cover 74).
The month with the least cloud cover is April (Cloud cover 61).
Average visibility in September
Lettermakenny, Ireland
- Average visibility in September: 7km
The month with the highest visibility is March (9km).
The months with the lowest visibility are July, August and September (7km).
Lettermakenny, Ireland
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