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
The shift into September finds Castleknock at an average high-temperature of a moderate 15.3°C (59.5°F), closely comparable to August's conditions. An average temperature of 9.1°C (48.4°F) marks the nights in September.Humidity
In September, the average relative humidity is 88%.Rainfall
In Castleknock, in September, during 17.8 rainfall days, 46mm (1.81") of precipitation is typically accumulated. In Castleknock, during the entire year, the rain falls for 209.2 days and collects up to 564mm (22.2") of precipitation.Snowfall
In Castleknock, snow does not fall in April through October.Daylight
In September, the average length of the day in Castleknock is 12h and 41min.On the first day of September in Castleknock, sunrise is at 6:35 am and sunset at 8:14 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 7:04 pm IST.
Sunshine
The average sunshine in September in Castleknock, Ireland, is 6.1h.UV index
In September, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: In September, the average maximum UV index of 3 translates into the following recommendations:
Heed the precautions - It is counselled to guard against solar damage. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Frequently asked questions
What is the temperature in September in Castleknock?
What is the average humidity in September in Castleknock?
How much does it rain in Castleknock in September?
When it does not snow in Castleknock?
What is the average length of the day in September in Castleknock?
What time are sunrise and sunset in September in Castleknock?
How many hours of sunshine does Castleknock have in September?
How high is the UV index in September in Castleknock?
Average temperature in September
Castleknock, Ireland
- Average high temperature in September: 15.3°C
The warmest month (with the highest average high temperature) is July (17.3°C).
The month with the lowest average high temperature is January (7°C).
- Average low temperature in September: 9.1°C
The month with the highest average low temperature is July (11.2°C).
The coldest month (with the lowest average low temperature) is February (2.5°C).
Average pressure in September
Castleknock, Ireland
- Average pressure in September: 1015.3mbar
The month with the highest atmospheric pressure is May (1016mbar).
The month with the lowest atmospheric pressure is November (1008.3mbar).
Average wind speed in September
Castleknock, Ireland
- Average wind speed in September: 15.3km/h
The windiest month (with the highest average wind speed) is January (21.1km/h).
The calmest months (with the lowest average wind speed) are June and July (13.6km/h).
Average humidity in September
Castleknock, Ireland
- Average humidity in September: 88%
The month with the highest relative humidity is December (90%).
The months with the lowest relative humidity are March, April and May (85%).
Average rainfall in September
Castleknock, Ireland
- Average rainfall in September: 46mm
The wettest month (with the highest rainfall) is August (71mm).
The driest month (with the least rainfall) is April (30mm).
Average rainfall days in September
Castleknock, Ireland
- Average rainfall days in September: 17.8 days
The month with the highest number of rainy days is August (24.2 days).
The month with the least rainy days is February (13.6 days).
Average snowfall in September
Castleknock, Ireland
- Average snowfall in September: 0mm
The month with the highest snowfall is February (19mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).
Average snowfall days in September
Castleknock, Ireland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.4 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Castleknock, Ireland
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 54min).
The month with the shortest days is December (Average daylight: 7h and 36min).
- Average sunshine in September: 6h and 1min
The months with the most sunshine are April and May (Average sunshine: 6h and 42min).
The months with the least sunshine are February, October and November (Average sunshine: 3h and 54min).
Average sunshine days in September
Castleknock, Ireland
- Average sunshine days in September: 9 days
The month with the most sunshine days is January (13.2 days).
The month with the least sunshine days is August (3.4 days).
Average UV index in September
Castleknock, Ireland
- 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, November and December (UV index 2).
Average cloud cover in September
Castleknock, Ireland
- Average cloud cover in September: 58
The month with the most cloud cover is July (Cloud cover 64).
The month with the least cloud cover is April (Cloud cover 55).
Average visibility in September
Castleknock, Ireland
- Average visibility in September: 8km
The months with the highest visibility are January, February, March, April, May, June, October, November and December (9km).
The months with the lowest visibility are July, August and September (8km).
Castleknock, Ireland
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