average weather in ireland in october
4. Re: Weather in early October. Aug 21, 2010, 11:36 AM. Average day time temperatures in October are 14 degrees celsius in the day time and 9 degrees celsius at night. It could be colder and it's certainly likely to be wet. Weather in Ireland is changeable at any time of the year so layers are the best way to go - t-shirts, shirts, fleeces, waterproof jacket and shoes.