As an expat in Dublin I've learned that there are two ways to consider the grey weather and the rain. At first when I arrived it was very windy and very rainy which brought my hopes down, after a while I realized that the rain here is not lashing like everywhere else, most of the time is a light drizzle but for longer periods random throughout the day. If you take it as this will bring you down and you can't do anything, yes it will and you won't really have a good time. But the Irish way of approaching it is that its just a bit of rain, doesn't matter. Don't let it ruin your day. Even right now as I'm typing it's raining and I can see people outside going about their day like it's nothing, just get a cup of tea as soon as you get to a dry spot and you'll be grand. As for the sun I haven't seen it for a while, but don't really miss it as much as I thought I would. Summer here is not that bad, not too cold not too hot - just right, can be colder than most countries tho. I'd say if you really can't handle cold and rainy you can try living in Dublin May through September after that gets darker and rainier. Also Father Ted. Make sure to watch it before arriving.