I like Ireland around the autumn equinox. The weather...well, it can rain any day during any season, and September-October is not exclusion :) It's warm enough to go hiking (uufffff, the green landscapes!), and no matter the weather, you can always drink a pint of Guinness beer in one of the Irish pubs. Check some seasonal info on
rove.me and
Vagabond Tours, and you will see how many great things await you there in autumn!