March to May: The weather is predictably unpredictable, although April and May are lovely months to start exploring Wales’s coastlines, as the weather warms up (average temperatures around 10–15°C) and the crowds have yet to arrive.
June to August: For much of the summer, Wales – particularly the coast – can be bathed in sunshine and between June and August, the Pembrokeshire coast, washed by the Gulf Stream, can be as warm as anywhere in Britain - the perfect time to lie on a beach or camp in the dry. Superb festivals too. Note, though, that the tops of mountain ranges can still get very cold, even in midsummer.
September to November: Autumn colours take centre stage in September, particularly in Wales' three national parks. However, the weather can be really changeable, so expect sunshine one moment and a torrential downpour the next. Still, with temperatures averaging 8–15°C, it’s ideal for exploring the country’s many castles without the crowds.
December to February: Mornings are frosty, days are short and dark and temperatures hover around 3–7°C, making it a great time to enjoy Wales’ warm and welcoming country pubs. Another attraction is the Christmas markets, particularly in Cardiff and Swansea, which otherwise offer plenty of festive cheer.