Derek Brockway kicks off the series in Gwynedd with a stunning ten-mile walk that starts and ends in Penryndeudreath near Porthmadog. His route follows part of the Ffestiniog railway line with a stopping point at Tan-y-Bwlch station. He learns about the industrialist who changed the landscape and takes shelter from the rain in a farmhouse kitchen, before exploring a Celtic rainforest. Meanwhile, Dr Jeni Millard visits a slate quarry now used to mature cheese, and Onkar Singh Purewal discovers the story of gardener John Ystumllyn, the first recorded black person in north Wales.

Wales’s favourite weatherman, Derek Brockway, visits Usk, winner of the Wales in Bloom gold award an amazing 30 times. His walk is a stunning ten-mile circuit which starts and ends at Usk castle. Derek sees the landscape from above as he hitches a ride in a glider, learns about an ancient orchard, visits some community allotments and helps local youngsters plant sunflowers. Archaeologist Dr Erin Lloyd Jones finds out what the Romans did for Wales, and Matthew Bassett explores decorative oriental-inspired tinware once made in the town.

Derek and the team travel to the point where the counties of Carmarthenshire, Pembrokeshire and Ceredigion all meet to follow the course of the River Teifi between Cenarth and Cilgerran. On the way, Derek learns to steer a coracle, the area’s ancient form of fishing boat, and takes part in the annual coracle races. Meanwhile, Matt Bassett visits possibly the prettiest producers’ market on the Teifi estuary, and Dr Jeni Millard discovers the story of Wales’s smallest museum.

Weatherman Derek Brockway is in Dinas Powys, just outside Cardiff, to walk the five-mile Salmon Leaps circular trail. The route takes him through ancient woodland and across the historical Cwrt yr Ala estate before he returns to Dinas Powys where the village show is in full swing. Wildlife expert Lizzie Daly goes in search of night creatures, and Onkar Singh Purewal joins some dawn dippers in the sea at Penarth.

'Derek the Weatherman’ hopes it will be warm when he takes part in the World Bog Snorkelling championships in mid Wales. It’s at the end of his walk that follows part of the trail along the Heart of Wales Railway, starting in Llandovery. On his way, he takes part in a tug-of-war with young farmers and has afternoon tea under an impressive railway viaduct. Matthew Bassett joins cyclists in Llandovery, and wildlife expert Lizzie Daly goes in search of pied flycatchers in rare Atlantic oak woodland.

Weatherman Derek Brockway visits Rhondda Cynon Taf for a seven mile circular trail that starts and ends in Hirwaun. On his route, he learns about the area’s industrial past, visits a whisky distillery and takes a ride on the world’s fastest seated zipline. Wildlife expert Lizzie Daly investigates how otters are under threat and Onkar Singh Purewal goes on a trek with alpacas across the Brecon Beacons.

Derek and the team travel to the Elan Valley in Powys for a stunning seven-mile circular walk, punctuated by dams. He learns how the valley was flooded to supply water to Birmingham. On his way round, he has a go at mountain biking and discovers the part the area played in the daring Dambusters attack in World War Two. Archaeologist Dr Erin Lloyd Jones visit the ruins of the ancient abbey at Strata Florida, and performer Jonny Cotsen meets military veterans who are being inspired and helped through art.