Wildfires over the weekend also affected Hampshire, Durham, West Sussex, East Sussex, Devon and Somerset.
In Wales, the major incident declared over the Conwy wildfire has now been brought under control, according to North Wales Fire and Rescue Service assistant chief fire officer Justin Evans.
But firefighters are still tackling several active blazes, including in Braichmelyn forestry near Bethesda and the Rhinogydd mountain range near Harlech.
Farmer Gareth Wyn Jones, whose land borders the Conwy Mountain, said he had “never seen anything of that scale”.
“It was unreal,” he said, adding that while ponies grazing on the mountain had escaped, he feared for a neighbour’s pigs as flames swept through surrounding land.
“The biggest worry was that they were going to suffocate in the smoke, but the smoke did carry over them,” he said, confirming the animals had survived.
Elsewhere, firefighters remain at the scene of a major moorland fire at Tintwistle Moor near Dovestone Reservoir in the Peak District.
Around 30 to 40 firefighters are continuing to tackle the blaze, which began on 24 June and has burned around 260 hectares (642 acres) of moorland and woodland.
Greater Manchester Fire and Rescue Service senior fire chief Ben Levy warned crews faced “a very challenging and gruelling day ahead” as high temperatures, strong winds and dry conditions continued to fuel the fire.
He urged people to take extra care in the countryside to reduce the risk of further wildfires.
A 20-year-old woman was arrested on Monday on suspicion of arson after police received reports of fireworks being let off in the area.