Firefighters in Wales have attended almost 2,000 fires so far over the bank holiday weekend and one brigade has warned that the worst may not be over.
Helicopters have been used to fight the fires
South Wales Fire Service said that since the beginning of April it has received almost as many 999 calls relating to grass fires than it did for the whole of last year.
Since Thursday, the south Wales brigade has attended 1,400 fires after receiving 4,900 calls.
The North Wales Fire Service has dealt with more than 100 fires, while the Mid and West Wales brigade has attended 350 incidents over the bank holiday.
It's been the worst grass fire season since 1976
Helen Cade, South Wales Fire Service
The South Wales brigade said that the continuing dry weather means that more fires could take hold and that it was believed many of the fires were started deliberately.
South Wales Fire Service spokeswoman Helen Cade said crews from the Mid and West Wales, Hereford and Worcester, and Avon brigades had been called in to help put out fires.
She warned that there could be delays in dealing with other fires due to the volume of calls.
"We can't deny there will be delays," she said.
"We could have a house fire or a road accident, and there is likely to be a delay.
"With the kids being off school - who we believe to be the cause of the majority of the fires - and what with the wind, it's been the worst grass fire season since 1976.
Homes were evacuated during the fire at Baglan
"Both police forces in our area are looking to arrest people - it's arson - but they have to catch the culprits first."
In south Wales, firefighters tackled a blaze on either side of the Arrael Mountain, near Abertillery, on Sunday.
A helicopter was called to help fight the fire.
There were also grass fires in Tonypandy, Sarn, Pont-yr-hyl, and Pontycymmer, Pyle and Cwmcarn.
The south Wales brigade said it had received an average of 100 calls per hour since Saturday morning.
Mid and West Wales Fire Service said their crews were continuing to deal with fires in Morriston, Swansea, Port Talbot, Cymmer and Pontardawe.
Fires that raged earlier in the weekend above Baglan, near Port Talbot, and at Wattsville, near Newport, are out.
In Baglan, homes were evacuated as the flames threatened to reach properties.
Police inquiries are also continuing into a scrub fire at Llanbradach, near Caerphilly.
Five people were arrested on suspicion of arson in connection with the blaze and later released.