The World Weather Attribution group of scientists stated that the extreme temperatures recorded in June would have been virtually impossible without the climate crisis.
Temperatures are forecast to climb again this week, rising to 40C locally.
"Climate change is here, we are living the consequences and it is only the start of July," said the fire chief for Pyrénées-Orientales, Eric Belgioino.
"This season is going to be a long one for the soldiers fighting fires. You have to help us."
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Tour de France Restrictions
The regional prefect, Pierre Regnault de la Mothe, ordered Tour de France spectators "not to go near the route or to the finish area" of Monday's third stage of the cycling race through the Pyrenees from Spain into France.
He said it would be "limited to the passage of the riders only and vehicles essential to the race".
On the Spanish side of the border, fire has ravaged 2,200 hectares, with 97% of the damage occurring in the protected natural area of Les Gavarres.
The head of operations of the Catalan fire service, Eduard Martinez, reported that the blaze had a perimeter of 40km (25 miles).
Firefighters said their efforts would be complicated by rising temperatures and the many "smoking hotspots" within the perimeter, but announced late on Sunday that the blaze was stable and they hoped it should be extinguished during the week.
South of Catalonia, in Spain's eastern Castellón province, more than 500 people were evacuated after a wildfire spread into the Sierra de Espadán national park.
