The fires in Spain this year have burned 158,000 hectares or 610 square miles, according to the European Union’s European Forest Fire Information System. That is an area roughly as big as metropolitan London.

Spain’s national weather agency warned of extreme fire risk in most of Spain, including where the largest blazes were burning in the north and west.

Firefighters have spent days battling blazes in Greece, Portugal, Spain and elsewhere. Forecasters said temperatures could pass 111 degrees in some places on Thursday.