Winds dropped to about 5 mph despite earlier forecasts of violent gusts, easing fears that smoldering embers left by this week's fires in the Var region would re-ignite.
Nearly 1,000 firefighters from across France, Spain and Greece were drafted in to relieve their exhausted colleagues, many of whom have been battling the flames around the clock since Monday.
Thousands of acres of pine forests and scrubland have been scorched. The risk of further fires, however, still remains ``severe'' Friday, Frances's Civil Security unit said.
Many roads bordering forests remain closed to the public while dozens of police patrols have been deployed to thwart possible arsonists. Police suspect the fires were deliberately set.
A hail storm lasting one and a half hours thankfully moistened a region that has been stricken by drought over the last two months, said local firefighter spokesman Florian Denan. ``Humidity levels have greatly increased,'' he said.
Investigators, meanwhile, kept up a search for arsonists after the discovery of three Molotov cocktails near one of the Riviera fires.
Four foreign tourists _ two British, a Dutch and a Polish citizen _ were killed in the blazes that officials say were the worst in decades.
One man has been placed under investigation for allegedly setting seven fires in the region since July 5, but Draguignan Deputy Prosecutor Michel Raffin said he was not a suspect in this week's fires.
Stephane Jousse, 29, of Figanieres, was arrested hours before Monday's blazes erupted, ``which would have made his participating in the three major fires impossible,'' Raffin said.
Authorities were preparing to interrogate other suspects, Raffin added, without giving details. Two people taken in for questioning on Wednesday have been released, he said.
President Jacques Chirac has vowed to punish any possible perpetrators behind the forest fires.
The fires have left a swath of blackened moonscape across the craggy, brush-covered hills in the tourist-filled area of the Mediterranean coast.