The recent spell of hot weather in the canton, with little rain, has led to a “marked risk” of wildfires in some areas of the Valais, cantonal authorities said in a statement.
“In the last few days there have unfortunately been several small brushfires,” it said, adding that forested and grassy areas “can catch fire quickly when very dry”.
The arrival of storms forecast in the following days also raises the chance of forest fires, it said.
People should take “great care” when using fireworks around the time of the country's National Day celebrations this weekend and on Monday, said the authorities.
“Fires and fireworks will only be tolerated in areas designated and secured by the communes,” it said. “In every instance a fire should be watched and extinguished before being abandoned.”
Communes all over the country stage fireworks displays to celebrate Swiss National Day, while bonfires are traditionally lit on hilltops to commemorate a communication method dating back to the 14th century.
Last summer the canton and many others in Switzerland placed a ban on campfires, barbecues and fireworks in wooded areas due to an elevated risk of forest fires, which put a damper on National Day celebrations.
And the mild, dry Christmas period saw many parts of the country impose bans or restrictions on fireworks, causing several big New Year's Eve fireworks displays to be cancelled.
There are currently no outright bans on fires in the Valais, though people are advised not to light barbecues outside designated areas.
According to Meteo Suisse, Switzerland should enjoy a hot and mainly sunny Saturday before storms hit on Sunday.
July has been characterized by hot, sunny weather and violent storms, with temperatures on average one degree higher than normal, it said.
Source: Meteo Suisse