Broiling temperatures in Japan saw the mercury hit a record 41 degrees Celsius (106 Fahrenheit) on Monday, after at least nine people died from heatstroke over the weekend.

The nation's weather agency issued heat warnings for 38 of Japan's 47 prefectures, telling people to keep hydrated and use their air conditioners.

Sweltering temperatures contributed to the deaths of at least nine people from heatstroke on Saturday and Sunday, Japanese officials and media reports said.

Another heatwave last month claimed at least a dozen lives.

Japan's record temperature Monday was registered at 1:42 pm (0442 GMT) in Shimanto, a Pacific coast city on the western island of Shikoku, the Japan Meteorological Agency said.

That broke the old high of 40.9 degrees Celsius in August 2007 registered in two central Japanese cities, the weather agency said.

Temperatures have soared above 40 degrees Celsius for the third straight day across parts of Japan as a Pacific high-pressure system covered most of the country.

Energy costs have rocketed after Japan shut down its nuclear reactors in the wake of the Fukushima atomic crisis two years ago.

The move forced Tokyo to turn to pricey fossil-fuel alternatives to plug the gap.

In the bustling Tokyo shopping district of Ginza people were trying to guard against the scorching weather.

"I use a special deodorant. When you put it on it feels really fresh straight away. It sells everywhere in Japan," said Takenori Omori, a 27-year-old computer specialist.

Hiroko Mimura, a 63-year-old receptionist, added: "The sun is really strong. I use gloves to avoid getting sunburnt on the hands."

Another shopper, Aya Kida, said she wouldn't try to save electricity any longer, although the Japanese people are encouraged to do so after the 2011 earthquake and tsunami crippled the Fukushima plant, stalling the country's nuclear power generation as a whole.

"It's too hot. The air conditioner is on all day and all night long at home," said the 25-year-old saleswoman.