The mercury soared Sunday to 36.1 degrees in Inukai, Oita Prefecture, and record highs for May were recorded from Okinawa to Kanagawa Prefecture, the Meteorological Agency said.

Inukai became the first location to experience an "extremely hot day," a new category introduced by the agency in April to describe a day when the mercury tops 35.

The previous highest May temperature in Inukai was 33.2, marked May 26, 1991.

Other locations where temperatures broke May records included Odawara, Kanagawa Prefecture; Kumano, Mie Prefecture; Misho, Ehime Prefecture; Sukumo, Kochi Prefecture; Shibushi, Kagoshima Prefecture; and Kumejima, Okinawa.

Warm air has streamed across the archipelago from the south since Saturday, the weather agency said.