Temperatures are expected to top 30 degrees Celsius on Wednesday in many parts of Japan. Weather officials are calling on people to exercise caution against heatstroke.

A high-pressure system covered the country on Tuesday. Some areas had high temperatures not usually seen until June or July.

The daytime high reached 32.1 degrees in a town in the southern prefecture of Miyazaki. Central Tokyo recorded 27.5 degrees.

The Meteorological Agency says the high-pressure system will continue to cover many parts of the country on Wednesday.

The agency says it's going to get even hotter, mainly in eastern and northern Japan.

Officials say the foehn phenomenon, in which dry winds coming down from mountains push up temperatures, will also be a factor.

Maebashi City north of Tokyo will see a daytime high of 36 degrees, while central Tokyo will warm up to 31 degrees.

Officials are calling on people to be careful about heatstroke. They recommend staying hydrated and using air conditioners to keep room temperatures at 28 degrees or lower.