TOKYO - Sweltering heat continues across Japan on Monday with the mercury topping 37 degrees Celsius in some areas in the morning, the country's weather agency said.

The Japan Meteorological Agency (JMA) said intense sunshine started driving up temperatures across the country from the morning, with heatstroke alerts having been issued for 39 out of 47 prefectures.

ALSO READ: Japan to experience record heat, extreme temperatures

By 11:30 am local time, the mercury had reached 37.5 degrees Celcius in Daigo Town, Ibaraki Prefecture, 37.4 in Hamamatsu City, Shizuoka Prefecture, and 36.1 in downtown Tokyo, weather agency data showed.

Daytime highs are expected to hit 39 degrees Celcius in Gifu City and Saitama Prefecture's Kumagaya City, and 38 in the cities of Saitama and Nagoya, the JMA added.

READ MORE: Record summer heat scorches many parts of Japan

Weather officials urged people to take thorough protective measures, such as avoiding outings as much as possible and staying in a cool indoor space.