Authorities in Greece are closing the Acropolis in Athens for a second afternoon on Thursday as the country swelters in unseasonably high temperatures.

Greece’s Culture Ministry said the hilltop citadel, which is Greece’s most popular ancient site, will be closed from midday to 5pm (9am-2pm Irish time) because of the heat.

All other archaeological sites in the Greek capital will be closed during the same hours.

People who have booked visits for that period can use their tickets later in the day, the ministry said.

Temperatures are expected to exceed 40 degrees on Thursday in much of central and southern Greece, including greater Athens, the Cyclades islands and Crete.

Officials are on heightened alert for wildfires, which plague Greece every summer.

Authorities in Athens are providing air-conditioned areas for the public and have issued fans to secondary schools where end-of-year and university entrance exams are being held.

Cooler temperatures are expected on Friday and Saturday.