A new heat wave is expected to hit Greece from Thursday, with temperatures rising to 40 Celsius.

The hot spell is forecast to last for five days, according to the National Meteorological Service (EMY). In Athens, temperatures will reach a high of 40 Celsius, while in Thessaloniki they will climb to 39 Celsius.

According to data collected by the National Meteorological Service, this June was the third-hottest on record. The average high -- as recorded at the weather station in the Athens suburb of Nea Philadelphia -- was 34.6 Celsius, which is more than 3 degrees above the seasonal average.

The only two times in recent years that the temperature was substantially above the seasonal average in June was in 2003 and 2007, when the top temperatures reached an average high of 33.3 and 33.9 respectively.

July also set new records as the average high was 37.2 Celsius, compared to a seasonal average of 33.4 degrees. Until this year, the warmest months of July were in 1998 and 2000, when the average top temperatures were at 36.2 and 36.5 degrees.

The highest temperature recorded in Greece this year was in July, in Sparta and Tripoli, where it reached 43 Celsius.