Temperatures will start to fall sharply in Greece from Tuesday, dropping as much as 9 degrees below normal for this time of year by Thursday, according to the National Observatory of Athens weather service METEO.
Temperatures on Tuesday will remain high for this time of year in central and southern parts of the country but will start to drop in the north to normal levels for September.
Cold masses of air now above central Europe will start to push southward on Wednesday and affect central and northern parts of the country.
Most of the country will be affected on Thursday and temperatures will drop by as many as 9 degrees below the normal levels for this month.
The phenomenon will be short-lived, however, with the mercury rising again from Friday and only remaining below average for the season in eastern parts of the country, while there will be a further rise in temperatures at the weekend.