Heavy rain and strong winds – Red Alert in 9 regions
According to the new information, heavy rainfall and severe thunderstorms are expected from Thursday (December 4, 2025) until early Saturday (December 6, 2025) across most areas in the eastern — and especially the southern — parts of the country.
The weather system named BYRON is expected to bring particularly severe conditions on Friday (December 5, 2025), affecting much of the eastern mainland and island regions. Rainfall will not only be very intense but also long-lasting.
In many areas, the storms will be accompanied by localized hail and, at times, very strong winds. On Friday (December 5, 2025), wind speeds in the southeastern island regions may reach 8 and possibly temporarily 9 Beaufort.
A. Thursday, December 4, 2025
Locally heavy rain and thunderstorms are expected in:
a. The Ionian Islands (mainly Cephalonia and Zakynthos)
b. Central Macedonia (mainly Halkidiki, Pieria, Imathia)
c. Thessaly (especially the eastern parts) and the Sporades
d. Eastern Central Greece (including Attica, mainly the southern and eastern sectors)
e. Evia (mainly the southern parts)
f. The Peloponnese (mainly the southern and eastern parts)
g. The Cyclades
h. Crete (mainly the southern parts)
i. The eastern Aegean islands (from Chios and further south) and the Dodecanese
B. Friday, December 5, 2025 – Impact of Weather System “BYRON”
The system BYRON will bring severe weather conditions to most of the eastern part of the country.
Heavy rain and thunderstorms are expected in:
a. Central Macedonia
b. Thessaly and the Sporades
c. Eastern Central Greece (including Attica) and Evia
d. Eastern and southern Peloponnese
e. The Cyclades and Crete
f. The eastern Aegean islands (from southern Chios downward) and the Dodecanese
Nine Regions on Red Alert
The General Secretariat of Civil Protection has placed nine regions on Red Code alert from today until Saturday, December 6, 2025.
The regions are:
Attica
Thessaly
Peloponnese
North Aegean
South Aegean (with special attention to Thira and Rhodes)
Crete
Central Macedonia (with special attention to Pieria, Imathia, Halkidiki, and Thessaloniki)
Central Greece
Ionian Islands
