24-hour weather system to bring thunderstorms and lightning – When severe weather will hit Attica

A significant change in weather conditions is expected across most of Greece from around midday on Friday, July 24, through midday on Saturday, July 25, with heavy rain and thunderstorms forecast to impact many regions.

According to an emergency weather deterioration bulletin issued by the Hellenic National Meteorological Service (EMY), the storms will be accompanied in many areas by strong wind gusts (squalls), frequent lightning, and a risk of localized hail.

Meteorologist Theodoris Kolydas said the most intense weather is expected to affect:

• Central Macedonia
• Eastern Thessaly and Magnesia
• The Sporades islands
• Central and northern Evia (Euboea)
• Eastern Central Greece, including Attica
• Parts of the northeastern Aegean

Authorities are urging extra caution in coastal and marine areas, where thunderstorms may bring sudden squalls and rapid increases in wind speeds.

“Anyone planning boating, fishing, sea excursions, or other marine activities on Friday afternoon or Saturday should consider postponing them. Conditions may change rapidly, particularly in the Sporades, Evia, Magnesia, the northeastern Aegean, and other coastal areas affected by the storms,” Kolydas, the former director of EMY, warned.

Areas under severe weather alerts

According to EMY, heavy rain and thunderstorms are expected as follows:

Friday, July 24

• Central Macedonia (Pieria, Imathia, Halkidiki, and Thessaloniki): From late morning until late evening (Orange Warning).
• Eastern Thessaly (Larissa and Magnesia): From midday until late at night (Orange Warning), with Red Warning conditions expected mainly in coastal and marine areas.
• Sporades and Evia (especially central and northern parts): From midday onward (Red Warning).
• Eastern Central Greece, including Attica: From the afternoon until late evening (Orange Warning).
• Northeastern Aegean islands (Lemnos, Thassos, and Samothrace): From late evening (Orange Warning).

Saturday, July 25

• Sporades: Until the morning (Red Warning).
• Evia: Especially central and northern areas, until late morning (Red Warning).
• Northeastern Aegean islands (Lemnos, Thassos, Samothrace): Until the early morning (Orange Warning).
• Magnesia, mainly eastern coastal areas: Until the early hours (Orange Warning).

Eleven regions placed on Red Code alert

In response to the expected severe weather, Greece’s Risk Assessment Committee met on Thursday afternoon. The General Secretariat for Civil Protection has placed 11 regions on heightened readiness (“Red Code”) for Friday, including:

• The Region of Attica
• Thessaloniki, Pieria, Imathia, and Halkidiki regional units (Central Macedonia)
• Larissa and Magnesia regional units, including the Sporades (Thessaly)
• The Region of Central Greece
• Thassos and Samothrace (Eastern Macedonia and Thrace)
• Lemnos (North Aegean)

Forecast for Friday, July 24

Weather conditions will deteriorate first across western and northern Greece before spreading to the rest of the country, bringing widespread showers and thunderstorms.

The strongest storms are expected in:

• Central Macedonia
• Eastern Thessaly
• The Sporades
• Evia
• Eastern Central Greece, including Attica
• Northeastern Aegean islands

Conditions are expected to gradually improve in western Greece from Friday evening onward.

North winds of 4-6 Beaufort are forecast, reaching 7 Beaufort locally over the Ionian Sea and the southeastern Aegean.

Temperatures will fall slightly, reaching:

• 29-30°C (84-86°F) in northern Greece
• 30-32°C (86-90°F) across most other regions
• Around 33°C (91°F) in Crete and the Dodecanese

Attica forecast

Attica will start the day with partly cloudy skies before cloud cover rapidly increases. Rain and scattered thunderstorms are expected to develop, becoming locally severe from the afternoon through late evening.

Winds will initially be light and variable at 3-4 Beaufort, turning northerly by evening at up to 5 Beaufort.

Temperatures will range between 22°C (72°F) and 30°C (86°F).

Thessaloniki forecast

Cloudy skies with rain and scattered thunderstorms are expected, with locally severe storms from late morning through the afternoon.

Winds will shift from light variable to northwesterly at 4-6 Beaufort.

Temperatures will range between 20°C (68°F) and 28°C (82°F).

Outlook for Saturday, July 25

Eastern mainland Greece and the Aegean will continue to experience showers and thunderstorms until the afternoon, with severe weather lingering into the morning over the Sporades, Evia, parts of Magnesia, and the northeastern Aegean islands.

Elsewhere, conditions will be mostly sunny with only brief afternoon cloud development inland.

North winds of 4-6 Beaufort, reaching 7 Beaufort in parts of the Aegean, are expected.

Temperatures will fall slightly, with highs generally between 26°C (79°F) and 30°C (86°F).

Outlook for Sunday, July 26

Weather conditions will improve significantly, with mostly sunny skies across the country. Only isolated afternoon cloud development is expected over northern mainland areas.

North winds of 3-5 Beaufort will prevail, reaching 6-7 Beaufort in parts of the southeastern Aegean. Southerly winds will gradually develop over the Ionian Sea and the western Aegean later in the day.

Temperatures are expected to rise slightly.