The first notable autumn rains are expected from next Sunday into early next week, according to forecasters. Until then, the weather remains clear, with temperatures reaching 31°C and winds not exceeding 5 Beaufort.

Thodoris Kolydas explains that the #Alessio storm is the first of the 2025–26 hydrological year for the Central Group of Eumetnet countries. While it will bring very strong winds and severe storms to Italy, it will not affect Greece, as it is moving northeast.

He adds that “we will need another two days to confirm whether the next disturbance, coming from the west next weekend, might affect us. Current forecast models show low probability, and no agreement has yet been reached among them.”

✅H κακοκαιρία #Alessio είναι η πρώτη για τις χώρες του Κεντρικού Group της Eumetnet της περιόδου 2025-26 και θα προκαλέσει στην Ιταλία πολύ ισχυρούς ανέμους και έντονες καταιγίδες. Το σύστημα αυτό δεν θα επηρεάσει τη χώρα μας, καθώς κινείται ΒΑ.
✅Περιμένουμε ακόμη ένα… pic.twitter.com/P4Gy0ntgNk

— Theodoros Kolydas (@KolydasT) September 22, 2025

Clearchos Marousakis analyzes on Facebook how a “Rex” atmospheric blocker may bring the first notable autumn bad weather. He explains:

“The ‘Rex’ blocker may feed back a barometric low around this high-pressure system. On forecast maps, the anticyclone is marked ‘Y,’ spinning air masses clockwise in the Northern Hemisphere, while the barometric low south of it is marked ‘X.’ This combination drives cold air from the mid and upper troposphere toward the low, creating unstable conditions. Combined with our warm seas, this can produce highly unstable and dangerous weather.”

Marousakis adds that early indications suggest effects from this system could be felt from Sunday into early next week. He also highlights the potential rainfall volume, noting that southern Italy could see over 50 mm of precipitation by Saturday night.

Autumn Equinox and Current Conditions

Despite the Autumn Equinox, conditions in Greece remain more reminiscent of summer. Strong winds in the Aegean and persistent drought continue to affect farmers. However, night-time cooling has prevented temperatures from remaining excessively high.

Kolydas notes that changes in atmospheric circulation may bring the first noteworthy autumn rains toward the end of the week, driven by the Rex blocker, an atmospheric circulation pattern studied by meteorologist Daniel Rex. The system works similarly to the familiar Omega block but can feedback a low-pressure system that interacts with surrounding high pressure, generating instability.

Recent Temperatures

Minimum temperatures below 10°C were recorded on Monday, September 22, mainly in northern continental areas and the Lassithi Plateau in Crete. The lowest temperature was 4.2°C in Tzermiado, Lassithi.

Forecast for the Coming Days

Tuesday, September 23 – Sunshine with occasional clouds, especially in the northeast and Crete. Limited visibility in some areas during the morning and evening.

• Northern Greece: 13–29°C (Western Macedonia 10–27°C)
• Central/Southern Greece: 18–31°C
• Western Greece: 14–30°C
• Cyclades/Crete: 18–27°C
• East Aegean: 16–31°C
• Dodecanese: 20–27°C
• Winds: Aegean north 3–4 Beaufort; Ionian variable, light

Wednesday, September 24 – Mostly clear, some clouds in western highlands during midday-afternoon. Winds WNW 3–5 Beaufort. Temperatures largely unchanged, 28–31°C.

Thursday, September 25 – Initially clear. Clouds develop midday in northern areas and continental highlands, with isolated thunderstorms in the Macedonian mountains. Winds north 3–5 Beaufort (Aegean 6–7). Slight temperature drop in the north.

Friday, September 26 – Eastern mainland, Evia, Cyclades, and Crete: cloudy with local rain. Western areas are mostly clear, with afternoon clouds and showers. Winds: west 3–4 Beaufort, east 4–6, Aegean 6–7. Temperatures fall slightly in the east.

Saturday, September 27 – Western mainland and Ionian: increasing clouds with showers and thunderstorms. Northern Aegean: partly cloudy. The rest of the country is mostly clear. Winds: west SSE 4–5, east N 4–6, Aegean locally 7. Temperatures decrease nationwide.