Island overview
A uniform blanket of cloud sits over Crete on 20 September, with no rain expected anywhere on the island. Temperatures remain solidly late-summer: the coolest spots, Rethymno and Sitia, reach 25.1°C, while the northeast and south push comfortably into the high twenties. This is overcast in the Mediterranean sense – warm, hazy, and still very much beach weather.
North versus south
The south coast is the standout today. Ierapetra (27.8°C) and Makrigialos (28.0°C) sit warmer than the north, and Ag. Nikolaos with Elounda on the northeast corner lead the island at 29.2°C. By contrast, the north-central strip – Rethymno (25.1°C), Hersonissos (25.6°C), Heraklion (26.6°C) – is a few degrees cooler and windier. Chania at 26.2°C falls in the middle, with noticeably lighter winds than elsewhere on the north coast.
Mountains
The White Mountains above Chania and the Psiloritis massif will be significantly cooler than coastal readings today, likely dropping to 10–14°C at altitude. The lower cloud base may reduce visibility on the upper trails. Hikers heading above 1,500 m should carry a windproof layer regardless of how warm it feels at sea level.
Wind, UV and sea state
Wind is the main variable splitting the island today. The east is the breezy end: Sitia tops out at 25.4 km/h, Ag. Nikolaos and Elounda reach 24.7 km/h, and Heraklion 24.4 km/h. These speeds are noticeable on open beaches and will affect small boat excursions. The west and south are calmer: Chania 11.4 km/h, Ierapetra 13.2 km/h, Makrigialos 13.0 km/h. UV is moderate-high across the island, ranging from 6.7 in Heraklion and Sitia to 6.95 in Rethymno. Cloud cover does not eliminate UV risk at these levels. Sea temperatures are still fully summer across the board: 25.4°C at Sitia and Makrigialos, 26.5°C at Heraklion. Waves are gentle on the south coast, with Ierapetra at 0.20 m and Makrigialos at 0.24 m. The north and east are choppier: Sitia reaches 1.04 m, Hersonissos and Malia 0.98 m, Elounda 0.90 m.
Swim verdict
Good conditions for swimming across most of the island. The south coast is the best choice today: flat water, warm sea around 26°C, and light winds. The north-central coast is fine for confident swimmers but expect some chop. Sitia is the least comfortable option today due to the combination of the strongest wind and the highest waves at 1.04 m.
Practical tip
The overcast sky is deceptive. With UV readings between 6.7 and 7, sunburn remains a real risk, particularly between 11:00 and 15:00. Apply SPF 30 or higher before heading to the beach, and reapply after swimming. You will not feel the sun burning, which makes it easier to stay out longer than intended.