Kos weather by month
The best time to visit Kos is June, August and September — 93/100 in September, 29°C and 1 rainy day. The best season is summer, June to August (90/100 on average).
The worst month is January at 54/100 — cool, soaked, clean air. See January →
Updated September 2026 · climate normals from ERA5 reanalysis
Planning the wider trip? Best time to visit Greece →
Best season: June to August (90/100 on average) · worst January (54/100)
- Days
- 29°C
- Nights
- 23°C
- Wet days
- 1
- Sun
- 11.4 h
- Humidity
- 72%
- Daylight
- 12 h

Kos, month by month
Comfort score out of 100 for the kind of trip Kos is best for, the average high, rainy days and hours of sun a day from the climate normals, and how busy it tends to be.
What's on in Kos through the year
Festivals, natural spectacles, holidays and the seasons to watch out for — curated and sourced. The month pages carry the detail.
- February
- Clean Monday23 FebHoliday
- March
- Independence Day25 MarHoliday
- April
- Orthodox Easter10–13 AprHoliday
- May
- Charter and resort season1 May – 15 Oct (usually)Season
- June
- Sea warm enough15 Jun – 31 Oct (usually)Season
- Meltemi15 Jun – 15 Sep (usually)Season
- October
- Ohi Day28 OctHoliday
- November
- Winter shutdown1 Nov – 31 MarSeason
Crowds in Kos in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Peak crowdsCharter and resort season, Summer holidays in Greece, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Good to know before you go to Kos
Real experiences from travellers' own write-ups, quoted with a link to the original.
Getting around
A guide to getting around Kos highlights the 13km cycle path running along the waterfront and through side streets of the main town, which combined with the island's flat terrain makes biking a genuinely practical way to get around, not just a tourist activity, with rental agencies widely available. Their advice for visiting the archaeological sites, including the Castle of Neratzia and the ancient plane tree where Hippocrates reportedly taught: go early, between 8 and 9am, to beat both the tour groups and the midday heat.
Traveller notes on Kos
What people who have been say about the place — the year-round notes first, then month by month.
Forum posters describe March in Kos as genuinely unpredictable but still mild overall, sitting outside the reliably hot, dry stretch that runs roughly June through early October. Posters note showers this time of year can affect one side of the island while leaving another completely dry, reflecting how localized spring weather patterns can be here. Posters consistently recommend packing layers and a light raincoat for a March visit, ready for both sunny stretches and passing rain within the same trip. Posters generally rate March as a mild, changeable shoulder-season month for Kos, well ahead of the settled summer heat but past the harshest of the Aegean winter.
September is the month Kos regulars call the best of the year — 25 to 30°C, the sea still at 27°C, everything open, and nowhere near July and August's crowds. Evenings want a cardigan. The thing to understand about the wind is that it is directional rather than seasonal: the meltemi is a northerly running June to about mid-September, so it hits the north coast hardest — Tigaki and Mastihari especially — and the forum's fix is simply to switch sides of the island, Kardamena being the usual suggestion. Kos reads breezy year-round on the monthly averages, but an average smooths over exactly the local, directional effect regulars are describing, so take the coast advice over the number. In the heat most people count it a cooling breeze rather than a problem.
Add your own note from Kos's card on the map.