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 →

Kos🇬🇷 Greece · Greece & Cyprus · Island93
  1. 54Jan
  2. 65Feb
  3. 72Mar
  4. 78Apr
  5. 83May
  6. 91Jun
  7. 88Jul
  8. 90Aug
  9. 93Sep
  10. 87Oct
  11. 70Nov
  12. 57Dec

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, Greece
Photo: Wolfgang Weiser · Pexels

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.

MonthScoreTierHighRainSunCrowdsOn
Jan54D15°C14 d8 hBusy1
Feb65C16°C10 d9 hBusy2
Mar72B17°C8 d10 hBusy3
Apr78B20°C4 d11 hPeak1
May83A24°C3 d13 hBusy2
Jun91S29°C1 d14 hPeak3
Jul88A31°C0 d13 hPeak3
Aug90S31°C0 d13 hPeak3
Sep93S29°C1 d11 hPeak3
Oct87A25°C3 d10 hPeak3
Nov70B21°C10 d8 hShoulder1
Dec57D17°C14 d8 hBusy1

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

Everything on in Kos through the year →

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)

JFMAMJJASOND

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.
Discover Greece · Read the original ↗

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.
Tripadvisor community · March · 1 month ago · Read more on Tripadvisor ↗
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.
Tripadvisor community · September · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Kos's card on the map.