Kos
Greece · Europe
The best time to visit Kos is May, June, July, August, September, and October. In summer, daytime highs average 32°C (90°F), with peaks around 36°C (97°F); in winter, nights average 9°C (48°F), dropping to around 1°C (34°F) on the coldest. During the best travel months, the sun shines up to 12 hours per day — ideal for sightseeing and outdoor activities.
Kos – What you should know
Kos is the second most visited Greek Aegean island after Rhodes and offers a reliable summer climate: from May to October over 10 hours of sunshine daily, barely any rain and water temperatures of 22–26°C (72–79°F). Like Mykonos, Kos benefits from the Meltemi, which limits the midday heat of 28–31°C (82–88°F) in July and August to manageable temperatures.
High season runs from June to September. May and October offer quieter conditions at 22–25°C (72–77°F) — ideal for cycling through the olive groves for which Kos is famous. In April the island blooms in full vegetation before the first tourist rush begins.
Climate Overview
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Ø day, range from coolest to warmest dayØ dayrange | 15° (59°)7– (45–)18 (64) | 15° (59°)8– (46–)18 (64) | 17° (63°)12– (54–)21 (70) | 20° (68°)15– (59–)26 (79) | 25° (77°)19– (66–)30 (86) | 29° (84°)24– (75–)34 (93) | 32° (90°)28– (82–)36 (97) | 32° (90°)28– (82–)36 (97) | 29° (84°)24– (75–)34 (93) | 24° (75°)18– (64–)28 (82) | 20° (68°)14– (57–)25 (77) | 16° (61°)9– (48–)21 (70) |
Ø night, range from coldest to warmest nightØ nightrange | 9° (48°)1– (34–)15 (59) | 10° (50°)2– (36–)14 (57) | 11° (52°)2– (36–)15 (59) | 14° (57°)8– (46–)17 (63) | 17° (63°)12– (54–)20 (68) | 21° (70°)17– (63–)25 (77) | 23° (73°)20– (68–)26 (79) | 24° (75°)20– (68–)26 (79) | 21° (70°)16– (61–)24 (75) | 18° (64°)12– (54–)21 (70) | 14° (57°)6– (43–)19 (66) | 11° (52°)3– (37–)16 (61) |
☀️Sunshine | 6h UV 5 | 8h UV 6 | 9h UV 7 | 11h UV 9 | 12h UV 9 | 13h UV 10 | 13h UV 10 | 12h UV 9 | 11h UV 8 | 9h UV 6 | 7h UV 5 | 6h UV 4 |
🌊Water Temp | 18° (64°) | 17° (63°) | 17° (63°) | 18° (64°) | 20° (68°) | 23° (73°) | 24° (75°) | 26° (79°) | 25° (77°) | 24° (75°) | 22° (72°) | 20° (68°) |
🌧Rain Days | 9d89mm (3.5") | 5d68mm (2.7") | 5d61mm (2.4") | 1d7mm (0.3") | 2d23mm (0.9") | 0d2mm (0.1") | 0d0mm (0") | 0d0mm (<0.1") | 1d12mm (0.5") | 2d22mm (0.9") | 4d45mm (1.8") | 8d85mm (3.3") |
Best travel timeØ = average · small figures = range: coolest–warmest day / coldest–warmest nightClimate data 2005–2025 · Source: ERA5 + station data
Travel Tips
From April to August, UV levels in Kos reach 10 — very high on the WHO scale. High-SPF sunscreen and shade around midday are essential.
April offers great weather in Kos with fewer tourists and lower prices — ideal for those who want to avoid the peak season crowds.
The travel year in Kos
December – March
Winter on a Greek island: mild at 14 to 16°C (57 to 61°F), but much of it closed. Kos Town carries on because people live here year-round — you get the Asklepieion and the Plane Tree of Hippocrates practically to yourself.
April – May
The island is greener than ever and scattered with poppies. Kos is flat, which makes it the cycling island of the Aegean — in spring you ride the coast roads without heat and without traffic. First swimmers; the water is still 17 to 20°C (63 to 68°F).
June – September
High season with the Meltemi. The north wind makes 31°C (88°F) bearable and turns Kefalos in the west into a kite spot, while the sheltered southern bays stay calm. Practically zero rain days from June to September.
October – November
The water still holds 21 to 23°C (70 to 73°F) while the air turns pleasant. Charter flights thin out and the tavernas in hillside Zia fill with locals again. From November the beach hotels close.
Events & Festivals
June
- Hippocratia Festival· June to October (cultural programme)
A cultural summer in honour of Hippocrates, the father of medicine, who was born on Kos. Concerts, theatre, art exhibitions and the traditional Hippocratic Oath under the plane tree in Kos Town, where Hippocrates is said to have taught.
August
- Honey Harvest Festival (Antimachia)· first Saturday after the Assumption (15 August)
In the mountain village of Antimachia everything revolves around the island's famous thyme honey: local beekeepers present their products, honey specialities are handed out and traditional music accompanies the festivities.
Frequently Asked Questions
- When is the best time to visit Kos?
- The best time to visit Kos is May, June, July, August, September, and October. These months offer the most favourable combination of sunshine, temperatures, and low rainfall.
- How warm does it get in Kos?
- In summer, daytime highs in Kos average 32°C (90°F), with peaks around 36°C (97°F); in winter, nights average 9°C (48°F), dropping to around 1°C (34°F) on the coldest.
- How much rain does Kos get?
- Kos has a relatively even rainfall pattern with an average of 3 rain days per month. The driest months are June, July, and August.
- How warm is the water in Kos?
- Water temperature in Kos ranges from 17°C (63°F) (March) to 26°C (79°F) (August). During the best travel months (May, June, July, August, September, and October), the water is most pleasant for swimming.
Best Travel Time by Vacation Type
🏖️
Beach Holiday
Warm, sunny, little rain
JunJulSep
🏙️
City Trip
Pleasantly mild, not too hot
AprMayOct
