Weather in Kos in August

How August compares

August is the 1st warmest month of the year in Kos and ranks 98th of 134 destinations we compare for August - see where else is hot in August. Within Greece it is 34th of 44 (Greece in August). Against London's average high of 21.4°C in August, Kos is 6.0°C warmer by day and 11.1°C warmer at night.

Daytime and night-time in August

The typical August day in Kos peaks at 27.4°C, but that is an average: the warmest 10% of days reach 30.1°C or more. About 94% of days top 25°C and 1 in 10 pass 30°C. Nights average 24.6°C; one night in ten drops to 23.0°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest August day here reached 34.5°C (2019-08-24) and the coldest night 20.0°C (1997-08-21).

Rain in August

Dry (3 rainy days or fewer): about 0 days with 1 mm or more, 0 mm in total. Year to year it varies a lot - the wettest August was 1995 with 1 mm, the driest 1991 with 0 mm. Humidity averages 73%.

Sea temperature in August

The sea averages 25.2°C - warm enough to swim (22°c+). Depending on the year it ranges from 24.0°C to 25.9°C. This is the warmest the sea gets here all year.

Sunshine and daylight

Around 13.2 hours of sunshine a day (estimated from cloud cover), 13.4 hours of daylight: the sun rises about 06:28 and sets about 20:03 local time in mid-August. Average cloud cover is 2%.

Is August a good time to visit Kos?

Yes - it is one of the better months: hot days, little rain and long sunny days. The best months for Kos on our scoring are August, July, June; months averaging 25°C or more: Jul, Aug, Sep.

Expect warmth that lasts into the evening

August's heat is persistent rather than routinely extreme: 94% of days reach 25°C, while 10% reach 30°C. That makes light, breathable clothing the sensible default, with outdoor plans better placed in the morning or later in the day if you dislike midday heat. Humidity averages 73%, so the temperature alone may understate how warm it feels. Evenings offer little cooling, and you are more likely to want loose clothing than a substantial extra layer. Air conditioning is a sensible accommodation priority, especially if warm bedrooms disturb your sleep. This is a less comfortable choice for travellers who prefer crisp nights or energetic outings through the middle of the day.

Good swimming weather, with shade still important

The sea is firmly in comfortable swimming territory at 25.2°C, with a year-to-year range of 24°C to 26°C. That makes August a good fit if swimming is central to your holiday rather than something you hope to brave briefly. Sunshine averages about 13.2 hours a day, leaving plenty of scope to spread outdoor time around breaks indoors or in shade. Rain is unlikely to shape your plans, but dry weather does not make continuous sun exposure comfortable. Pack sun protection and light cover-ups, and plan somewhere shaded for the hottest part of the day. The appeal here is dependable warmth; the trade-off is limited respite from it.