Kos weather by month

When to go to Kos

For beach weather, look at months where the daytime average clears 25°C and rainy days stay low: July, August, September. December is the wettest month (181 mm, about 13 rainy days) and July the driest (0 mm). The sea is warmest in August at 25.2°C and coolest in March at 16.4°C.

Getting there

A direct flight from London Gatwick to Kos International Airport "Ippokratis" (KGS, 21 km from Kos) takes roughly 4 h 6 min - short-haul (up to 4.5 h) by UK standards. Time-zone: Europe/Athens.

Records and extremes, 1991-2020

The hottest day recorded in Kos between 1991 and 2020 reached 35.3°C on 1 July 2017; the coldest fell to 1.4°C on 14 February 2004. In August one day in ten tops 30.1°C and about 10% of days pass 30°C; in January one night in ten drops to 7.4°C or below. The wettest single month of the period was December 2012 with 433 mm, against a December average of 181 mm.

Spring: comfortable days, but the sea takes time to warm

Spring becomes much more useful for an outdoor holiday as it progresses. March averages 15°C by day, so bring layers rather than relying on beachwear; the sea is just 16°C. April lifts daytime temperatures to 18°C, comfortable for spending time outside without summer heat, though rain remains a consideration. May offers the clearest shift towards summer, with days at 21°C and only 3 rain days on average. Its catch is the sea: at 19°C, swimming may still feel brisk. Pack a light layer for evenings and choose May if you want sunshine and moderate warmth rather than the warmest water.

Summer: the strongest choice for sunshine and swimming

June, July and August are the strongest choices if sunshine and swimming are your priorities. June averages 25°C by day, with a 22°C sea, making it a good choice if you prefer less heat than later in summer. July and August both average 27°C during the day, but August has the warmer water at 25°C. All these months average 0 rain days, so waterproofs are less of a packing priority than sun protection. Plan shade breaks around midday rather than treating the averages as a limit on the heat. Nights stay warm too, so lightweight evening clothes make sense.

Autumn and winter: lingering warmth, then wetter weather

September keeps much of summer's appeal, with warm days and little rain, while October is particularly useful for travellers who care more about sea warmth than hot afternoons. Its water averages 23°C, warmer than June's, although 5 rain days make flexible plans sensible. November still reaches 19°C by day, but rain becomes a more regular consideration. Winter is a different kind of trip: December averages 16°C by day and has 13 rain days, while January and February sit at 14°C with 12 rain days each. Bring waterproofs and layers, and leave room to change outdoor plans. These months suit mild-weather breaks rather than holidays built around swimming or dependable sunshine.