Kos Weather

Kos is the third largest and second most-populated island among the Dodecanese Complex. It boasts a warm and humid climate, similar to its neighboring islands! Wintertime in Kos is rainy and a little bit on the cold side, but its summers are hot and dry, with temperatures rising above 35°C/95°F.

In brief, temperatures and heatwaves peak during August and July. On the other hand, it is not a preferred destination during winter, given that most establishments are shut down for the season, and its temperatures are not ideal for a swim. Most accommodation options, besides some in Kos Town, are open from May to October.
Note that the island is excellent for an early autumn visit, with its water temperature still at a warm enough level!

Below, you can see the average temperatures in Kos by month. We have also gathered information regarding the weather by month.

Average High & Low Air Temperature (in °C/°F)

 

Discover the weather in Kos by month:
January | February | March | April | May | June | July | August | September | October | November | December

Starting off the year, January is quite cold (usually the coldest time of year) with little sunshine, while humidity is at a high level.

The average temperature is 12°C/53.6°F (maximum 15.4°C/59.7°F | minimum 9°C/48.2°F)
On the coldest nights, the temperature may drop to 6°C/42.8°F.
On the warmest days, the temperature may reach 21°C/69.8°F.
The sunshine lasts approximately 5 hours.
Humidity reaches 70%, while the mean speed of the wind is around 8.9 kph (5.5 mph).
The mean sea temperature is about 17°C/62.6°F; hence, the waters are quite cool.

In February, it is still cold with lots of rainfalls, low-temperature sea waters, and a humid environment.

The average temperature is 13°C/55.4°F (maximum: 15.5°C/59.9°F | minimum 10°C/50°F).
On the coldest nights, the temperature may drop to 3°C/37.4°F.
On the warmest days, the temperature may reach 21°C/69.8°F.
The sunshine lasts approximately 5 hours.
Humidity reaches 71%, while the mean speed of the wind is around 9.2 kph (5.7 mph).
The mean sea temperature is about 16°C/60.8°F; hence, swimming is not recommended.

With a few more hours of sunshine per day, March signals the end of wintertime while still being a chilly month with cold breezes during its evenings.

The average temperature is 15°C/59°F (maximum 18.1°C/64.6°F | minimum 11°C/51.8°F).
On the coldest nights, the temperature may drop to 5°C/41°F.
On the warmest days, the temperature may reach 27°C/80.6°F.
The sunshine lasts approximately 7 hours.
Humidity reaches 68%, while the mean speed of the wind is around 8.7 kph (5.4 mph).
The mean sea temperature is about 16°C/60.8°F; hence, swimming is not recommended.

April is the very start of the tourist season in Kos, with a mildly warm climate, though the sea waters are still cold.

The average temperature is 18°C/64.4°F (maximum 21.4°C/70.5°F | minimum 13°C/55.4°F).
On the coldest nights, the temperature may drop to 10°C/50°F.
On the warmest days, the temperature may reach 26°C/78.8°F.
The sunshine lasts approximately 8 hours.
Humidity reaches 66%, while the mean speed of the wind is around 7.4 kph (4.6 mph).
The mean sea temperature is about 17°C/62.6°F; hence, the waters are quite cool.

May opens the floodgates to mass tourism in Kos, with a vast majority of its accommodations opening and preparing their premises for visitors!

The average temperature is 22°C/71.6°F (maximum: 26.6°C/79.9°F | minimum: 17°C/62.6°F).
On the coldest nights, the temperature may drop to 13°C/55.4°F.
On the warmest days, the temperature may reach 32°C/89.6°F.
The sunshine lasts approximately 10 hours.
Humidity reaches 66%, while the mean speed of the wind is around 6.8 kph (4.2 mph).
The mean sea temperature is about 19°C/66.2°F; hence, the waters are a bit cool.

June in Kos is one of the warmest months, with the temperature reaching well over 30°C/86°F and sea waters getting warmer and warmer.

The average temperature is 27°C/80.6°F (maximum 32.1°C/89.8°F | minimum 21°C/69.8°F).
On the coldest nights, the temperature may drop to 18°C/64.4°F.
On the warmest days, the temperature may reach 38°C/100.4°F.
The sunshine lasts approximately 11 hours.
Humidity reaches 64%, while the mean speed of the wind is around 8.4 kph (5.2 mph).
The mean sea temperature is 22°C/71.6°F; hence, the waters are a little warm.

July presents really high temperatures, a dry climate, and a scorching sun through the daytime!

The average temperature is 28°C/82.4°F (maximum 35.1°C/95.2°F | minimum 23°C/73.4°F).
On the coldest nights, the temperature may drop to 21°C/69.8°F.
On the warmest days, the temperature may reach 38°C/100.4°F.
The sunshine lasts approximately 12 hours.
Humidity reaches 59%, while the mean speed of the wind is around 8.7 kph (5.4 mph).
The mean sea temperature is 24°C/75.2°F; hence, the waters are quite warm.

The hottest month of the year (along with July), August is the very peak of the summer season. Kos is always full of visitors throughout August, with available rooms being few and far between! In case you want to stop by Kos and its warm sea waters in August, it is advised to book your ferry tickets a few months in advance.

The average temperature is 29°C/84.2°F (maximum 34.9°C/94.8°F | minimum 24°C/75.2°F).
On the coldest nights, the temperature may drop to 21°C/69.8°F.
On the warmest days, the temperature may reach 38°C/100.4°F.
The sunshine lasts approximately 11 hours.
Humidity reaches 62%, while the mean speed of the wind is around 7.9 kph (4.9 mph).
The mean sea temperature is 26°C/78.8°F; hence, the waters are at their very warmest.

September is still a warm month, but temperatures stay far from all-time highs! Some visitors prefer September for a visit to Kos because of its more budget-friendly options and the less-populated environment.

The average temperature is 26°C/78.8°F (maximum 30.7°C/87.3°F | minimum 21°C/69.8°F).
On the coldest nights, the temperature may drop to 20°C/68°F.
On the warmest days, the temperature may reach 34°C/93.2°F.
The sunshine lasts approximately 9 hours.
Humidity reaches 65%, while the mean speed of the wind is around 7.2 kph (4.5 mph).
The mean sea temperature is 25°C/77°F; hence, the waters are still very warm.

October is the slow end of the medium-high season, though its waters and climate remain warm.

The average temperature is 22°C/71.6°F (maximum 26°C/78.8°F | minimum 18°C/64.4°F).
On the coldest nights, the temperature may drop to 16°C/60.8°F.
On the warmest days, the temperature may reach 30°C/86°F.
The sunshine lasts approximately 7 hours.
Humidity reaches 68%, while the mean speed of the wind is around 6.6 kph (4.1 mph).
The mean sea temperature is 23°C/73.4°F; hence, the waters are a little warm.

November in Kos is a return to a more humid, breezy environment, with medium temperatures and colder sea waters.

The average temperature is 17°C/62.6°F (maximum 21°C/69.8°F | minimum 14°C/57.2°F).
On the coldest nights, the temperature may drop to 7°C/44.6°F.
On the warmest days, the temperature may reach 28°C/82.4°F.
The sunshine lasts approximately 6 hours.
Humidity reaches 70%, while the mean speed of the wind is around 7.1 kph (4.4 mph).
The mean sea temperature is 20°C/68°F; hence, the waters are a little on the cold side.

December is rarely a tourist time for visitors to stop by Kos, given that the island has a limited number of operating hotels, cold temperatures, and some rainfalls.

The average temperature is 14°C/57.2°F (maximum 17°C/62.6°F | minimum 11°C/51.8°F).
On the coldest nights, the temperature may drop to 10°C/50°F.
On the warmest days, the temperature may reach 22°C/71.6°F.
The sunshine lasts approximately 4 hours.
Humidity reaches 70%, while the mean speed of the wind is around 8.4 kph (5.2 mph).
The mean sea temperature is about 18°C/64.4°F; hence, the waters remain cold.