Map from Google - Kalymnos

In Kalymnos, island of the eastern Aegean Sea, and belonging to the Dodecanese group, a short distance from the Turkish coast, the climate is Mediterranean, with mild and rainy winters, and hot and sunny summers. The average temperature of February is 9.5 °C (49 °F), that of July is 25.5 °C (78 °F).
Here are the average temperatures.
Average temperatures - Kalymnos
KalymnosJanFebMarAprMayJunJulAugSepOctNovDec
KalymnosJFMAMJJASOND
Min (°C)8710121519212120161210
Max (°C)131215182227302927221713
Min (°F)464550545966707068615450
Max (°F)555459647281868481726355

Precipitation amounts to 730 millimetres (28.5 inches) per year, and is concentrated between October and March; it often occurs in the form of thunderstorm, and sometimes can be abundant. In summer it almost never rains. Due to the length of the dry period, the landscape is arid, even in the inland hills, whose highest point is at about 600 metres (2,000 feet) above sea level.
Here is the average precipitation.
Average precipitation - Kalymnos
KalymnosJanFebMarAprMayJunJulAugSepOctNovDecYear
KalymnosJFMAMJJASONDY
Prec. (mm)170115753520825156090135732
Prec. (in)6.74.531.40.80.30.10.20.62.43.55.328.8
Days12108642012581270

Winter, from December to mid-March, is mild enough: daytime temperatures hover about 12/14 °C (54/57 °F). The rains are frequent, but there are also sunny days. Sometimes it can be a bit cold, with highs below 10 °C (50 °F). The wind can increase the feeling of cold. Sometimes you can even see a bit of snow, usually however with no accumulation, at least in the plains.

Spring, from mid-March to May, is mild, and over the weeks becomes progressively warmer, with more sunshine and less rain.

Summer, from June to mid-September, is hot and sunny. The Meltemi, the north-west wind, blows from mid-May, cooling the air, but with lower intensity than in the central islands of the Aegean Sea. In addition, sometimes there are some periods of intense heat, with highs around 35 °C (95 °F).

Autumn, from mid-September to November, is often sunny and pleasantly warm at the beginning, and then gradually becomes milder, and also wetter.

The amount of sunshine in Kalymnos is great in summer, when clear skies prevail, it's very good in late spring, while in autumn and winter it is only decent, because sunny periods alternate with others characterized by clouds and rain.

Pothia, view

The sea is warm enough for swimming from July to September, and reaches 24 °C (75 °F) in August.
Here are the average sea temperatures.
Sea temperature - Kalymnos
KalymnosJanFebMarAprMayJunJulAugSepOctNovDec
KalymnosJFMAMJJASOND
Sea (°C)161616161921232423211917
Sea (°F)616161616670737573706663

When to go

The best time to go to Kalymnos for beach life runs from June to mid-September. In early June it can still be a little cool in the evening: for safety you can bring a sweatshirt.
In May, not only the sea is still a bit cold, but the air can be cool even for sunbathing, at least on certain days.
For hiking, the best time is spring, especially the month of May, since in summer it can be hot. You can also choose autumn, especially October, whereas November is cooler and rainfall is more frequent.

Back to the Dodecanese.