Map from Google - Samos

In Samos, an island of the Eastern Aegean Sea, 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 January and February is 10 °C (50 °F), that of July and August is 27 °C (81 °F).
Here are the average temperatures.
Average temperatures - Samos
SamosJanFebMarAprMayJunJulAugSepOctNovDec
SamosJFMAMJJASOND
Min (°C)77811141922221915119
Max (°C)131316202530333229231815
Min (°F)454546525766727266595248
Max (°F)555561687786919084736459

The rains amount to 630 millimetres (25 inches) per year, and are concentrated from November to March; they often occur in the form of thunderstorm, and sometimes may be abundant. In summer, basically it never rains.
Here is the average precipitation.
Average precipitation - Samos
SamosJanFebMarAprMayJunJulAugSepOctNovDecYear
SamosJFMAMJJASONDY
Prec. (mm)95909045202111735120120630
Prec. (in)3.73.53.51.80.80.1000.71.44.74.724.8
Days12109741001591472

Winter, from December to mid-March, is mild: daytime temperatures hover around 13/15 °C (55/59 °F). The rains are quite frequent, but there are also sunny days. Sometimes it can be a bit cold: lows can drop to 3/5 °C (37/41 °F), and highs to 7/10 °C (45/50 °F); in addition, the wind can increase the feeling of cold. In the plains, substantially it never snows (sometimes you can see the snow falling but it does not accumulate on the ground), while on the highlands of the interior, whose highest peak is Mount Kerkis, 1,433 metres (4,701 feet) high, sometimes it can snow.

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, humid and sunny. The Meltemi, the wind from the north-west typical of the Greek summer, blows from the middle of May, cooling the air, but with less intensity than in the islands of the Central Aegean Sea. Periods of intense heat, with highs about 35 °C (95 °F), are quite frequent, and sometimes the temperature can touch 38/40 °C (100/104 °F), but fortunately sea breezes blow in the afternoon.

Autumn, from mid-September to November, is at first pleasantly warm and often sunny, while it gradually becomes milder, and also wetter.

Vathy

The amount of sunshine at Samos is excellent in summer, when clear skies prevail, and very good in spring, while in autumn and winter, sunny periods alternate with others characterized by clouds and rain.
Sunshine - Samos
SamosJanFebMarAprMayJunJulAugSepOctNovDec
SamosJFMAMJJASOND
Sun (hours)56791113141311865

The temperature of the sea is never very high, since it reaches a maximum of 23 °C (73 °F) from July to September; in June it is still a bit cool, about 21 °C (70 °F).
Here are the average sea temperatures.
Sea temperature - Samos
SamosJanFebMarAprMayJunJulAugSepOctNovDec
SamosJFMAMJJASOND
Sea (°C)161615161821232323211817
Sea (°F)616159616470737373706463

When to go

The best time to go to Samos for beach life runs from June to mid-September. In early June, it can be a little cool in the evening: for security you can bring a sweatshirt.
In May, not only the sea is still a bit cold, but also the air can be cool for sunbathing, at least on certain days.
To visit the ruins of ancient Greece, the best time is spring, in April and May, since in summer it can be hot. You can also choose autumn, at least until October, because later the rains increase.

Back to the North Aegean Islands.