Naples, where it is

The climate of Naples, the capital of the Campania region, is Mediterranean, with mild, rainy winters and hot, sunny summers.
The daily average temperature ranges from about 9 °C (48 °F) in January and February to about 24 °C (75 °F) in July and August. Here are the average temperatures.
Naples - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)446812161818151285
Max (°C)131315182326293026221714
Min (°F)393943465461646459544641
Max (°F)555559647379848679726357

Rainfall is quite abundant, in fact, it amounts to about 1,000 millimeters (40 inches) per year; the wettest season is autumn, especially the months of October and November, followed by the winter months. Therefore, Naples is not always the "Sunshine City".
In summer, however, the rains are rare, and occur in the form of downpours or thunderstorms.
Here is the average precipitation.
Naples - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)105100857550352540801301601201005
Prec.(in)4.13.93.3321.411.63.15.16.34.739.6
Days1010109642468111191

The city is exposed to the south-west wind ("libeccio"), which brings mild and rainy days, but also to the north wind ("tramontana"), which brings a bit of cold, cloudy skies and some rain. On summer afternoons, the breeze blows from the sea, relieving the heat.

Winter, from December to February, is mild and rainy. The rains occur in periods of bad weather that last a few days, sometimes in the form of night thunderstorm, and are accompanied by the wind. There are also some pleasant and sunny days, with a bit of cold at night. In other cases, there can be some cold days brought by the north wind, during which some rain can fall at sea level, which becomes snow in the mountains, so it is possible to admire the snow-covered Mount Vesuvius. In the coldest nights, the temperature can drop below freezing (0 °C or 32 °F), usually not by much (2/3 degrees Celsius).

Spring, from March to May, is mild; the rains gradually become rarer, and fine weather more frequent. However, cold and windy days are still quite frequent in March, and sometimes also in April. At Easter, good weather is not always guaranteed. May is usually a good month, nice and sunny, although there may still be some cool and rainy days, especially in the first part of the month.

Summer, from June to August, is hot and sunny. Typically, the air is humid, but the sea breeze blows, tempering the heat. However, within the city, in the most densely populated neighbourhoods, the heat is felt more. Under the influence of the scirocco, the south wind from Africa, there can be hot days, with highs about 36/38 °C (97/100 °F). The rains are very rare, but we can not exclude some thunderstorms every so often.

Autumn, from September to November, is initially warm, and sometimes even hot, with many sunny days, especially in September and the first half of October. However, this season is also rainy, with possible waves of bad weather, accompanied by rains and thunderstorms, sometimes strong, especially by mid-October. In November, there can be the first quite cold days, especially in the second half of the month.

Naples

The amount of sunshine in Naples is very good in summer, when good weather prevails, it is good in May and September, while in the rest of the year, it's not always high, in fact, there are periods of good weather, but also others in which the sky remains cloudy for a few days in a row. Here are the average sunshine hours per day.
Naples - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours44568910108643

In June, the temperature of the sea is around 22 °C (72 °F), so it's a little cool to swim in, while it becomes warm enough from July to September, when it is equal to or higher than 25 °C (77 °F). Here are the average sea temperatures.
Naples - Sea temperature
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Temp (°C)151414151822252725221916
Temp (°F)595757596472778177726661

Best Time


The best times to visit Naples are from mid-April to mid-June and from September to early October. In both cases, you must put into account some rainy days, especially from mid-April to mid-May and from mid-September to early October. In summer, especially in July and August, there can be many sunny and not too hot days, but in other cases, the heat can be intense and sultry. However, those who can stand the heat can choose this period as well.
For a beach holiday in Naples and the neighbouring coasts (see Ischia, Capri, Sorrento, Amalfi) the best period is summer, in particular from June to mid-September, although, as we said, in June the sea is still a bit cool.