Nice is famous for its climate. Some inhabitants sometimes brag so much about it that you might think that they have a part in the nice weather.
We actually owe this climate to the mountains at the Italian border (the Mercantour mountains), North of the city and which top 3200m. They protect us from the cold winds from the North and create a foehn effect on the sea shore. Besides there is also the thermical effect of the Sea which heats the air in winter and cools it down in summer.
In Nice we also have the Mistral, this chilly North wind blowing sometimes in the Rhone valley, Marseille and Toulon. But here it blows from the West and is not as strong, and not as cold. In case of Mistral, you'll see the the airliners turn in final at low height above the Angels bay to line up and land. An impressive view.
In Nice, the bad wind is the Eastern wind. It brings bad weather.
In summer, now and then blows the Sirocco, a hot South wind bringing with him the sand of the Sahara. Don't be surprised if your car, in the morning, is covered with a thin layer of sand.
A typical year
Summer is hot, no surprise, but usually not too hot. Many thunderstorms in the mountains and also on the sea shore. A few years ago these storms used to begin after the 15th of August but lately (green house effect?) we've had them all summer long.
September and October are usually very nice, with still warm temperatures and very little rain.
From the end of October to mid december the weather is more uncertain. We can have rain or grey skies during weeks.
From the end of december to the end of February, it's usually a bright and clear sky, with no sea mist. But there are also sometimes a few days in a row with bad weather. Question of luck.
March and the beginning of April : rainy and cloudy weather possible during several days, even weeks in a row.
May and June : the summer is (almost) back.
Of course, Mother Nature doesn't always respect this scheme.
If you want to know the weather in Nice today or the forecast for the next few days use this link.
To have reliable statistics on the climate in Nice use this Meteo France page. Do not be surprised if there is less sun in winter. Days are simply shorter. But we say it again : it is in winter that you'll find the brightest days. That's also in winter that the differences between the weather in Nice and the weather in the Noorthern parts of France and Europes are the largest. As you guessed, it's our favorite season on the Riviera.
If you don't know the Mediterranean Sea, you'll discover that there are almost no tides here. The difference between highest and lowest tides is less than 5 to 10 cm, unnoticeable.