Besides these pages, you should also read the Tourist office agenda. Well designed, it enables you to select the kind of event you're interested in and the dates.
The drawback is that their aim is more to promote than to inform and give opinions.
C'est pas classique
A free festival of classical music (in november).
Carnival
In February.
Paris - Nice
The famous cycling race, in March.
Jazz festival
The oldest jazz festival in France. (In July). Cancelled in 2020 after the sanitary crisis.
Next festival in 2021, 12-17th of July.
Prom party
Free concerts and fireworks on the Promenade des Anglais. July and August.
Heritage days
Free entrance and exceptionnal openings of monuments (in september)
