Strong chances of rain next few days in Nice and surrounding areas

Carry an umbrella and continue as planned? It’s not likely to be actually raining the whole of the time.

Have you checked the train schedules for a day trip outside of the rain zone? It would be a 3 hour train ride but I believe there is a direct train to Avignon that leaves early morning. The https://www.palais-des-papes.com/en is outstanding.

Day trip to Italy??

Good time to hit the Museums, Castles, etc. Don't let the rain stop you. Sometimes a forecast of rain does not happen until evening. Go for it!

Thu and Fri aren't looking that bad, so perhaps keep the museums for Saturday. If it's just showers, you can keep going with whatever you had planned.

You can try booking a tour to the countryside with a driver, which will minimize your time out of doors. There are village routes and even a Bellet wine region tour. There are classes you can take, including cooking classes. And since it is a city, there are live music venues and the arts, concerts etc sometimes in English. If you look at theaters, look for VO on the marquee/listing for english).

If you are not into museums, but something close is the Villa Ephrussi (although the grounds are the real feature) or Villa Kerylos. There are also similar buildings and even older ones, thoughout the area. The Musee Massena is a museum, but focuses on local history and is housed in a beautiful villa. The Musee Lascaris is in an even older building. These can be viewed on the same ticket in a 24 hour period, along with many others.

More ideas here: https://www.explorenicecotedazur.com/en/explore/ or

The weather report with the 8 pm news showed Thursday is rainy in Nice but not Friday, just cloudy.