Best time to go to Le Morne
The best time to visit Mauritius is between June and October, when the mercury hovers around 24˚C and the weather's at its driest. The country's cyclone season usually starts in December and ends around March, so we'd recommend avoiding these months. For the most part, cyclone's near Mauritius stay out at sea and don't affect the island. However, it's not uncommon for them to hit land, bringing strong winds and rain showers with them.
Just a heads-up, some of the beaches in Mauritius can be affected by increased amounts of seaweed from time to time. Don't worry, though, if you're staying in a hotel by a beach that's affected by the seaweed, the hotel staff will work to clear it as quickly as possible.