Réunion's climate experiences only two distinct seasons: the hot, rainy summer from December to April and the cool, dry winter from late April to November.
The peak tourist season is during the French school holidays from July to early September. From October through to the New Year holidays is also busy, but after this everything eases down during cyclone-prone February and March.
Temperatures on the coast average 22°C in winter and 27°C in summer. In the mountains, they drop to 11°C and 18°C respectively.
The drier winter months are the most favourable for hiking, as some of the trails are simply impassable when it's wet. The east coast is considerably wetter than the west.
The whale-watching season runs from June to October.