Mauritius is far enough south of the equator to have significant seasonal variations in temperature.
May to September is their ‘winter’ period and although days are usually clear and sunny, temperatures tend to drop to the low to mid 20s celsius (70s Fahrenheit). To some visitors these temperatures are ideal (i.e. not too hot), but if you are hoping for very hot tropical weather you need to avoid at least June to August.
October through to April are generally warmer months, with temperatures reaching into the 30s (90s). However, from the middle of December through to early April it is cyclone season in the southern Indian Ocean.