Mauritius has two kinds of climate. Below the 400-meter level on most of the windward (southeastern) side of the island and below 450 meters on the leeward side, a humid, subtropical climate prevails. Above these altitudes, the climate is more temperate, but there is no sharp break, and variations in exposure, altitude, and distance from the sea produce a wide range of patterns. The island has two seasons. The hot and wet summer lasts from November through April. February is the warmest month with temperatures averaging 27° C in the lowlands and 22° C on the plateau. Cyclone season runs from December through March, and the storms, which come from the northeast, have caused much destruction on the island over the years. For example, Cyclone Hollanda hit Mauritius February 10, 1994, leaving 1,400 persons homeless, and damaging 60 percent of the electrical system and 50 percent of the telephone network, as well as destroying between 20 and 30 percent of the sugarcane plantation. The overall cost of this cyclone was estimated at US$81 million.

Winter, lasting from May through October, is cool and dry, influenced by the steady southeasterly trade winds. July is the coolest month and has average temperatures of 22° C in the lowlands and 16° C in the plateau. Rainfall is abundant, ranging from 90 centimeters per year in the western lowlands to 500 centimeters in the tableland--an average of 200 centimeters per year overall. Nonetheless, the high rate of evaporation and uneven distribution necessitate irrigation. Humidity is frequently above 80 percent.

Mauritius has fertile soil that supports a variety of vegetation. All but 1 percent of the native hardwood forests that once covered most of the island have been cut down, threatening the survival of several bird species. Sugarcane is now the dominant crop, covering half the arable land, but other cash and food crops are grown as well. Coral reefs and marine life off the northwest coast have been hurt by pollution, mainly from large hotels. To prevent the destruction caused by rapid and poorly planned development and in response to foreign criticism for its lack of environmental protection, the government established the Ministry of the Environment in 1990. In July 1991, the legislature passed the Environmental Protection Act, which requires an environmental impact assessment for all new projects. The ministry has also established standards for existing industry, followed by inspections. Steps are being taken to induce the construction industry to shift from the use of coral sand (in the early 1990s the building trade used 600,000 tons of coral sand annually) to basaltic sand. Marine parks are being zoned to protect coral and marine life, and a sewerage master plan is being developed to prevent the discharge of untreated sewage into the ocean. Solid waste management is upgrading the handling of waste, and the principle of "the polluter must pay" is being introduced.

Data as of 1994