Africa
In March, spring begins in Northern Africa, and autumn in Southern Africa. In the Gulf of Guinea, both temperature and humidity increase, and therefore the first downpours can occur. On the coast of Northern Tanzania, the season of the long rains begins.
Where to go: Addis Ababa, Asmara, Cape Town, Conakry, Dakar, Cairo, Johannesburg, Marrakesh
Asia
In March, it begins to get very hot in the southern part of the Asian continent. It's still cold in the vast continental areas, and in those receiving cold winds from Siberia (Japan, Korea).
Where to go: Baghdad, Colombo, Doha (first half), Hong Kong (second half), Islamabad, Kathmandu, Kuwait (first half), Sana'a, Thimphu
North and Central America
In March it's still very cold in Alaska, Canada and Northern United States. In New York, March is typically a cold and unstable month, with possible snowfalls. In Central America it's hot and sunny, and only the north side of Panama and Costa Rica remains rainy.
Where to go: Guatemala City, Mexico City, Havana, Los Angeles, Miami, San José, San Salvador, Santo Domingo, Tegucigalpa
South America
In the Southern Hemisphere, in March it's still summer at tropical latitudes, therefore a hot, muggy and rainy weather predominates. Further south, autumn begins, and you can take advantage of it to find more pleasant temperatures than in the height of summer.
Where to go: Buenos Aires, Caracas, Lima, Montevideo, Santiago
Europe
March is the first spring month in Mediterranean countries, while it is still cold in Northern and Eastern Europe, where in general the temperature is still below freezing. It's still usually cold also in Central Europe. In Mediterranean countries, however, the weather is unstable, and waves of bad weather are possible. The highest temperatures are found in Southern Spain (see Seville, Córdoba), but in this month there's no shortage of rain. The days, however, in nordic countries are getting longer: around the spring equinox, ie March 21, the day lasts 12 hours throughout Europe (as in the rest of the world).
Oceania
In March, in the Southern Hemisphere it is still summer at tropical latitudes, with sultry heat, heavy rains and the passage of cyclones. In South Australia autumn begins, the temperatures are pleasant, but there is still some risk of heat waves. In New Zealand, it is the last month with pleasant temperatures and generally nice weather.
Where to go: Auckland, Wellington