High season in most areas lasts from December to April, when temperatures are generally more bearable. The hotter, wetter season is from May to November - rain ranges from late-afternoon showers to days of prolonged downpours, with a risk of hurricanes in coastal areas between August and October.
South of the tropic of Cancer (which cuts across Mexico north of Tampico) it's hot and humid, particularly along the coastal plains and the Yucatán Peninsula. Inland, at higher elevations, it's much drier and temperate. Mountain areas can get very cold in winter, and often have snow.
Mexico has a reputation for constant festive fun: just about every month brings a major national holiday or fiesta, and every other day is a local saint's day celebration. The most important public holidays are:
January 1: New Year's Day
February 5: Constitution Day
February 24: Day of the Flag
Late February / early March: Carnaval (Carnival) - the big bash before the 40-day penance of Lent
March 21: Anniversary of Benito Juárez's birth
March/April: Good Friday and Easter Sunday
May 1: Labour Day
May 5: Celebration of the 1862 victory over the French
September 16: Independence Day - celebrating the start of the war for independence from Spain
October 12: Día de la Raza - celebrating Columbus' 'discovery' of the New World
November 2: Día de los Muertos ('Day of the Dead'), held the day after All Saints'. The souls of loved ones are believed to return to earth on this day, and for weeks beforehand markets are awash with candy skulls and papier-mâché skeletons that form part of welcoming shrines (along with fruit and other offerings) for the spirits
November 20: Día de la Revolución - anniversary of the 1910 revolution
December 12: Day of Our Lady of Guadalupe, celebrating the country's major religious icon
December 25: Christmas Day
BY AIR: The main carriers include:
DOMESTIC FLIGHTS: The main airlines are Aeromar, Viva Aerobus, Volaris, Aerotucan Airlines and Interjet.
BY CAR: Car hire is available in most Mexican cities, but it can be expensive. If you do rent a car, Jeep-styles are best as they cope better with the jagged speed bumps. See our car rental recommendations.
BY BUS: Mexico is blessed with a superb bus network - but you won’t be seeing any of the smaller villages along the way, so bear this in mind when you plan your journey. Reservations and bus schedules for services across Mexico can be found at miescape.
BY BOAT: ferries connect Baja California with a number of ports on mainland Mexico e.g. Santa Rosalia to Guayamas, and La Paz to Mazatlan and Topolobampo. There are also smaller boats to islands off the Caribbean coast e.g. from Chetumal to Xcalak, and to neighbouring countries e.g. Xcalak to Belize.
Plan ahead for immunisations (give yourself 6 weeks), as some injections shouldn't be taken together; diptheria, hepatitis A, hepatitis B, typhoid and polio are normally recommended. You may also need to take anti-malarials if visiting certain areas - consult your doctor for advice.
Most people travel happily around Mexico unafflicted by anything other than diarrhoea and an upset stomach from eating too many street tacos. But if you do get ill, consult a doctor and get a second opinion if you're worried. The local consulate or tourist office of the town you're in can usually recommend someone reliable (who will expect to be paid in cash). Most antibiotics can be bought over the counter at a chemist (make a note of any medication you're allergic to), and every Mexican town has a hospital and a Red Cross (Cruz Roja) emergency service.
Visitors from the UK should check Travel Health Advice for more information.