Mexico is mammoth, so the weather is as convoluted as a Mexican cocktail menu. End November until April on the coast is dry, hot and honeypots are buzzing. But in the northern mountainous regions, you’ll hit snow December, January and February.
The dry season is generally January, February and March (or November-April in Nicaragua, Panama and Honduras).
Feb-mid April is peak season for cruise ships, which frequent the big ports of Mexico, Honduras, Costa Rica and the Panama Canal. Getting a tailor made package will stop you getting a bruising from the cruising.
For whale watching in Baja, Mexico, during early February-end April the seas are, literally, singing. Calves join the chorus in February.
The rainy season can actually be quite beautiful, with greener landscapes, lower prices and fewer tourists. However, September and October bring seriously heavy rain in some parts of Costa Rica, with roads and rivers often merging into one. Many businesses shut down during this time anyway.
If you don’t do mornings, don’t do the rainy season. If you are an early riser, it is perfect in most Central American countries as the rain doesn’t kick in until the afternoon. So get up early, hit the hills or the heritage sites, siesta in the afternoon, and fiesta at night.
Although Costa Rica, Panama or Nicaragua hardly know what a hurricane is, Northern Central America has had its fair share of hurricanes, between June and November, with Honduras and Guatemala hit badly by Mitch in 1998. But note, they are not the norm.
Late November to April is also not the best time to visit Central America if you are on a budget as prices get hiked up during peak season.
If hiking in some of Central America’s highlands, temperatures are defined by altitude rather than season. In Honduras, for example, the average annual temperature is 32°C but it can dip to 20°C in mountain areas.
Costa Rica and Belize, in particular, pack out during US/European public and school vacations, in the honeypot areas. 4 July, Memorial Day at the end of May and Labor Day at the beginning of September are the biggies. Don't let them put you off though. Tailor made vacations are great for directing you off the beaten track during these times.