The dry season
The dry season in Belize runs from December to May, which also coincides with the high season in terms of travelers. During these months, temperatures tend to be a little cooler and conditions are generally drier, with less rainfall and lower humidity. This doesn't necessarily mean that the weather is always fine, as northerly winds can lead to cloud cover. The coolest months of the year are generally December, January and February, with slightly warmer conditions in the southern parts of the country. These are also the months with the coolest nights. A light jacket may be useful. March, April and May tend to be a little warmer and drier, with daytime temperatures sometimes reaching 32°C. May is generally a little wetter as the rainy season approaches. Even during the coldest periods of the year, the waters off the country's east coast are warm and inviting, while the rainforest is less oppressive. Take advantage of these conditions to make the most of your visit.
The rainy season
The rainy season in Belize runs from June to November, bringing warmer temperatures and generally wetter conditions. Thunderstorms tend to form in the afternoon, with heavy rainfall lasting an hour or two before ending in the evening. This means that even on rainy days, during the wettest time of the year, the sun manages to shine for a while. Generally speaking, September and October are the wettest months of the year, with southern Belize being the wettest region, with rainfall decreasing slightly as you travel north. Average temperatures during the rainy season will hover around 31°C, which, along with high humidity levels, can sometimes make conditions unpleasant especially in the dense jungle further inland, while on the coast, ocean breezes help to mitigate the hotter conditions. Unsurprisingly, the rainy season concedes the low season for travel in Belize, which means fewer people at most attractions. This can also mean better prices on airfare, hotels and amenities, but keep in mind that some popular tourist destinations may be closed. For example, heavy rains can make it dangerous to visit Barton Creek Cave or Actun Tunichil Muknal, so these places could be completely closed to visitors.
Hurricane season
Like any country bordering the Caribbean, Belize is at risk of falling into the path of a hurricane. Generally speaking, the Atlantic hurricane season runs from June to mid-November, with the risk of dangerous, destructive and potentially deadly storms during this period. In Belize, the highest probability of such storms occurs between August and October, with occasional exceptional cases occurring from time to time. Although destructive hurricanes have struck Belize in the past, chances are you'll be completely safe throughout your trip. This is especially true if you plan to stay further inland, as coastal areas, as well as Belize's reefs and cays, are usually the hardest hit by the storm. Still, it never hurts to be as prepared as possible when visiting a destination where a hurricane remains a possibility.