The dry season in Honduras occurs in winter and lasts from December to May. It is definitely the best time for a trip to the country. In the mountainous areas, the day temperatures are high but the night air cools and becomes very comfortable. At altitudes above 3,000 meters it's even a little bit cool.
On the Caribbean coast and the subtropical islands, the dry season lasts from March to June. However, this just means that it rains less than usual.
Sometimes cold fronts arrive to Honduras from North America during the winter, and temperatures can drop to +10 °C in the capital Tegucigalpa and interior regions.
Even during the dry season, be prepared for some rain during the day. And in general, the humidity level is rather high throughout the year.