Blue sky, bright sun, beautiful day...from my balcony, this is the first day of summer in Panama.
Yes, we are north of the equator, so technically we have the same "winter" months as North America and Europe. However, quite wisely, Panamanians simply chose the months with the best weather for a vacation, mid-December through end-February, and called that "summer" Rain is infrequent, humidity is lower, schools are closed, summer camps are operating, and school buses are not operating and adding to traffic. That makes life on the road a little easier.
In truth, "summer" goes on after the summer vacation is over. March, April, and beyond are not heavy rain months, the transition to the rainy season is slow. The heavy rain months are October and November in the Panama City metro area and they are not that uncomfortable. But the "summer" months are truly wonderful and I am always happy to see them arrive!