Burma (Myanmar) has a tropical monsoon climate. Broadly speaking, there are three distinct seasons in Burma — hot and dry from late February to late May, the rainy season from late May through to October, and the cool and dry season from November through February.
When it comes to breaking up the country by climate, Rakhine State, the Delta (including Yangon) and South Burma tend to have the most rain and humidity, and they stay the warmest during the cool season.
The dry zone includes Bagan and nearby areas in central Burma, and suffers the most during the hot season with high temperatures and little shade, but the zone cools off during the rainy season.
The upper-central, north and east regions are generally at a higher altitude, and tend to be cooler (even very cold) at night and have the most forgiving climate in terms of hot temperatures and rainfall.
Rakhine State, the Delta and South Burma
These regions have high temperatures and humidity from February to May. Choose your clothes wisely to pair with the heat and the conservative nature of this religious area (wearing shorts and bare shoulders usually bring frowns from the locals). June to October carry over the high humidity and bring intense rains that can often close roads and cause delays when it comes to transportation. Generally you want to avoid this particular area during the monsoon, which tends to be more intense than most elsewhere in Southeast Asia. Another consideration during this time should be mosquitos and the malaria and dengue fever that comes with them. November to February is gorgeous, bringing warm weather and reliable sunshine.
The dry zone and lower-central Burma
The dry zone and lower-central Burma tend to be more arid and dry (hence the name), with extreme temperatures from February to May. Just as above, make sure to choose your clothes wisely as locals are conservative here too and the rays are intense. June to October bring in a welcome relief to the heat with moderate showers. November to February bring the best weather for this area, and can even get to a chilly temperature during the nights.
Upper-central, north and east
This part of Burma tends to have more of a fluctuation in temperature throughout the day. During February to May, daytime can bring very high temperatures and intense sun. The evenings cool off more than south Burma but people tend to look for higher altitude areas such as Kalaw and Pyin Oo Lwin. June to October bring moderate rains which are more welcomed than they are in the south; the temperature lowers and the rain is less frequent and intense. November to February bring cool to very cold temperatures for those in higher altitude areas. In areas such as Kachin, and the lower Himalayan areas, you will even need gloves to go with your jacket and pants.
When is the best time to visit Burma?
November to February are the months that have the easiest and most comfortable weather to travel across all of Burma. Clear skies and lower temperatures are fairly steady throughout the whole country, which is usually lush green from the just-passed monsoon. If travelling during February to May, be prepared for the heat, no matter where you are, and expect to be more comfortable in upper-central, north and west Burma more so than other areas. During the rains of June through October, avoid travelling through the south, as the islands tend to shut down their transportation, and join the people heading anywhere north of Yangon.