"The Burning Season". You may not hear about this in the tourist travel blogs about Thailand but it is a big part of the life hear. Every year, January to April, March (the Dry Season) being the worst month, farmers and forest fires. Farmers clear and fertilise their land by burning their land. Also, sugar cane crops are burnt in preparation for harvesting.
For two or so months the climate is hot and dry, the air filled with smoke and dust, and the sky orange in colour and smokey in appearance. It is surreal. Most people, who can afford, buy an air purifier. Luckily, there are a number produced in Thailand that are fairly cheap. Walk outside with a mask.
This time of year is unpleasant, but I sometimes find it exhilarating. Like living inside a microwave. Enjoy.