Khao Yai is located 400 m and higher above sea level, making it cooler and more pleasant than the hot, humid lowlands in Central Thailand. The dry season that lasts from November to February, when most people tend to  visit, has temperatures that can fall as low as 4-6 degrees Celsius.

The cool weather and clear skies make this the favourite season for hiking and birdwatching. But you are recommended to take some warm clothing with you when you go. The hot season in Khao Yai is between March and April, followed by the May to October rainy season. The park is open during the rainy season, but travelling on foot is rather difficult, and you should take heavy raingear and leech medicine.