The 30-acre park now opens at 4.30am instead of 5am, and closes at 9pm.
BMA spokesperson Aekvarunyoo Amrapala said the move was in line with a policy to make public services more easily accessible and that opening hours of other public parks – including Lumpini, Chatuchak, Benjasiri, Saranrom, and Thonburirom – may be extended.
Nawamin Phirom Park is popular with nearby residents for strolling and exercise. It includes walking and running paths, and an about 2,000-metre jogging track.