Is it a good time to play golf at the golf courses in Lijiang in the month of May?

Generally, it shall be ok to play golf at that time, but you may unexpectly meet rainy days sometimes. If you don't mind, I would highly recommend April to you, when the weather shall be very pleasant and the temperature would be comfortable, with the range of 10-24C from daytime to nighttime.

I am partly agree with Marsha, but May also is fine to enjoy yourself in Golf course.