what will be the temperature in may in liaoning province and what clothes to wear for men

It is warm for the whole month. But there is large temperature gap, with the lowest temp of around 10C and the highest one of 26C or a little higher. For some sunny afternoon, the temp may reach 30C. I suggest you take along both long-sleeved and short-sleeved shirts, shorts, light jeans and a light jacket. Besides, it may shower or have thunderstorm, so umbrella or other rainy gear can be prepared.

Thank you so much for the info. best regards