I am going to Zhengzhou, Henan Province at the end of April. I would like to know what the climate will be like there? Cold or hot?

Zhengzhou should be neither cold nor hot around May Day. Zhengzhou gets hot around June. Upstairs, wearing short sleeves at the end of April is really healthy... I guess it's about the same as bringing a T-shirt, a jacket, or at least long sleeves. Because Zhengzhou is not the south after all, even if it is hotter during the day, it is still quite cool in the morning and evening.

However, the weather is not normal now, so you should check the weather forecast before coming.