What do I need to be prepared for in July, in Kiev?

[Christie]

I will be traveling to the Ukraine for the first time this coming July. I am coming from Southern California in the United States, where the weather in July is fairly hot! Usually high 90's, sometimes pushing the 100's. My final destination will be Melitopal, for two weeks.
Also, can someone tell what the train ride is like from Kiev to Melitopal?
I am excited to come to the Ukraine and hope to hear from you soon! Thank you very much for your words and time.
Love, Christie (22, Student)