I haven't heard about Mcair, which airport are they based at?
The weather in Denver is generally very good. Sunny and clear most of the time during the time frame you mentioned.
They do get some big thunderstorms in the summer and the wind can pick up but if youalways try to fly first thing in the morning then you will be fine. The air is smoother anyway.
The airpsace can be a little busy there since there are 3 airports in a small area, but good practise for you.
Good luck.
PB