I will visit Urumqi 28 May 17 - 8 June 17, how is the weather? What season is this period?

The temperature may range from 50 F to 75 F during that period of time. There will mainly have sunny and cloudy days. The climate would be cool and comfortable. And it belongs to the spring season.
In addition, you can see the flower blooming scenery at that time. April to July every year will be a nice time to appreciate the flowers. Have a nice trip!