Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Hanoi to Salt Lake City as you normally would.
Expected rainfall in Hanoi is same as in Salt Lake City. You can expect this to be the case over the next 14 days.
Temperatures around the 35 °C's can be experienced in July. The weather in Salt Lake City is hotter than in Hanoi. Plan for potential changes in flight availability as peak weather approaches in this location.