When flying from Delhi to Boise, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
Delhi will have the same amount of rainfall in 1 compared to Boise over the next 5 days.
You can imagine temperatures to be in the 40 °C range in May. The weather in Boise is generally colder than Delhi's. As flight availability is subject to become more limited as peak season approaches it is ideal to book in a timely manner.