You need to find out from a reliable source just before you start your hike. That means talking to someone who has visually confirmed the water sources at just about the same time you are starting your hike.
Do you know what the average temperatures and highest recorded temperatures are for the areas you are hiking?
This turning out to be one hot year in the deserts. Have you hiked in those temperatures before?
Do you know how much water you need for those temperatures, based on personal experience?
In temperatures around 100*F I need a minimum of 2 gallons of water per day, and I live in one of the hottest deserts in the US, so I am acclimated to desert hiking. Where I live hikers die every year after only 8-10 hours of hiking when they do not have enough water. If you get into trouble, can you be rescued in that window of time?
This is a very serious hike in July, and should only be undertaken by experienced desert hikers with ACCURATE water information, IMO.
This is a pretty dry and hot year in most of the southwest deserts.
Here is the temperature where I live on May 31st at 4:29 PM.