Tough to say and I'm not an expert, but it looks dry. Test the ground down about 2" (~5cm) and see if the ground is dry or damp.

What type of soil do you have? Did you say you still eater even if it rains? Mangos are prone to root rot if watered too much. They like it dry...

Check the tips to see if there's any sign of insects eating into them. There are pests that burrow into the tips of branches and cause that type of die back.

Is July your summer? What sort of temperatures were there before the rains came? A lot of water in summer/wet season isn't a problem. During our wet season some Mangos stand in water for 2 to 3 months without any problems. A long hot dry season could affect newly growing tips.

Too dry. Even the weeds are struggling. Much more water AND mulch.

Were your fruits clean? Or, did they have black spots or black covering them?

Your pics are backlit and not helpful. Take pics pointing at a dark object like another dark tree, shaded house wall or down at the grass, with flash if possible. Also you did not say whixh cultivar your mango is.

My mangos got a LOT of water this year and its one case where sandy soil is a plus and they suffered no ill effects. That will only be a problem if you have bad drainage.

Wet weather and lawn sprinklers can bring on anthracnose

If you water at night to get by water restrictions thats a BAD thing for mango and good for fungus. If this is the case 2x per week during authorized morning hours IN THE SUMMER will keep everything happy.

Evening watering is OK if you do NOT get the foliage wet.

Anyway, you can spray with copper fungicide to prevent fungus spread and spray again when they flush next.