Even in a desert, people still use umbrellas for protection from the rain:

https://lasvegassun.com/news/2016/jan/19/fast-moving-storm-b...

And the rain still causes problems, even (or maybe especially in) a desert:

https://nypost.com/2022/07/29/las-vegas-braces-for-more-rain...

1 person using an umbrella, 4 are not. I'm starting to doubt if you're even human given that normal people don't go throughout their entire lives always carrying an umbrella wherever they go, even when it might rain.