why does a/c not work when temp is 90 degrees plus

What is your question?

2006 dodge Durango 5.7 hemi on hot days the a/c works when first started but when shut off for a few minutes then restarted a/c does not work a/c works fine on lower 80's and cooler outside

What makes this problem better or worse?

its worse when engine has been running a while

How long has your 2006 Dodge Durango had this problem?

since last summer