A 35 amp breaker should solve problem. We haven't discussed as whether this is a new problem you haven't had in previous summers. Could be related to the extreme heat wave we are currently having...
Agree, beginning to look like weak breaker. Check A/C unit outside, should give minimum breaker size. Given an 30 or 40 amp double breaker cost about $15, I'd replace it just on general principle. ...
That's really strange. Must be something happening at night that doesn't happen during day. Do you have a lawn sprinkler system that comes on during night that might be wetting the A/C disconnect...