A/C works intermittently when outside temp is high

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. There is no real correlation to ambient temperature being high - other than a higher likelihood that the refrigerant will not cool properly when circulating back to the compressor through the condenser. Verify the condenser fans are blowing as needed with the system on. Of course it is important to ensure the system is fully charged, the compressor cycles properly, and the climate control system also works correctly. Seek guidance from a shop near you as needed -- https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.