A marginally operating air-conditioning system may fail in hot
weather, according to the ASE. Put a thermometer in your car’s vent
while the air conditioner is running and see how cool the air is
getting.
If it’s not cooling properly, you may try replacing cabin air filters
that clean the air entering the heating and air-conditioning system in
newer cars. Check your owner’s manual for location and how often they
should be replaced.
However, if your air-conditioning system is suffering from a bigger
problem — like a leak or loss of refrigerant — it’s likely time for a
mechanic.
