Aircon cold enough only when weather is cold?
A non acid foaming coil cleaner on the outside condensing unit will work much better than vacuuming. If you can see light through the fins this may not be needed and a service call to fill the system may be needed. If low on freon the tech may be able to find the leak. Many times on older units the service port caps get loose and need some sealer on the threads after a recharge.