A/C used to maintain temp but now it doesn't?

We have lived in our house for 8 years and the a/c has never had a problem maintaining 77 degrees during the summer in Florida. Two weeks ago, it started shotting up to 79 at about 5:00 and runs cnotinuously until about 8:00 then cools back down to 77. I had a maintenance check done last week and he said the freon was fine and he hosed off the outside coil, but that nothing else was wrong with the unit. He said he didn't think that cleaning the coil would impact the problem we are having. It has been rainy and overcast every day since that was done (Friday of last week - 6 days ago) but so far, the unit has maintained the 77 degre setting with problem. Is it possible it is only a coincidence because it has not been as hot the past week, or do you think that cleaning the outside coil solved the issue? What else could be the problem? The unit is only 8 years old.