Be mindful that when properly sizing your air conditioning system for your home there are more factors involved than just the square footage of your home.
Your A/C is sized for an outdoor temperature of 88 degrees in the summer. So when it is above 88 degrees your air conditioner is now too small, undersized. You may find that it will run longer to cool your home. If it is older, dirty, and 100 degrees outside than it could be a recipe for disaster.
Cool off your A/C today with a watering from your hose. They get hot too, & it will help the system work better.