Humidity changes the load
Your AC is not only dropping the temperature. It is also pulling moisture out of the air. When humidity is high, the system may run longer even when nothing is broken.
Homeowner Guide
Why your AC runs all day in Springfield humidity.
Long run times can happen during heavy heat and humidity, but they can also point to airflow restriction, dirty coil conditions, thermostat issues, weak performance, or a system that needs a closer look.
When long run time becomes a service call
If the system never catches up, rooms feel uneven, or the air is not getting cooler at the vents, start with the $95 Springfield Diagnostic. If it is mostly maintenance and coil condition, the Outdoor AC Tune-Up at starting at $80 in springfield may be the better first step.