Our thermostat is at 70 degrees... it's 99 outside and the room temp is 73... the air hasn't shut off all day. Is this normal?

Our thermostat is at 70 degrees...it's 99 outside and the room temp is 73...the air hasn't shut off all day. Is this normal?

Yes on extremely hot days your system is running at max capacity. You have a 26 degree TD (total differential between the outside temp and indoor temp). Your system is running just fine.

26 degree differential is fine. How about attic insulation? What is the R value. Good windows? I bet the AC works fine at night!

When significantly hot or cold weather strikes the setup is prone to show minimal changes. In your case it's not harmful or abnormal. This will probably keep happening if it's that hot out, so don't alarm yourself.