How hot does my attic get?

We’re going to be having some roof work done in the next month or so, and one of the tasks is to install a ridge vent along the main peak of the house. I have a pretty sizeable attic, but the only ventilation is through two relatively small gable vents at each end. The roofing contractor suggested adding the ridge vent, and said it could even help with keeping the whole house cooler. Since our portable air conditioner seems to barely be able to cool our bedroom, I thought it certainly couldn’t hurt.

I decided to get some temperature readings in the attic before and after and see how they compare. I have an indoor/outdoor thermometer with a wired exterior sensor, so I stuck that up into the attic and left the display unit in the closet. I closed the closet doors and turned the A/C on in the bedroom.

The outside temperature today was about 85°F with a considerable amount of sun. The max temperature in the attic reached 119.1°F. I guessed it would get to 120°F. Not bad! What really surprised me was the fact that the bedroom closet with the doors closed and the A/C running in he bedroom got to 93.7°F! That’s a lot of heat buildup when the room on the other side of leaky bi-fold closet doors was about 72°F!

I have high hopes for the ridge vent releasing a lot of that heat, especially if it will make my A/C work a bit better. I’m going to monitor the attic temp for a few more days to get some more data, then get some data afterwards as well. Stay tuned.

Updates:
Sunday: 113.2°F/93.7°F Outside Max: 85°F
Monday: 95.5°F/71.2°F Outside Max: 70°F
Tuesday: 106.5°F/70.2°F Outside Max: 75°F