Big temperature swings

[TimC]

Hi, it’s been a while since I’ve smoked a butt.  I did so yesterday and noticed that my temperature would swing 50 degrees or more.  Does this seem normal?  It seemed to work its way back up to 250 degrees.  In the graph you can see that I started turning down the temperature to lower it but it still kept working it’s way up to 250 degrees.  Thoughts?

 

[Hokie_CO]

Cool graph. I would say those temperature variations are normal for on-off control with a mechanical thermostat. The thermostat has a dead band that keeps it from cycling on and off too frequently and wearing out the contacts. It's the average temperature that matters for cooking the meat.