Interpret the temperature graph correctly

Hello, I have two sensors installed inside a concrete pillar to record its internal temperature; the graph below is the result of the registration for 14 days (336 hrs), but I do not know because every 24 hours the data take a sharp jump (see graph) at 21:00 exactly and then the same for the next day.

What can this be?, Some comment?

hi @ricardo_ramos.l we need to know more about your setup. can you provide the following.

  • which device are you using.
  • which sensor is connected.
  • power supply used for powering.
  • share the entire code used
  • screenshoot of the graph on your dashboard
  • downloaded CSV file.

this is something new what we have encountered so not sure what is causing this bug. Need to do some test so need the above all information.