Why is the temperature rising in my backdoor at 01:48 am ?

hi, recently bought an Oregon wmr100n and ive place the humidity/temp sensor out in the stevenson box in the garden. the temp was going down until about an hour ago where it went up by 0.6C, when it should be going down, any ideas why ? thanks

Minor fluctuations in temperature are not uncommon, especially later at night.  Minor increases in wind can stir up the air and warmer pockets of air can pass by as well.