Pretty interesting I check my oil pretty often. When we were really cold I thought I was losing oil because I keep it about in the middle and in 30-40f it was reading at the min. Now today it's 74f here and I'm back in the middle. I always check it after not running 12+ hours.

 

reason most manuals say to check the stick a few minutes after turning OFF the warm engine...

so temperature of oil will be near the same..

like any fluid.. it changes with temperature...

like mercury in a thermometer ,,, later colored alcohol

also remember motor oil.. 5w20, 10w30.. will also be different..

remember a "Little" LOW on oil is better then "OVER" full..... fyi.