usually, from what i know, the temp inside the bucket is higher than the temp outside the bucket...
bucket temp =75+
when your beer is fermenting, its temp is a bit higher than the ambient because it is a violent procedure..
and that makes heat...
(yeast eats sugar...)
you will learn to leave the lid on the bucket, if you take it off you won't ruin it
but it will then have to build the CO2 back up.. time, my not quite up to speed sibling, time...