A good rule of thumb is if you are comfortable then your baby is probably comfortable. If you dress your baby very warmly at night then you will want the temperature to be a little cooler however, if your baby sleeps in only a diaper then it should be warmer.
I have three kids and I found that the ideal temperature was 68 degrees. The room was not too cold during the winter months and not too hot during the hot days of summer.
Babies up to 6 months old can be kept comfortable at a room temperature between 70-73 degrees F
without having the worry of adding heavy blankets which could cause accidental suffocation. Cover the
infant's head with a baby hat for added warmth at night.
A good thing to remember is that babies aren't much different than adults when it comes to the temperature of their environment, and whatever feels comfortable to an adult should be fine for a baby. The keyword here is comfortable, not tolerable.
Well if you search for the temp on the internet it will state the safe temp should be btwn 61 and 68 degrees. I always check my son's hands they say if they are warm/hot then it's too warm in the room.