"Normal" temperature is indicated by the needle staying within the "normal" range which is printed on the gauge. Ford doesn't put numbers on the gauge so people won't freak out when the needle is pushing past the normal boiling point on a hot day. FWIW, some days my car's needle stays in the middle and some days it's a little past or a little below and it doesn't matter whether it's day or night or what the air temperature is. I don't think the gauge is all that accurate but it looks better than an idiot light.
Karl
