I read somewhere that evaporation increases with water temperature. But what if the water is cold, but the air even colder. Last night we seem to have lost a quarter of an inch. The water temperature is 55 and the temperature got down to 36 overnight. Would you expect a lot of evaporation in those conditions? I tried the bucket test and I 'think' the bucket lost the same amount of water. I'm just questioning the validity of the test because the evaporation seems somewhat high to me.