Creek Freaks record weather the day of sampling, the day before sampling, and two days before sampling. This is because past and current weather will affect several water quality parameters. Rain and snowmelt increase the volume of water in the stream. Recent rain can carry additional chemicals into the stream as they wash off of roads and other surfaces. Extra rain can affect turbidity by stirring up more dirt and adding new dirt from the landscape into the stream. Rain and snowmelt can alter the water temperature, which in turn affects dissolved oxygen. If a weather event that occured in the last few days was unusual, the data results may also be unusual. Therefore it is important to record information about weather.