Water temperature affects physical and ecological processes, but a sensor reports conditions at one location and depth. Sun, shade, current, inflows, wind, season, and stratification can make other parts of a lake or river substantially warmer or colder.
The timestamp matters. Afternoon shoreline water can differ from an overnight main-channel observation. So can surface water and deeper layers.
Temperature alone cannot establish swimming safety, harmful-algal-bloom status, pathogen risk, drinking-water safety, or fish stress across an entire waterbody. Those questions require suitable measurements and official advisories.
LakeRiverNow shows the station relationship and never fills a missing temperature with nearby weather or a modeled estimate. Unit switching between Celsius and Fahrenheit uses a tested conversion and does not change the stored source value.