What is considered warm freshwater?
What is considered warm freshwater? Classification systems based on water temperature vary by management agency and region (1), but in general rivers and streams with an average daily summer water temperature greater than 20°C (68°F) are considered to be warmwater (2).
Is 20c too cold to swim?
20C: You might like a wetsuit for longer swims but not necessary. 18C: Time for a wetsuit unless your swim time is quite short.