The only part of the “English” system of measurement that makes any sense is
Fahrenheit. The question “On a scale of 0-100, 0 being the coldest you have ever felt, 100 being the warmest, what would you estimate the temperature to be?” would yield an answer in +/- 5 degrees Fahrenheit for a majority of people in the US, and Europe, whether they understood the Fahrenheit scale or not.
Everyone I know would give an answer in Celsius/Centigrade. Today the temperature has been around 3 to 6 degrees. No one would say 40 degrees. 40 degrees is bloody hot around here.