Normal should be subjective normal, -40 is an extreme temp and over 40c is also extreme. I’m talking 5-25c where the lazy math works well enough.
So 20c is 68f proper conversion or 70f with lazy. 30, is 86f proper and 90f lazy. Basically for a normal day the temp is close enough that no one would notice.
is -40 not a normal temperature, at least compared with +30c?
Normal should be subjective normal, -40 is an extreme temp and over 40c is also extreme. I’m talking 5-25c where the lazy math works well enough.
So 20c is 68f proper conversion or 70f with lazy. 30, is 86f proper and 90f lazy. Basically for a normal day the temp is close enough that no one would notice.