Diurnal temperature range values

I’m a bit perplexed by the variable station_diur_temp_rng_c. If my understanding is correct, this value should be the max station temperature minus the min station temperature (i.e., station_max_temp_c - station_min_temp_c). However, when I look at the values provided in the ‘column’ station_diur_temp_rng_c, the values don’t match up with my understanding. Perhaps my understanding of diurnal temperature is incorrect. Hoping someone could clarify.

@niks I believe diurnal temperature refers to “daytime” temperature only whereas the min/max temperature covers the entire 24 hour period of a day.