Why are the daily temperature maxima and minima for different 24-hour periods?
Conventionally, maximum and minimum temperatures are recorded for 24-hour periods ending at 0900 GMT each day. Maximum temperatures tend to occur during mid-afternoon, so the relevant maximum for a given calendar day is the one recorded between 0900 on the day in question and 0900 on the following day. However, minimum temperatures generally occur around dawn, so the relevant minimum temperature for a given calendar day is the one recorded between 0900 on the previous day and 0900 on the day in question.
