Daily Mean Temperatures

This page displays the mean outside air temperature recorded each day by the automatic temperature sensor and is normally updated after each evening manual observation.

We define the mean temperature on any given day as the arithmetic average of the overnight minimum temperature recorded between midnight and 9:00 am and the maximum temperature recorded after 9:00 am. This differs from the conventional definition which uses the arithmetic average of the 24 hour minimum to 9:00 am and the maximum temperature recorded after 9:00 am. On most occasions both methods will produce the same result, however our method removes the rare cases when the 24 hour minimum occurs near 9:00 am the previous day.