New AWS set record low 2010
November –18.0 °C Llysdinam (Powys) 28 November 2010
Same as inside your freezer.
Estimated Class 5, image not clear enough to measure and might be marginal Class 4. Poor exposure. Microclimate.
UHI, local site, distance none.
This site is extraordinarily poor for an AWS but with site management problems. Notes state repeated no staff available for instrument reading, then the times switch to very abnormal, then 26/10/2010 it switches to hourly automatic. One month later an all time low for Wales.
The site is unstable, Google history shows major changes close to the screen.
The reason for persisting with this station: claims to have start data of 01/01/1882, although it is clear there have been several site changes within the present database.
Presumably there was some kind of temperature inversion, lying snow where the poor exposure led to a low yet better exposed sites did not (would have been lower).