During late February 2018, very cold air arrived from the east (earning the name ‘the Beast from the East’). On the 1st of March, a low pressure system tried to push up from the south, strengthening the easterly winds while its fronts brought significant snow. Harpford is relatively sheltered from easterly winds however some exposed areas had blizzard conditions and large drifts.
Overnight a milder layer of air was drawn in at about 1,500m altitude, above the sub-zero air below, and the result was freezing rain to an extent that is unusual here. Many surfaces were coated in 1cm+ of ice. In some exposed areas the extra weight combined with strong winds led to some tree damage.
In the snowfall on the 1st, the temperature did not rise above -3.0°C until 5pm, although it had reached -0.6°C by midnight. Again on the 2nd, the daytime maxima was 0.1°C, but it rose to 3.9°C just before midnight.
The wind prevented any exceptionally low minima at this location (compared to months such as December 2010), but increased wind chill. The minima of -5.3°C on the 28th February and -5.2°C on the 1st March are still the lowest I have recorded with windy conditions. With no valley inversion, higher ground had lower temperatures (around -7°C to -8°C on the higher hills in Devon, and -10°C on the tops of Dartmoor).
This Met Office page gives a national context and data https://www.metoffice.gov.uk/climate/uk/interesting/february2018-snow