The graphic shows live weather data at Littlehempston, Devon, UK.
Historical data over a year
The upper chart shows soil temperatures in the greenhouse over the year April 2020-April 2021. Typically they rise to 21-22 deg C in late summer, and drop to 9-10 deg C in late winter. The winter of 2020/1 was quite cold and the soil temperature in fact went lower to around 8 deg C.
The lower chart shows the soil moisture levels inthe glasshouse. This goes through cycles of drying and recharge via the drip irrigation system.
The upper chart shows greenhouse average air temperatures over a year. The difference between inside and outside air temps over the year is about 5 degrees C (slightly more in summer, slightly less in winter). This equates roughty to the climate of south west Portugal.
Weather data for 3 years to March 2021.
The aim is for the greenhouse to be frost free but as you might see, this is not quite the case. Temps of -0.5 and -0.6 deg C in Jan/Feb 2019 in fact caused no damage to any of the plants inside. However the minimum of -1.5 deg C in Jan 2021, caused by a combination of an unusually cold spell outside and low greenhouse soil temperatures, did cause one fatality: the mango. (this was a speculative long shot in any case, ah well….)