Alert for frost
What is the best way for me to know if there will be frost in my area on any given night I have the free version but would gladly pay/buy if that will give me an alert that frost is possible over night I have lost my fruit trees the last two years to frost.
The free version of Windy provides air temperature with a 3h time step. This is not precise enough to assess the risk of frost for your trees. The Premium version would be better with a hourly temperature prediction. 1°or 2° below zero during one hour could make damages to your trees.
Windy gives the possibility to refine the risk assessment of frost. This risk depends on:
Temperature: air temperature at 2m
Humidity: air with high content of water vapor prevents quick night cooling, because it reduces the infrared radiation from the ground.
Dew point: it is the temperature at which the dew forms. The lower this temperature is predicted, the higher is the cooling expected. If this temperature is negative, the risk of freezing will be really high.
Clouds: cloudiness reduces the infrared radiation from the ground and thus the risk of frost. Clear sky at night increases the risk of frost.
Cloud height: low clouds are more efficient to reduce to risk of frost than high clouds.
Wind: the wind blows the cold air near the soil, mix it with the layers above and decreases the risk of frost.
Note the alert tool in Windy is not able to warn you with a good precision. You must check everyday the temperature forecast at the end of the night at your location.