Premium weather stations have shielded areas for temperature and humidity sensors to keep them dry, but still have free flowing air across them, the Davis Vantage Pro2 for example.
The sub £125 range of weather stations tend to have small stand alone sensors that you hang on a wall or just place on a wind ledge. But did you know that without placing these carefully, you could well be reducing the life of these by years?
All of the little white box sensors from Oregon Scientific, Ventus, Bresser, TFA and GARNI are 'splash proof'. This means that they will withstand the occasional splash of rain from mother nature and should not be placed anywhere where they will suffer constant rain on them.
A sign that a sensor is becoming waterlogged would initially be that your humidity readings would rise and stay at 90-100% even on a dry crisp or warm day. That's the time to check the sensor isn't wet and to bring it inside without the batteries in and let it sit somewhere warm for 48 hours to completely dry out. We recommend this to anyone that asks about a replacement sensor that is reading incorrectly and they think has failed.
- Ideally these sensors need to be located as follows:
- Height around 1.5 meters (5 feet) above the ground
- Place on a North facing wall to avoid direct sunlight
- Place under the shelter of a porch or building eave
- Avoid standing on a ledge that will get wet leaving the sensor sitting in water
Not everyone can have a 100% ideal location and some customers have come up with their own ingenious ideas, especially as far as keeping the rain off the sensor. An upturned white plastic pot over the top of the sensor (think margarine / yoghurt) with the bottom left open to allow for free circulation works well.
Please do let us know what idea's you've come up with and now you know why we recommend the 48 hours drying of sensors.