i read that professional weather stations are about 5 feet off the ground and have to be shielded from wind and rain, so does that mean if you have a common standard or digital thermometer on the ground under an open sky, temperatures can fluctuate a lot being affected by the wind chill, evaporation of water, and the ground losing heat during the night? i am getting readings much different (colder) than what is being reported live from neighboring weather stations in my town, (i look at weather underground’s live radar map). supposedly the difference between the air temperature at ground level can be much colder than the air at 5 feet above the ground, by as much as 10 degrees F, which is about what i am getting. you’d assume the fully exposed thermometer on the ground, same level as where your plants are would be the most accurate reading, but what is really the most accurate temperature? the previous two nights i kept a digital and a standard thermometer next to each other on the patio, they both had the same readings. last night, i put a wagon out on my patio, i put one standard thermometer inside the wagon exposed to the open sky above and then a digital thermometer underneath the wagon (on a plastic plate) so that it wouldn’t be exposed to open sky, yet still be exposed to air around the sides of the thermometer. the one in the wagon was about 5 degrees colder than the one underneath the wagon. which temperature is more accurate? the lowest reading from the digital thermometer (underneath the wagon) early this morning was 25F and the weather channel reported a low of 28F for my town. i don’t know what the lowest reading was on the standard thermometer inside the wagon, i am guessing it was much colder than 25F. i realized i should have put a digital one in there as well so the reading could’ve been on my weather station to compare the two.
This is just the nature of instrumentation.
You can’t directly compare your readings to the readings from the weather station for all the reasons listed
Is the weather station temp closer to what you plants actually experience or is your thermometer?
You’re using these readings to determine when to cover what plants right?
If plant X takes damage at 20°, for instance, you need to ask the question HOW did they determine it was 20°?
Was it based on a nearby weather station reading 20° and the plant took damage, was it 20° on the plant surface as taken by an infrared thermometer?
I suspect the answers vary wildly and that causes the range of temperatures at which a given plant takes damage to vary as well
So basically the answer is to use one and stick to that and see how your plants react and then you’ll know the relationship between the temperature readings and the actual impact on your plants
Sorry there isn’t a real answer
I use these in the yard and indoors in the pot. They are going good for last 3 years. Nice thing is that they have a LCD display and you can also setup data logging with additional equipment from the same company.
https://www.amazon.com/ECOWITT-Temperature-Waterproof-Digital-Display/dp/B0991STVNX