Cumulus Support

How come almost all of the local to me stations, on the various sites, agree with my systems air temperature within +/- one degree C at 29C, yet the more official stations indicate much lower temperatures, nearer to 24C? It is not solar radiation, because it is overcast, besides my sensor is in a double Stevenson screen. It also feels like 29C and a second outdoor thermometer agrees closely with it.

Microclimate maybe?

I'd agree microclient. the "official" stations tend to be in open grassy areas (airfields, or rural), whereas UK amateur stations are usually suburban or semi-suburban

... but harrys location is rural - however when I checked earlier against the 'popular' rather than 'offical' met sources they were more in accord with 'H'

..and inline now at 05:06 official 19C as reported 05:00 my graph at 05:00 shows 19.2C.

The big differences I was seeing during the hotter parts of the days. Numerous other private stations agreeing generally with my temperature, but wildly different (lower) from official sources.

Hmm, I don't have the exact location, but according to WU, not that rural afai can see, in a suburban estate with a car park not too far away? Certainly not open fields.

If your station is in a suburban back garden the nearby houses generate a lot of heat. My maxima is always 1-2C higher than Manchester Airport - 3 miles to the west.

In the very cold winter of 2010 my overnight minima was -11C but 2 miles away at my very open and rural work car park my car thermometer registered -15 but at Woodford aerodrome (3 miles away) the Met Office station located at the bottom of a long slope registered -18C.

That shows how much heat is generated in surburban areas. It's not wrong, just micro climate as others have said.

Mine is usually pretty close to my local airport temperature..usually within a degree or so. The humidity, due to my microclimate is always higher. Here's what my siting looks like.

Red circle is my ISS placement/anemometer placement.