SEARCH BLOG: GLOBAL WARMING
Present weather from the local weather site - shows the current temperature and the forecasted high temperature.
Temperature reading taken at 6:05 p.m. [7 minutes earlier than the screen print above] from our southern facing porch with thermometer 5 feet from the house:
Certainly, you can argue that this thermometer is not as accurate as a weather site device, but it has been calibrated to our electronic thermostat in the house, so it is reasonably close.
I would have to say that a 10-degree difference is not a reasonable difference. Since I am working within my porch, I can attest that it is no where near 90 degrees as being reported by the weather site. Another local site reports 88 degrees right now.
So, the question I pose is just where those weather sites located that they are 8-10 degrees warmer than my southern-facing porch? Perhaps surrounded by asphalt and traffic? Urban Heat Island effect in action?
UPDATE... on an almost real-time basis....
The reported temperature dropped 4 degrees in one hour. The porch thermometer has remained the same at 80 degrees.
Should I suspect that the weather sites are being affected by the sun and immediately surrounding conditions... or that my thermometer is broken and stuck at 80 degrees?
LAST UPDATE... it's now 3 hours after the initial readings. The sun has just set so any solar gain is not affecting readings. There may be some residual heat from surroundings.
My porch thermometer reads 77 degrees. That's a two degree variance which could be attributable to the 15 acres of park adjacent to my property versus whatever conditions are at the nearby weather site.
My porch is screened on 3 sides and the roof has an 8 inch overhang which keeps the thermometer shaded and lightly vented. The thermometer is situated on the eastern side of the porch about 8 feet above the ground outside.What does this prove?
While you can dispute the accuracy of my thermometer, I suggest that it demonstrates that the Urban Heat Island effect may be in play here and affecting the readings taken for both my community and the adjacent community. Whether the actual difference was 8-10 degrees or 3-4 degrees is really not the point. The point is that, even giving back 5 degrees as an error in my thermometer (which I don't believe is the case), it is quite possible that the equipment where the reported readings were taken may be poorly situated for accurate readings.
This is an experiment that any of you can do for your communities with a similarly situated thermometer.
This from Climate Audit corresponds to my experience. This morning, the air temperature as measured on my porch was 65 degrees. This is the weather station temperature: