2025 was the third hottest year on record

I'm not sure i know the exact locations, but NASA and NOAA do, and people who have seen the data and locations (and therefore know what is rural or not) say things like this about realclimate.org's handwave of UHI:

> "Because urban areas still only represent 3-4% of the global land surface, this should not substantially influence global temperatures.

> However, most of the weather stations used for calculating the land component of global temperatures are located in urban or semi-urban areas. This is especially so for the stations with the longest temperature records. One reason why is because it is harder to staff and maintain a weather station in an isolated, rural location for a century or longer."

further from a paper critiquing the GHCN model's homogenization algorithm:

> "When they were compiling the Global Historical Climatology Network dataset, the National Climatic Data Center included some basic station metadata, i.e., data describing the station and its environment. For each station, they provided the station name, country, latitude, longitude and elevation. They also provided a number of classifications to describe the environment of the station - whether it was an airport station or not; if it was on an island, near the coast or near a lake; and what the average ecosystem of the stations’ surroundings was, e.g., desert, ice, forest, etc"

oh and an interesting note, if you are wondering "well, how many fully rural stations do we have data for at least 95% of the 'last 100 years?"

eight.

globally.

i'm literally in the middle of trying to parse a couple of papers that examine the methodology of at least the NOAA homogenization model.

did you know there's only eight sensors, globally, that we have data for >95% of the last 100 years, that are labelled as "fully rural"? so this means that 99.9% of the stations must therefore be, at least, more likely to be adjusted, doesn't it? The entire premise that UHI is irrelevant because they "normalized" the 99.9% and it showed it was irrelevant is... i don't know, it's something, though.

I agree it's suspicious. Rather than dismiss it altogether, I'm trying to understand the e2e process. i.e. divide 1880-present into Epochs and understand what %-age of coverage, resolution & how precise were the instruments

after you do all of that, see if you can find pictures of the stations, the little structure the old ones were in are called "CRS" which stands for Cotton Region Shelter. these were the old liquid-in-glass style thermometers. The new ones have multi-plate radiation shields to house the thermistor and protect it from direct sunlight while allowing airflow. i guess some people say they look like a beehive, but they're a cylinder.

so the CRS ones could be put anywhere. the new MMTS sensors had a pre-cut length of cable for installation, as the base unit was to be situated indoors.

So CRS could be out in the middle of a field, where the MMTS are generally within 30' of a building.

Maybe we should throw out all the MMTS data?

Now, though, someone finally realized, and they're installing wireless MMTS - minimum-maximum temperature sensor, tells the min and max over the last 24 hours, and you record those numbers once per day, at a specific Time-of-Observation. Changing the time-of-observation requires de-biasing the data, too!

i went and got the raw data, wrote some code to parse it and then process it, and my results:

MMTS locations are so close to heat sources and heat sinks, at least in the US, that any sort of debiasing appears to be a "guess."

statistically. 96% of them. thankfully NWS/NOAA/NASA/etc have started deploying wireless sensors, but unless they admonish the volunteers for placing their (NWS/NOAA/etc) dumb MMTS designs so close to heat sinks and sources, as if it was their fault, demanding that volunteers move the sensors to a location 20 meters from said sinks and sources...

you're just gunna have and continue to have decades of literally unusable data. But hey, hottest year on record!

I am not mad at volunteers. it isn't their fault the MMTS devices only came with 10 meters or whatever of cabling for the indoor-outdoor data. I would, however, like to see the rationale and meeting notes and design documents (and the reasoning and arguments thereof) for the MMTS; explicitly for use tracking climate trends.

anecdote: i have multi channel humidity and temp sensors that log to SD card. they have been logging for a long time. My outdoor sensors, as well as our cars, etc, show that our location is always 7F cooler than the nearby metro (20 miles) during the warm months. If we used my temperature data, i'd believe the trends. if we use the temperature data from the sensors they use at the airport, it's going to show warming - and i submit you can't de-bias that using the methods used for the IPCC and other reports. and when i say 7F cooler here than there, i mean on the thermometers on our cars (and multimeters, or even a liquid-in-glass carried around!). I also mean my location is consistently cooler than the forecast temperatures for the city.

i understand weather is not climate.