How not to measure Temperature, part 46. Reno's USHCN Station

Last summer I attempted to do a survey of Reno’s USHCN official climate station. But I was thwarted by its placement at the Reno International Airport due to security and lack of accessible photographic vantage points. Reno’s USHCN station is particularly important due to it being part of the test cases of stations in the new USHCN2 scheme being implemented by NCDC. It’s also important due to it’s steep temperature trend which appears to be more of an urban heat island issue than a climate change issue. It shows up as a hot spot in USHCN contours done by Steve McIntyre.


While there wasn’t good Google Earth photography online last summer, that has since been remedied, and high resolution photographs are now available at Google Earth and at Microsoft’s Live Earth. Having these, I was able to complete the station survey and determine that this station is a CRN4 rating due to proximity to the ILS building with a/c exhaust vents, less than 10 meters away. A CRN4 rating is unusual for an ASOS station.


The Reno USHCN ASOS station undergoing repair, looking west. 

(HO83 hygrothermometer repair perhaps?)

The Reno USHCN station is in the middle of the runway complex, between runways 16L and 16R. And what is interesting about that placement is that it seems the color/albedo of the surface where it is located is actually darker with a lower albedo than than of the nearby runways as shown below.

Reno NV ASOS aerial wide 

You can see a complete photo collection of the Reno USHCN station here.

In wondering about just how this placement between runways on a darker surface environment might contribute to the upward trend in the GISS temperature graph shown above, I did some searching online and soon discovered that NOAA uses Reno’s placement problems as an example in a training manual for climate monitoring COOP managers. They’d already done all the work for me! More on that internal NOAA training manual later, as it has provided a wealth of information previously undisclosed.

What was amazing is that they’d already determined that there were significant problems with this USHCN station placement that contributed a significant warming bias to the record.

From that manual:

Reno’s busy urban airport has seen the growth of an urban heat bubble on its north end.

The corresponding graph of mean annual minimum temperature (average of 365 nighttime

minimums each year) has as a consequence been steadily rising. When the new

ASOS sensor was installed, the site was moved to the much cooler south end of the

runway. Nearby records indicate that the two cool post-ASOS years should have been

warmer rather than cooler. When air traffic controllers asked for a location not so close

to nearby trees (for better wind readings), the station was moved back. The first move

was documented, the second was not. The climate record shows both the steady warming

of the site, as well as the big difference in overnight temperature between one end of this

flat and seemingly homogeneous setting, an observation borne out by automobile

traverses around the airport at night.

They were also kind enough to provide a photo essay of their own as well as a graph. You can click the aerial photo to get a Google Earth interactive view of the area.


This is NOAA’s graph showing the changes to the official climate record when they made station moves:


Source for 24a and 24b: NOAA Internal Training manual, 2004-2007

What is striking about this is that here we have NOAA documenting the effects of an “urban heat bubble” something that Parker 2003 et al say “doesn’t exist“, plus we have inclusion a site with known issues, held up as a bad example for training the operational folks, being used in a case study for the new USHCN2 system.

It seems that Parker is looking more and more foolish with his attempts to make UHI “disappear” when NOAA references UHI problems with station placement in their own training manuals.

I’ll have more on revelations from this internal training manual from NOAA coming soon, plus I have my Paint Experiment Data collated, and I’ll be publishing results of that Latex -vs- Whitewash likely over the weekend.

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January 10, 2008 10:52 am

Just to the West of the airport and the I-395 freeway, you can see, in the satellite photo, significant “strip” style development along “old 395” and cross streets. As anyone familiar with that area knows, much of that growth has been since the late 1970s. Prior to that, other than a few modes of “leapfrog” type development, there were mostly open plots of land there. The relatively recent completion of that leg of the 395 freeway has actually exacerbated the strip development in that southerly direction and most parcels have now been built out. One must also note the extensive warehousing / logisitcs / light industrial development literally beginning at the eastern fence of the airport and spanning across the valley to the foothills, also of relatively recent origin.

January 10, 2008 1:35 pm

This is rather unrelated, but I keep seeing the temperature graphs like the one at the top of the post for USHCN stations. Where are these available? Are they somewhere on the NOAA site?

Evan Jones
January 10, 2008 2:37 pm

Night light,
Light bright,
First light I’ve seen tonight.
Adjust it left, adjust it right
Till I sight the site I cite.
Hubble, Bubble, tar and rubble
Tarmac warm and T-min double.

Leon Palmer
January 12, 2008 11:19 am

Hi Andrew,
It would be interesting to plant a weather station at the southern location they used for those two years to continue to track the temperature difference between the south and north locations…

March 2, 2008 1:38 pm

This is pretty late for this thread, but I have a couple of questions.
I live in the Reno area (west side on the foothills) and it is very apparent that the official records don’t reflect the weather here–about 3-5 miles from the airport. I’m only about 500 feet higher than the airport, but the temperatures are colder and the area gets over twice as much snow.
Since I assume the primary goal of these stations is to provide accurate information for pilots, it’s a good thing the station is right between the runways–and with that limitation, should not be used to model climate change.
However, even if the end result is that the temperatures recorded are far higher than the surrounding area–should they not be consistent? By that I mean the temperature records may not be accurate, but they will be precise. If the station has been located on asphalt between two runways for the last 40 odd years, the higher temperatures should be varying between a mean that is roughly constant. I’ve only been here a couple of years–the town may have grown a lot, but if the area covered by the airport is constant, why are the recorded temperatures increasing overall? They should have jumped up when the station was moved to it’s present location, and then varied around a flat mean roughly 6 – 8 degrees above the true temperature of the surrounding countryside. But the chart shows increasing temperatures. Why?

August 23, 2008 9:04 pm

[…] the UHI factor in one of it’s training course ( NOAA Professional Competency Unit 6 ) using Reno, NV and Baltimore, MD as examples. The Reno station had to be moved because it was producing an […]

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