Originally published on Climate Realism
In a recent article published by E&E News Climate Wire, reporter Scott Waldman claims Reno, Nevada is the fastest warming city in the United States. In this single article, titled “Nation’s fastest-warming city could decide Senate control,” Waldman makes the mistake of conflating climate change, the Urban Heat Island effect (UHI), and politics.
Waldman writes:
“More than almost any other city, Reno’s fate is intertwined with climate politics in Washington. It’s the fastest-warming city in the United States, and is 10.9 degrees Fahrenheit warmer than it was in 1970, according to a July report from Climate Central. (Las Vegas places second, with 5.6 degrees of warming.)”
There’s some truth in that claim about the warmer temperatures since 1970, but the claim of it being “intertwined with climate” is absolutely false. Multiple lines of evidence and data analysis proves it.
First, let’s look at the claim made by Climate Central, the global warming advocacy group Waldman used for his source. Climate Central claims:
- Summer warming was greatest in the western and southwestern U.S. The three greatest increases in summer average temperatures since 1970 were in Reno, Nev. (10.9°F), Las Vegas, Nev. (5.8°F), and Boise, Idaho (5.6°F).
Those cities temperatures have risen dramatically. However, Climate Central completely failed when they tried to attribute the increasing summer temperatures to greenhouse gas increases, saying:
The heat is on. As planet-warming gases from fossil-fuel burning increase global average temperatures, we’re experiencing more extreme heat events. Extreme heat is most apparent in the summer since it’s the hottest time of year.
Waldman and Climate Central blamed greenhouse gases from fossil fuels for the rise in temperatures, without any research or undertaking an analysis concerning the true factors responsible for the dramatic warming in those cities. The UHI is mostly to blame.
As far back as 2008, I discovered that the UHI had compromised Reno’s ground based temperature readings, through a hands-on experiment to determine the strength of UHI on summer nights. Using a calibrated digital thermometer, I drove transects across Reno back and forth at night while measuring air temperature. A clear result emerged from that experiment. My experiment worked so well that there is now a citizen science based program to do driving temperature measurement transects in major cites in the USA.
From the data measured, it became clear that a huge UHI signature existed near downtown and airport. The temperature data used to claim that Reno is the “fastest-warming city in the United States” comes from the automated weather sensor, known as an ASOS, at the city’s airport.
Even the local National Weather Service (NWS) office in Reno acknowledges the problem. They tried to move the airport temperature sensor to a cooler location away from the city generated UHI heat bubble, further south, but were overruled by the Federal Aviation Administration (FAA) who said the temperatures were not representative of conditions on the runway. In a training manual they produced, they said:
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.
…
When air traffic controllers asked for a location not so close to nearby trees (for better wind readings), the station was moved back.
As seen in Figure 2 above (figure24b from the NWS Manual) during the short time the ASOS was moved, cooler temperatures prevailed. Clearly the UHI biases temperatures reported from Reno upward. There was even a peer-reviewed paper written about the issue in which Reno’s airport ASOS sensor moves were shown to cause dramatic shifts in temperature.
Placement near heat sinks and sources, such as tarmac and runways, is one of the most significant problems with temperature data at airports being used to measure climate change. The sensors are placed to give runway conditions for aviation safety – they were never intended for climate use. The data is not fit for that purpose. A 2022 report Corrupted Climate Stations: The Official U.S. Surface Temperature Record Remains Fatally Flawed, found that this problem isn’t just at airports, but at the vast majority of weather stations that are being used to measure temperature.
Further proof that the UHI, not climate change, is driving Reno’s sharply rising temperatures comes from an analysis done by climatologist Roy Spencer, Ph.D. of the University of Alabama at Huntsville, and myself.
Spencer took all of the available hourly temperature data from NOAA’s Integrated Surface Database (ISD) and performed an extensive hour-by-hour analysis seen in Figure 3 below. What he found disproves any significant climate change link to Reno’s temperatures.
To explain the graph.
- The time on the graph is in UTC (also known as Greenwich Mean Time or GMT) because that’s how the data is stored. For Reno, 6AM (dawn in the summer) corresponds to 14 (UTC).
- The graph shows clearly that there are strong summer warming trends in the months of May, June, July, August, and September overnight that disappear right after dawn.
- Conversely, there are no warming trends overnight in the winter months of November, December, January, and February.
- Climate change, which is scientifically agreed as measured over 30 years, is not time selective on an hourly or monthly basis. What we are seeing in Reno is a local UHI effect on summer nights.
If climate change was driving Reno’s temperatures, the rapid rise in temperatures would also be evident in the winter, but Spencer’s analysis clearly demonstrates that it is absent. It is also absent during the daytime.
Additional support for this finding is found in a study produced by the University of Nevada at Las Vegas, “The Urban Heat Island Effect in Nevada.” The March 2020 study, examined the UHI effect in Reno and Las Vegas, the two biggest cities in the state. They found that the UHI is a big problem in Nevada (emphasis mine):
Cities are warmer than surrounding rural areas because they replace open areas and vegetation with pavement, buildings, and other heat-absorbing infrastructure. This phenomenon is referred to as the “urban heat island” effect. The mean annual air temperature in a city with over 1 million residents can be 1.8 – 5.4°F warmer than surrounding areas during the day and over 20°F warmer at night. The heat island effect has worsened over time; today, cities experience ten more “extreme heat events” on average than they did in the mid-1950s.
UHI is also being driven by waste heat from air-conditioning as detailed in a 2014 study by researchers at Arizona State University, titled “Excess heat from air conditioners causes higher nighttime temperatures.” They wrote, “…during the night, heat emitted from air conditioning systems increased the mean air temperature by more than 1 degree Celsius (almost 2 degrees Fahrenheit) for some urban locations,”
Finally, another peer-reviewed study published by the University of Nevada at Reno titled Determining Heat Island Response to Varying Land Cover Changes Between 2004 and 2017 Within the City of Reno, Nevada has a map of satellite derived temperature combined with Landsat imagery. I have annotated it to show the placement of the airport ASOS sensor in Figure 4. It clearly shows the sensor being in the middle of the runways, and by the colors, the warmest part of Reno.
Waldman and Climate Central failed to examine local causes that are clearly driving the dramatic temperature rise in Reno, instead simply choosing the lazy path of uncritically attributing Reno’s rising temperatures to human induced climate change. Tellingly, they cite no evidence for this claim. How could they? There is none.
Waldman and Climate Central chose advocacy over honest journalism and following the science. They should be ashamed of their lack of professionalism.
A fine detailed post supporting what I have experienced such a large change where I have personal experience observing for myself when I leave the metropolitan area to a semi dark sky location just 15 miles north into the rural region at dusk to see a large drop in temperature begins a couple miles north of Pasco where in the fall time in just 15 minutes drop as much as 15 degrees F where in the summer it about half that change.
I also see it every day when I used to drive to work and back to home see firsthand a 1-2 degree F temperature change when I drive through the Yakima delta area between two cities.
It is OBVIOUS that people are lying about this easy to observe phenomenon that I have known by personal experience for many years.
This post is a keeper deserving widespread recognition and I will start that by posting it in my climate area of my forum and suggest that others also generate publicity to this excellent post Anthony writes.
I also see it every day when I used to drive to work and back to home see firsthand a 1-2 degree F temperature change
How does that temperature change differ from 30 years ago. Or is it about the same? If the same, it did not cause local warming.
It was like this DAILY for 7 years saw the same temperature change daily the entire time which indicates the cooling effect of water but not effecting any standard thermometers as they are at airports and a TV News station only where they show inflated temperature readings.
The Yakima Delta is along the edge of the 6-lane freeway on the east side and fully part of the Yakima River that empties into Columbia River in the area.
There is a several miles long linear Columbia Park that is along the Columbia River between Kennewick and Pasco that is always several degrees cooler than just up the hill going south about 500 feet at Union Street area it is why it is a great place to visit when it gets hot as it normally does from June to August expecting 95-105 F every sunny day which is very common.
Simply going east 15 miles to Charbonneau Park means it will be around 3-5 degrees cooler simply because it surrounded by rural setting.
I have lived in the area since 1964, there no climate change at all in my area and no visible change to local steppe flora along parts of the Yakima River either.
I have lived in the area since 1964, there no climate change at all in my area
It would be difficult to notice a small change in the average temperature, especially changes in TMIN at night when most people are indoors sleeping.
Winters are warmer here in Michigan over a 45 years period since I moved here. That estimate is helped by living in the same house since 1987. If I had moved wihin Michigan I might not have noticed, If I had lived in the same home for only 15 years, rather than 35 years, I might not have noticed,
The climate I live in itself hasn’t changed for centuries since it is still a steppe classification according to the Koppen climate classification system.
Mine is classified as BSk now as it was in 1964.
I also see it every day when I used to drive to work and back to home see firsthand a 1-2 degree F temperature change
When I go from my rural property to a town of only 3000 I see as much as a 5F difference.
My outside sensors show anywhere from 1-5F difference between the tree line and my back porch.
What is the standard deviation for a mean of these temperatures? Does anyone really think an anomaly or a mean to the one-hundredths or one-thousandths place adequately describes the variation.
If you don’t have the data, just lie about it. It’s not like the media will ever call you out on it.
When people piss down your back and then tell you it’s raining, unless you turn around and look for yourself you won’t really know, will you?
Waiting for Nick to proclaim that since the station is accurately reporting the temperature of it’s location, there is no problem with using that data to help calculate global warming.
It is obvious tha the ASOS needs to be relocated.
That being said, I am leery of anything that may make approach and landing more difficult for commercial pilots at Reno. It has some of the worst turbulence I have ever experienced; making my family get-togethers at Lake Tahoe much more exciting than necessary!
I believe the intent is that we shouldn’t use airport sensors to try and calculate global average temperatures.
Airport sensors have a purpose, climate network sensors have a purpose.
The purposes are different and hence the priorities regarding siting are different.
The ASOS needs to accurately reflect the actual air temperatures over the runways, because atmospheric temperature is a major determinant of aircraft performance, both in terms of stall speeds as well as engine performance, especially at a high elevation airport (5,050 ft above MSL) like Reno-Stead. In aviation that’s referred to as “density altitude”.
It is one reason why records should be stopped and new ones started. The preoccupation with creating “long” records is driven by statisticians that don’t want to create spurious trends and problems like Simpson’s’s Paradox.
This results in unreasonable massaging of data that causes it’s own problems just like this.
We are going to find that the entire premise of warming caused by GHG’s is bogus. The previous threads here about Japanese temps is just the beginning. Like it or not the temperature data is contaminated beyond redemption. It is on reason I view UAH to be better. And, even it will have some uncertainty from UHI.
Simpson’s paradox? Is that the one that starts with “Take two donuts …”?
Well, I hadn’t heard of that one before. I’m referring to the one that has different trends when using short series vs long series made by combining the short ones.
Good report on an obvious issue, UHI. The downtown development and urban expansion of all three areas mentioned, Las Vegas, Reno, and Boise, has to be seen to be believed. The back-and-forth with FAA and sensor location at the Ren. Airport is by itself damning about temperature increase, unless one believes in a gradient that leads to 150 deg F in equatorial regions. RENO: FUN FACT: the car collection event known as “Hot August NIghts” in Reno has to be on every car aficianados check list. During the event you can also hear open air concerts from oldies like Little Richard, Huey Lewis, and even The JerseyBoys.
The Boise ID region has grown but the urban part not a lot,
except for the airport itself.
The ASOS is here: 43.56704, -116.24053
It appears the area has been cleared with equipment, maybe a disk harrow.
Very elegant multi dimensional illustrations of the reality. Nothing like proper evidence for establishing truth.
Aside from the effects of urban heat island, their data seem to not agree with official NWS data, which show a total warming from 1970 to 2022, using August (hottest month of the year) in Reno average daily temperature, from 71.5 to 78.8 (7.3 deg F). The natural variability year to year of August daily temperatures during the period 1970 to 2022 was from 65 to 79 degrees. That’s a lot of variability!
And everybody knows that the 1970s was a time of sustained worldwide low temperatures that had all the climate scientists and major media fretting over a new ice age. Indeed the temperatures in the 1970s were much lower than in the 1930s, while the CO2 concentration in the atmosphere was far lower in the 1930s (307 ppm) than in the 1970s (330+ ppm).
This year’s November temperatures at the Reno airport will be below the 1985-2015 average.
https://www.timeanddate.com/weather/usa/reno/climate
You can see in July and August a small amount of rainfall, so strong sunshine.
Let’s cross check with the convention and visitors bureau, the paving contractors association, airport traffic data, and the casino revenue reports.
Reno’s population has increased by more than 300% since 1970. It doesn’t take a lot of scientific study to understand that the area of pavement and building rooftops has gone up by at least that much, along with vehicles, air conditioners, and all the other things that contribute to urban heat island effect.
I remember trying to get to a conference in Reno once. It was a disaster starting with the tiny patch of fog over the runway that caused diversion of the flight to Sacramento, followed by a big snowstorm on Donner Pass, and a delayed bus trip over the Sierras to arrive late to the conference. That airport makes its own weather, and I learned the hard way.
I suppose climate change also causes tax- and cost-related outmigration from California too.
This is a well done post. Thanks.
I have one issue:
From this post:
“Climate change, which is scientifically agreed as measured over 30 years, …”
And then from that link:
“To create a climate record, 30 years of weather data is averaged to create a “normal” climate expectation for a location or region. ”
This sort of stuff is not helpful.
Note that the word normal is in quotes, in this case meaning it is a human defined concept, and maybe ought to be in an alien font, Segoe Script perhaps. In tennis, love is a word that represents a score of zero. Silly: right? Prior to the mid-1930s, no one thought of climate as defined as 30-year averages. Now yes, but silly.
30-year averages give a person something to compare the day’s weather to, but that isn’t climate as historically understood.
I live where it is hot and dry in the high sun season while cold with some snow in the winter season.
Here, in central Washington State, the vegetation is the same as it was hundreds of years ago – because the climate is the same.
Will Scott Waldman be told about his bad reporting?
He won’t care. He’s in the business of spreading climate propaganda. If we “deniers” don’t like it, that makes it all the more powerful in his mind.
I just came across this news item. It’s not UHI, but perhaps more an example of how these days UK Green councillors seem to say “because of Climate” without even engaging their brains. It comes from Glasgow (venue for last year’s COP Festival). Ostensibly Drive-Thru McDonalds in Glasgow contribute to Global Warming, presumably including Reno, so apparently Glaswegians must overcome their drive-thru Big Mac habit. In reality the hidden agenda is that Greens have become infiltrated by the hard left who are still battling Capitalism, using Climate Change as a camouflage. Even Saint Greta has dropped the pretence.
Not Reno….but these warm buildings blocking the IR view of the cold sky, is one of the sources of UHI effect.
A very solid post.
There is a bigger background issue than the misattribution by E&E reporters. This post by itself means the surface temperature records are not fit for climate purpose. Yet they are used as if they were. To give just one example. Climate models must be parameterized, and the parameters then tuned to best hindcast 30 years of surface temperature anomaly (a firm, written CMIP required run). This post says that means CMIP models are tuned to run hot because the tuning drags in UHI that has nothing to do with climate change.
The tuning problem noted in my previous models posts was that it also drags in the attribution problem of natural variation. In recent decades, UHI is likely at least as large an issue.
Climate model tuning?
ha ha ha, what tuning?
If there was model tuning, the models would get more accurate over the decades. It seems like the average CMIP6 model is over=predicting global warming even MORE than the average CMIP5 model did !
Computer game prediction ranges were decided in advance to please “management” They were tuned to reflect the 1979 Charney Report for many decades.
Any ECS had to be in the ballpark of +3.0 to +4.5 degrees C., and they always had been until CMIP6, when the acceptable range was arbitrarily changed to about +2.5 to +6.0 degrees C. Except for the Russian IMN model — those pesky Russians at +1.8 degrees C. don’t play the computer game right
A decade or more ago I experimented with a couple of different sensors recording UHI in realtime from my car at various sites in NSW around Canberra.
Two degrees C Urban Heat Island in small village of Barmedman, NSW, Australia 25May2010
http://www.warwickhughes.com/blog/?p=575
Obviously you need calm conditions as wind disperses the UHI – and flat terrain is best to produce a clear signal – any terrain perturbs the data as does a river or watercourse. I have not run any traverses for ten years now.
I looked at the NOAA link and admit to some suspicion that they could easily “blur and confuse” data from multiple sites.
NOAA hands are far from clean in the 30+ years history of the generation of Global Warming data by “cramming in every UHI on planet earth”. And never forget Climategate.
LANGUAGE POLICE REPORT
I wish people would stop blaming local warming on UHI
Warming would require an INCREASE in the UHI effect.
That would most likely result from economic growth in the vicinity of a weather station. Or a move of the weather station to a warmer location.
A weather station at an airport would be affected by an increase in airplane traffic and economic growth around the airport.
Reno population in 1970 = 72,863
Reno population in 2020 = 264,116 (up +364%)
Up +364% ought to increase the UHI effect = local warming
We don’t need a study to assume that.
Washoe County (Reno included) population growth
WC in 1970 = 121,068
WC in 2020 = 477,082 )up +394%
Reno-Tahoe International Airport serves the city of Reno, Nevada, and handles around 4 million travelers annually. RNO Airport is about a 7-minute drive in ideal road and traffic conditions from downtown Reno, which is located 5 miles (8 kilometers) from the airport.
Up by 3.94x, not up by +394%
Up by 3.64x not up by +364%
Anthony,
Here is some pertinent, supplementary reading from 4 years ago. Keep up the good work. Geoff S
https://wattsupwiththat.com/2018/12/20/the-science-of-the-urban-heat-island-effect-is-pathetic-and-misleading/
The biggest fraud is relying on the heat sink “temps” for “scientific” analysis. Why couldn’t the NWS simply position new weather station outside cities’ heat shadow and leave the airport stations in place?
Maybe they’re afraid that real temperatures wouldn’t fit the Demo/Progs’ narrative.
Also, if you find Reno of Google Earth , then zoom out, you will see there are large areas of “not much”.
Yet that Reno measurement will be smeared over all that region.
Hence we get
globalURBAN warming !Changes of UHI, infilling, adjustments, readjustments, homogenization, pasteurization, pulling numbers out of a hat — the surface temperature numbers have every possible source of inaccuracy covered !
Even at night in November, the difference in temperature measurements in Reno is 7 degrees F.
Will it be warmer in the US? No, it will be even colder.
Temperatures in Colorado dropped to -20 degrees Celsius overnight.