Independent reference system shows airport station reporting temperatures up to 3°F warmer than nearby properly sited station
SCHAUMBURG, IL (March 10, 2026) – A new analysis by The Heartland Institute finds that the official temperature station at Reno-Tahoe International Airport consistently records warmer temperatures than a nearby properly sited reference station, demonstrating how station placement and local surroundings can introduce measurable bias into surface temperature records.
This is particularly important because Reno is often cited as “the fastest warming city in the United States,” with the blame being placed squarely on climate change. The official National Oceanic and Atmospheric Administration (NOAA) station in Reno for climate observations is called an Automated Surface Observing System (ASOS) station, and is located between runways at the airport.
The report, Global Open Atmospheric Temperature System (GOATS): What Was Accomplished in Reno, [add hotlink to document] presents the results of a two-year side-by-side comparison between the airport’s ASOS station and an independently operated state-of-the art reference station designed to meet strict siting standards.
The comparison shows that the airport ASOS station – surrounded by pavement, runways, and infrastructure – measured significantly warmer temperatures than the GOATS station located just 1.1 miles away on a properly sited grassy area free from nearby heat-retaining surfaces.
“These measurements demonstrate that station placement alone can introduce a meaningful warm bias into reported temperature data,” said Anthony Watts, senior fellow for environment and climate at The Heartland Institute and creator of the Global Open Atmospheric Temperature System (GOATS). “When thermometers are placed near heat-retaining surfaces such as asphalt and buildings, they measure the temperature of that environment—not necessarily the broader atmosphere.”
Two Years of Parallel Measurements
The GOATS reference station was installed in December 2023 near Reno-Tahoe International Airport, with the permission of the airport authority, and collected nearly two full years of measurements in parallel with the official airport station.
Researchers compared daily high (Tmax), daily low (Tmin), and daily average (Tavg) temperatures across 2024 and 2025. The results showed a consistent pattern: The official airport station reported warmer temperatures on the vast majority of days.
Average temperature differences between the official ASOS station and the GOATS station were as follows:
2024
- Daytime highs: +1.35°F
- Nighttime lows: +2.91°F
- Daily average: +2.13°F
2025
- Daytime highs: +0.64°F
- Nighttime lows: +2.20°F
- Daily average: +1.42°F
The airport station reported warmer nighttime temperatures on more than 90 percent of nights during both years of measurement.
Nighttime Temperatures Show the Largest Difference
Researchers found the greatest contrast between stations in overnight minimum temperatures. This pattern is a classic indicator of the Urban Heat Island (UHI) effect, in which heat absorbed by pavement, concrete, and nearby infrastructure during the day is released slowly overnight.
Because climate datasets often rely on daily average temperatures – calculated using the daily high and low – elevated nighttime temperatures can significantly influence long-term climatic temperature records.
“Urban heat island effects are well documented,” Watts said. “The Reno experiment shows how strongly these effects can influence measurements when instruments are placed near artificial heat sources.”
Confirmation of Earlier National Findings
The Reno experiment builds on the findings of The Heartland Institute’s 2022 report “Corrupted Climate Stations: The Official U.S. Surface Temperature Record Remains Fatally Flawed,” which documented widespread siting issues among official U.S. weather stations.
Unlike earlier surveys that examined station placement, the Reno experiment provides direct side-by-side measurements taken under identical weather conditions.
“This project provides a real-world demonstration of how microsite exposure affects the temperatures being reported,” Watts said. “It shows that measurement integrity must be examined before drawing conclusions about long-term climate trends.”
Implications for Climate Data and Policy
Surface temperature measurements play a significant role in shaping public discussions about climate trends and informing energy, environmental, and infrastructure policies.
The report concludes that station placement and microsite exposure should be explicitly evaluated during climate data audits and policy assessments.
“If temperature stations are influenced by nearby heat sources, those effects must be understood and accounted for,” Watts said. “Otherwise, policymakers risk basing decisions on measurements that include localized heat contamination.”
About GOATS
The Global Open Atmospheric Temperature System (GOATS) is an independent surface temperature measurement network modeled after the National Oceanic and Atmospheric Administration’s United States Climate Reference Network (USCRN), the federal government’s highest standard for low-bias temperature measurement.
GOATS stations employ triple-redundant sensors, proper solar radiation shielding, and strict siting standards to minimize the influence of nearby artificial heat sources. They record temperature every minute and publish data openly without adjustment.
Reno, Nevada local TV veteran Mike Alger was instrumental in getting permission to place the GOATS station on airport property adjacent to the airport to ensure proximity. He had this to say after reviewing the results:
“For decades, I have suspected the temperatures at the Reno airport skewed significantly higher due to Urban Heat Island effect. This study very clearly shows that UHI is not only present, but dramatically present. The use of temperature records from this station, and many others like it, must be re-examined when it comes to assessing climate temperature history.”
Read the Report
The full report, “Global Open Atmospheric Temperature System (GOATS): What Was Accomplished in Reno,” is available here. Full data is available here. A technical whitepaper of the GOATS project is available here.
If you’d like to interview Anthony Watts, please contact Heartland’s Jim Lakely at [email protected] or call/text 312-731-9364.
The Heartland Institute is a national free market think tank founded in 1984 that The Economist magazine called “the world’s most prominent think-tank promoting skepticism about man-made climate change.”
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