{"id":228425,"date":"2022-11-10T18:30:48","date_gmt":"2022-11-10T17:30:48","guid":{"rendered":"https:\/\/climatescience.press\/?p=228425"},"modified":"2022-11-10T18:30:54","modified_gmt":"2022-11-10T17:30:54","slug":"the-warming-that-happens-in-vegas-stays-in-vegas","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=228425","title":{"rendered":"The Warming that Happens in Vegas, Stays in Vegas"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

Now that I\u2019m back to researching the surface air temperature record and the Urban Heat Island (UHI) effect, I decided to revisit the temperatures in Las Vegas, Nevada. It\u2019s been over 8 years since I posted<\/a> about Las Vegas being the poster child for the UHI effect and I showed some warming trend calculations from the hourly temperature data at McCarren International Airport (now Harry Reid International Airport\u2026 not kidding) which suggested that much of the warming there has been from the urban heat island, not global climate change.<\/p>\n\n\n\n

And this is the trouble with monitoring global climate trends \u2014 most of the land data are gathered where people build things\u2026 increasingly so. In June of last year, The Guardian<\/a>, predictably, conflated the urban heat island effect with climate change when it stated,<\/p>\n\n\n\n

\u201cDriven by the climate crisis and intensified by the city\u2019s expansive growth, Vegas is already cooking \u2014 and it is going to get worse.\u201d<\/em><\/p>\n\n\n\n

Many people don\u2019t really make a distinction between the two. It is reasonable to ask the question, how much has the region around Las Vegas warmed in the last several decades, compared to in the city itself? The trouble is that there are few hourly temperature measurement locations with data extending back at least 50 years in the region that are rural in nature. The area is, after all, a desert, and people don\u2019t usually choose to live in such locations.<\/p>\n\n\n\n

I computed 50-year trends for Las Vegas and for a rural Nevada station, Winnemucca from 24-hourly data, which allows us to see how the trends change with time of day. I did this for the warmest half of the year, April through September. The following plot shows a remarkable feature\u2026 the strong warming in Las Vegas has been entirely at night. Winnemucca shows the background climate signal, with fairly uniform (and weak) warming trends throughout the day. But the impervious surfaces in Vegas \u2014 buildings, concrete, asphalt \u2014 absorb more sunlight during the day than the surrounding desert, and then at night release that heat into the air.<\/p>\n\n\n\n

<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

Part of the reason this happens is the albedo of the city is lower than that of the surrounding desert (thanks to Anthony Watts for reminding me of this). But at least as important is that fact that concrete has a thermal conductivity 9 times as large as sand does, so when it is heated by the sun, much more energy is stored down into the pavement. Sand would have gotten exceedingly hot, but just at the surface, and the extra energy would radiate away (infrared) as well as drive stronger atmospheric (dry) convection which would carry that heat away during the daytime.<\/p>\n\n\n\n

Why would such a thing not show up during the day just as well? Because turbulent mixing driven by a strong super-adiabatic lapse rate near the surface spreads the heat up through the atmosphere and cooler air comes down to replace it, cooling the city during the day. But then at night, a temperature inversion forms, and the lowest levels of the atmosphere no longer exchange energy convectively with higher altitudes. In effect, the strong nighttime inversion that naturally occurs in the desert has weakened over the city as the pavement releases the extra energy it has stored during the day.<\/p>\n\n\n\n

The actual background climate warming in the last 50 years in Las Vegas (whatever its cause), based upon the above plot, looks to be around 0.25 deg. C\/decade. This is also part of the reason why it is important to monitor global temperature trends with satellite measurements of the deep troposphere \u2014 it provides a more robust measurement that is not as influenced by surface effects, such as the Urban Heat Island, and avoids conflation of Las Vegas heat with the \u201cclimate crisis\u201d.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

<\/p>\n\n\n\n

via Roy Spencer, PhD.<\/mark><\/em><\/strong><\/p>\n\n\n\n

November 10th, 2022, by Roy W. Spencer, Ph. D.<\/p>\n\n\n\n

The Warming that Happens in Vegas, Stays in Vegas \u00ab Roy Spencer, PhD (drroyspencer.com)<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

It is reasonable to ask the question, how much has the region around Las Vegas warmed in the last several decades, compared to in the city itself? <\/p>\n","protected":false},"author":121246920,"featured_media":228435,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_crdt_document":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[],"class_list":{"0":"post-228425","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","9":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/0LasVegas.jpg?fit=1920%2C1080&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-Xqh","jetpack-related-posts":[{"id":229085,"url":"https:\/\/climatescience.press\/?p=229085","url_meta":{"origin":228425,"position":0},"title":"No, E&E News, Climate Change Has Not Caused Reno\u2019s Rapid Warming","author":"uwe.roland.gross","date":"14\/11\/2022","format":false,"excerpt":"There\u2019s some truth in that claim about the warmer temperatures since 1970, but the claim of it being \u201cintertwined with climate\u201d is absolutely false.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-479.png?fit=1200%2C782&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-479.png?fit=1200%2C782&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-479.png?fit=1200%2C782&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-479.png?fit=1200%2C782&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-479.png?fit=1200%2C782&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":271495,"url":"https:\/\/climatescience.press\/?p=271495","url_meta":{"origin":228425,"position":1},"title":"OilPrice.com Contributor Misses the UHI Influence on Phoenix Warming Trend","author":"uwe.roland.gross","date":"04\/08\/2023","format":false,"excerpt":"A recent article posted at Oilprice.com claims that recent warming trends in Phoenix, Arizona are due primarily to increasing atmospheric carbon dioxide levels in the atmosphere. This is false. Data show that the high levels of warming, especially at night and as measured at an airport, are primarily due to\u2026","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0tuft-and-needle-phoenix-midtown.jpg?fit=1200%2C800&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0tuft-and-needle-phoenix-midtown.jpg?fit=1200%2C800&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0tuft-and-needle-phoenix-midtown.jpg?fit=1200%2C800&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0tuft-and-needle-phoenix-midtown.jpg?fit=1200%2C800&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0tuft-and-needle-phoenix-midtown.jpg?fit=1200%2C800&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":407122,"url":"https:\/\/climatescience.press\/?p=407122","url_meta":{"origin":228425,"position":2},"title":"The Guardian Is Wrong: Cities Are Hotter Because of the UHI Effect, Not Increased CO\u2082","author":"uwe.roland.gross","date":"08\/10\/2025","format":false,"excerpt":"The Guardian published an article, \u201cWorld\u2019s major cities hit by 25% leap in extremely hot days since the 1990s,\u201d asserting that global warming has caused a sharp rise in the number of extremely hot days in cities worldwide, citing an International Institute for Environment and Development analysis that claims urban\u2026","rel":"","context":"In \"1540 megadrought\"","block_context":{"text":"1540 megadrought","link":"https:\/\/climatescience.press\/?tag=1540-megadrought"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/10\/0AQPKDRdw0NUnHkE5lEr4_zU5Od109A6VZuKSZb7d9ssAuE9rQRwSdrBWJqxKvZ7YHap1bJ-lm4Yy8L9oX72OAw9rW1g20gvm-mxuJWuDwv6VlgisSfWisgrHjDi3yZmB-1.jpeg?fit=1200%2C648&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/10\/0AQPKDRdw0NUnHkE5lEr4_zU5Od109A6VZuKSZb7d9ssAuE9rQRwSdrBWJqxKvZ7YHap1bJ-lm4Yy8L9oX72OAw9rW1g20gvm-mxuJWuDwv6VlgisSfWisgrHjDi3yZmB-1.jpeg?fit=1200%2C648&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/10\/0AQPKDRdw0NUnHkE5lEr4_zU5Od109A6VZuKSZb7d9ssAuE9rQRwSdrBWJqxKvZ7YHap1bJ-lm4Yy8L9oX72OAw9rW1g20gvm-mxuJWuDwv6VlgisSfWisgrHjDi3yZmB-1.jpeg?fit=1200%2C648&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/10\/0AQPKDRdw0NUnHkE5lEr4_zU5Od109A6VZuKSZb7d9ssAuE9rQRwSdrBWJqxKvZ7YHap1bJ-lm4Yy8L9oX72OAw9rW1g20gvm-mxuJWuDwv6VlgisSfWisgrHjDi3yZmB-1.jpeg?fit=1200%2C648&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/10\/0AQPKDRdw0NUnHkE5lEr4_zU5Od109A6VZuKSZb7d9ssAuE9rQRwSdrBWJqxKvZ7YHap1bJ-lm4Yy8L9oX72OAw9rW1g20gvm-mxuJWuDwv6VlgisSfWisgrHjDi3yZmB-1.jpeg?fit=1200%2C648&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":267979,"url":"https:\/\/climatescience.press\/?p=267979","url_meta":{"origin":228425,"position":3},"title":"The Urban Heat Island Effect in GHCN Station Temperatures: Urban Locations show Large Spurious Warming Effects","author":"uwe.roland.gross","date":"17\/07\/2023","format":false,"excerpt":"It has been a while since I have posted progress on our DOE-funded research into the Urban Heat Island (UHI) effect in the GHCN station temperatures used to monitor land-based global warming. It should be remembered that everything I post on this subject is (as is usually the case) a\u2026","rel":"","context":"In \"GHCN station temperatures\"","block_context":{"text":"GHCN station temperatures","link":"https:\/\/climatescience.press\/?tag=ghcn-station-temperatures"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/07\/03_urbanheatisland.webp?fit=1024%2C552&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/07\/03_urbanheatisland.webp?fit=1024%2C552&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/07\/03_urbanheatisland.webp?fit=1024%2C552&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/07\/03_urbanheatisland.webp?fit=1024%2C552&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":280654,"url":"https:\/\/climatescience.press\/?p=280654","url_meta":{"origin":228425,"position":4},"title":"Summer warming 1895-2023 in U.S. cities exaggerated by 100% from the urban heat island effect","author":"uwe.roland.gross","date":"27\/09\/2023","format":false,"excerpt":"We are now getting close to finalizing our methodology for computing the urban heat island (UHI) effect as a function of population density, and will be submitting our first paper for publication in the next few weeks. I\u2019ve settled on using the CONUS (Lower 48) U.S. region as a demonstration\u2026","rel":"","context":"In \"1895-2023\"","block_context":{"text":"1895-2023","link":"https:\/\/climatescience.press\/?tag=1895-2023"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/01895-2023-CONUS-JJA-time-series-for-blog-post.jpg?fit=1200%2C675&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/01895-2023-CONUS-JJA-time-series-for-blog-post.jpg?fit=1200%2C675&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/01895-2023-CONUS-JJA-time-series-for-blog-post.jpg?fit=1200%2C675&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/01895-2023-CONUS-JJA-time-series-for-blog-post.jpg?fit=1200%2C675&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/01895-2023-CONUS-JJA-time-series-for-blog-post.jpg?fit=1200%2C675&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":281145,"url":"https:\/\/climatescience.press\/?p=281145","url_meta":{"origin":228425,"position":5},"title":"Summer in the City, 2023: Record Phoenix Warmth Not Reflected in Surrounding Weather Station Data","author":"uwe.roland.gross","date":"29\/09\/2023","format":false,"excerpt":"From \u00a0Roy Spencer, PhD. September 29th, 2023 by Roy W. Spencer, Ph. D. Ah, the 1960s. Even in 1966, before global warming was a thing, The Lovin\u2019 Spoonful was\u00a0singing about\u00a0(among other things) the unusual heat of the inner city. In fact, the heat caused by urban environments was discussed way\u2026","rel":"","context":"In \"2023\"","block_context":{"text":"2023","link":"https:\/\/climatescience.press\/?tag=2023"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00urbanheatisland.jpg?fit=1200%2C648&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00urbanheatisland.jpg?fit=1200%2C648&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00urbanheatisland.jpg?fit=1200%2C648&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00urbanheatisland.jpg?fit=1200%2C648&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00urbanheatisland.jpg?fit=1200%2C648&ssl=1&resize=1050%2C600 3x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/228425","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/users\/121246920"}],"replies":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=228425"}],"version-history":[{"count":7,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/228425\/revisions"}],"predecessor-version":[{"id":228436,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/228425\/revisions\/228436"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/media\/228435"}],"wp:attachment":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=228425"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=228425"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=228425"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}