{"id":381613,"date":"2025-06-05T18:08:46","date_gmt":"2025-06-05T16:08:46","guid":{"rendered":"https:\/\/climatescience.press\/?p=381613"},"modified":"2025-06-05T18:08:47","modified_gmt":"2025-06-05T16:08:47","slug":"warmer-summers-not-so-fast-axios-nighttime-lows-drive-the-heat-not-daytime-highs","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=381613","title":{"rendered":"Warmer Summers? Not So Fast AXIOS: Nighttime Lows Drive the Heat, Not Daytime Highs"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

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

From ClimateRealism<\/a><\/p>\n\n\n\n

By Anthony Watts<\/a><\/p>\n\n\n\n

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

In their recent article, \u201cAmerica\u2019s summers keep getting warmer,\u201d<\/em><\/a> Axios claims that hotter summers across the U.S. are \u201cone of the clearest ways we experience climate change.\u201d That statement is misleading. The article focuses exclusively on \u201caverage summer temperatures\u201d while ignoring crucial underlying details \u2014 specifically, the difference between daytime highs and nighttime lows. A closer look at the data suggests that rising nighttime temperatures \u2014 not dangerous daytime heat \u2014 are mostly to blame for the modest increase in \u201caverage\u201d temperatures. This pattern is a well-documented signature of the urban heat island (UHI) effect<\/strong><\/a>, not global climate change.<\/p>\n\n\n\n

The entire Axios piece rests on the idea that an increase in average<\/em> temperatures over the past 50 years (from 1970 to 2024) proves human-caused climate change. But here\u2019s the problem: an \u201caverage\u201d can be deceptive. By combining daily high and low temperatures  into one metric, the nuance disappears. And that nuance matters. According to detailed meteorological analysis done by the Environmental Protection Agency<\/a> (EPA), high temperatures (daytime maximums) in the U.S. have remained relatively stable<\/strong>, while low temperatures (nighttime minimums) have been increasing<\/strong>. This skews the average upward without indicating an actual increase in daytime heat \u2014 the kind that poses the most risk to people and infrastructure. This is backed up by the National Oceanic and Atmospheric Administration (NOAA) analysis, Mapping U.S. Climate Trends<\/a>, from the NOAA climate website. This report highlights that nighttime minimum temperatures have warmed at a rate of 1.43\u00b0F per century compared to 0.89\u00b0F per century for daytime maximums during the period 1895\u20132016, illustrating the asymmetric warming trend.<\/a><\/p>\n\n\n\n

\"\"
Summer (June, July August) Maximum Temperatures with trend, from NOAA data. Source: https:\/\/www.ncei.noaa.gov\/access\/monitoring\/climate-at-a-glance\/national\/time-series\/110\/tmax\/3\/8\/1895-2016?trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2016<\/a><\/em><\/figcaption><\/figure>\n\n\n\n
\"\"
Summer (June, July, August) Minimum Temperatures with trend, from NOAA Data. Source: https:\/\/www.ncei.noaa.gov\/access\/monitoring\/climate-at-a-glance\/national\/time-series\/110\/tmin\/3\/8\/1895-2016?trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2016<\/a><\/em><\/figcaption><\/figure>\n\n\n\n

The real-world implication of this divergence is crucial. If daytime highs aren\u2019t increasing substantially, the scare factor vanishes. Nobody complains about slightly warmer nights \u2014 in fact, many people prefer them. But when you average those warmer nights with stable daytime highs, you get the illusion of \u201cclimate change\u201d through rising average temperatures. And that\u2019s precisely the sleight-of-hand Axios<\/em> and their source, Climate Central, are engaging in.<\/p>\n\n\n\n

This divergence was comprehensively documented in recent peer-reviewed research by Dr. Roy Spencer, former NASA scientist and principal research scientist at the University of Alabama in Huntsville. In a 2024 paper published in the Journal of Applied Meteorology and Climatology<\/em>, Dr. Spencer examined the spatial relationship between population density and temperature trends using NOAA data from 1895\u20132023. His findings? The urban heat island effect is the dominant cause of warming in U.S. temperature records<\/strong>, especially in the minimum temperatures that drive up averages. As population increases, more asphalt, buildings, and energy usage trap heat at night, particularly in cities. This is not global warming \u2014 it\u2019s local heat retention caused by development. Spencer\u2019s full paper is available here<\/a>.<\/p>\n\n\n\n

Now, to Axios\u2019s credit, they do briefly<\/em> acknowledge the urban heat island phenomenon, noting that \u201cmany cities suffer from \u2018heat islands\u2019 \u2014 areas of especially high temperatures caused by roads, parking lots, buildings and other heat-trapping features\u201d. But they bury that admission and fail to connect it to the broader implication: if these \u201cheat islands\u201d dominate the temperature increase, then the change is local and anthropogenic in an entirely different sense \u2014 a land-use artifact, not a carbon dioxide crisis.<\/p>\n\n\n\n

This is not a new argument. As we\u2019ve outlined repeatedly at Climate Realism<\/a>, the UHI effect explains much of the warming shown in localized temperature datasets. Yet climate advocacy groups like Climate Central \u2014 heavily cited in the Axios article \u2014 downplay or ignore this effect when it doesn\u2019t serve the narrative. More fundamentally, their own data often supports the skeptical case when viewed critically. For example, they chart average temperatures but omit daily maximum temperature trends \u2014 an omission that speaks volumes.<\/p>\n\n\n\n

Another critical flaw in the Axios article is its lack of statistical scrutiny. The claim that 97% of cities analyzed saw warming since 1970 might sound compelling, but it\u2019s also meaningless without examining how much of that warming occurred in rural versus urban stations<\/strong>. Rural stations, being less influenced by land-use change, would provide a better indicator of climate trends untainted by urbanization. But Axios doesn\u2019t provide that breakdown \u2014 likely because it would undercut the headline.<\/p>\n\n\n\n

Further, the cherry-picked focus on specific cities like Reno (+11.3\u00b0F), Boise (+6.3\u00b0F), and El Paso (+6.2\u00b0F) is another red flag. These cities have undergone dramatic urban expansion and population growth since 1970. Reno\u2019s population has more than doubled; Boise has added tens of thousands of new homes and highways. Of course they\u2019re warmer \u2014 they\u2019ve built over their own thermometers. As we\u2019ve shown at Climate at a Glance<\/a>, genuine climate signals must be filtered through the noise of land use change, otherwise the data is just measuring asphalt\u2019s heat retention effects, not atmospheric temperature increases due to the supposed heating effect of carbon dioxide.<\/p>\n\n\n\n

It\u2019s also worth noting the psychological tactics in the article. Loaded language like \u201chealth risk,\u201d \u201cpregnant women,\u201d and \u201cvulnerable groups\u201d are peppered throughout to provoke emotion rather than provide objective data analysis. The appeal to emotion is a classic rhetorical device used to bypass rational scrutiny. Instead of showing a balanced analysis, Axios jumps straight from a graph of average temperatures to policy implications and public health warnings. That\u2019s advocacy journalism, not science reporting.<\/p>\n\n\n\n

In conclusion, the Axios piece is yet another example of lazy climate reporting masquerading as fact. It relies on average temperatures while ignoring the high\/low divergence, fails to contextualize the urban heat island effect despite briefly mentioning it, and leans heavily on emotive language rather than objective data analysis. If this is the best journalism Axios can muster, one must seriously question their editorial standards and scientific literacy. They\u2019re not informing the public \u2014 they\u2019re selling a narrative, one misleading map at a time.<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

In their recent article,\u00a0\u201cAmerica\u2019s summers keep getting warmer,\u201d\u00a0Axios claims that hotter summers across the U.S. are \u201cone of the clearest ways we experience climate change.\u201d That statement is misleading. The article focuses exclusively on \u201caverage summer temperatures\u201d while ignoring crucial underlying details \u2014 specifically, the difference between daytime highs and nighttime lows. <\/p>\n","protected":false},"author":121246920,"featured_media":332278,"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_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},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[691835626,691828304,691818056,691835624,691820545,691818087,691821016,691835625,691821374],"class_list":{"0":"post-381613","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","8":"tag-average-summer-temperatures","9":"tag-axios","10":"tag-climate-change","11":"tag-daytime-highs","12":"tag-dr-roy-spencer","13":"tag-global-warming","14":"tag-national-oceanic-and-atmospheric-administration-noaa","15":"tag-nighttime-lows","16":"tag-urban-heat-island-uhi-effect","18":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0Urban-Heat-Island-Effect-A162104504.jpg?fit=1880%2C1000&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-1Bh3","jetpack-related-posts":[{"id":216997,"url":"https:\/\/climatescience.press\/?p=216997","url_meta":{"origin":381613,"position":0},"title":"The Summer of 2022","author":"uwe.roland.gross","date":"09\/02\/2022","format":false,"excerpt":"We have always had hot and dry summers from time to time in Britain. There is no evidence whatsoever summers are getting hotter or drier.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/09\/image-131.png?fit=1024%2C401&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/09\/image-131.png?fit=1024%2C401&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/09\/image-131.png?fit=1024%2C401&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/09\/image-131.png?fit=1024%2C401&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":430724,"url":"https:\/\/climatescience.press\/?p=430724","url_meta":{"origin":381613,"position":1},"title":"New Temperature Study in Reno Finds Strong Urban Heat Island Bias at Official Climate Station","author":"uwe.roland.gross","date":"03\/12\/2026","format":false,"excerpt":"Independent reference system shows airport station reporting temperatures up to 3\u00b0F warmer than nearby properly sited station. 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A major criticism that Tallbloke has is the fact that most UK stations do not meet the World Meteorological Organization (WMO) criteria for a\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\/2025\/12\/AQMvwbZLv0Fvu4wQd6BJOz1-6pvtNTIclRcFcq17Eu-t3An1T6dOaKY5Q4HNGAG-xEl0_sdWJZdv1mw06aMzCp38IBjR2pJtRroygZLj3lIRufLf_v652nUjJ8f7lsyv_qHQpEF-iOgZPocBQdXF2q6HhLmX.jpeg?fit=1200%2C1200&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/AQMvwbZLv0Fvu4wQd6BJOz1-6pvtNTIclRcFcq17Eu-t3An1T6dOaKY5Q4HNGAG-xEl0_sdWJZdv1mw06aMzCp38IBjR2pJtRroygZLj3lIRufLf_v652nUjJ8f7lsyv_qHQpEF-iOgZPocBQdXF2q6HhLmX.jpeg?fit=1200%2C1200&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/AQMvwbZLv0Fvu4wQd6BJOz1-6pvtNTIclRcFcq17Eu-t3An1T6dOaKY5Q4HNGAG-xEl0_sdWJZdv1mw06aMzCp38IBjR2pJtRroygZLj3lIRufLf_v652nUjJ8f7lsyv_qHQpEF-iOgZPocBQdXF2q6HhLmX.jpeg?fit=1200%2C1200&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/AQMvwbZLv0Fvu4wQd6BJOz1-6pvtNTIclRcFcq17Eu-t3An1T6dOaKY5Q4HNGAG-xEl0_sdWJZdv1mw06aMzCp38IBjR2pJtRroygZLj3lIRufLf_v652nUjJ8f7lsyv_qHQpEF-iOgZPocBQdXF2q6HhLmX.jpeg?fit=1200%2C1200&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/AQMvwbZLv0Fvu4wQd6BJOz1-6pvtNTIclRcFcq17Eu-t3An1T6dOaKY5Q4HNGAG-xEl0_sdWJZdv1mw06aMzCp38IBjR2pJtRroygZLj3lIRufLf_v652nUjJ8f7lsyv_qHQpEF-iOgZPocBQdXF2q6HhLmX.jpeg?fit=1200%2C1200&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":230031,"url":"https:\/\/climatescience.press\/?p=230031","url_meta":{"origin":381613,"position":3},"title":"Canadian Summer Urban Heat Island Effects: Some Results in Alberta","author":"uwe.roland.gross","date":"11\/19\/2022","format":false,"excerpt":"Calgary leads the list of Canadian cities with increased urbanization, with an estimated 50% of the nighttime warming trends across 10 Canadian mostly-metro areas attributable to increased urbanization, and 20% of the daytime warming trends.","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-662.png?fit=1200%2C648&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-662.png?fit=1200%2C648&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-662.png?fit=1200%2C648&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-662.png?fit=1200%2C648&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/11\/image-662.png?fit=1200%2C648&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":416380,"url":"https:\/\/climatescience.press\/?p=416380","url_meta":{"origin":381613,"position":4},"title":"Canada Summer Daily Low Temperature Trends, 1900-2023","author":"uwe.roland.gross","date":"12\/06\/2025","format":false,"excerpt":"This is the Tmin (daily minimum temperature) version of the Canada temperature trend results I posted yesterday, which were for Tmax (daily maximum temperatures). These results are quite different: whereas the high temperatures have seen essentially no warming trends across southern Canada since 1900, the nighttime temperatures have warmed in\u2026","rel":"","context":"In \"6 provinces\"","block_context":{"text":"6 provinces","link":"https:\/\/climatescience.press\/?tag=6-provinces"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/0AQPLqX6NSrUpNd4NZG8zNpbW-ANDphPlOykD8Jls4SykfF2WArofRG5qc3b9qPEIuplFfpbq-6YKP_lVKnLyi0z-hywO1Y3eceMSxDFK43hgBz6pqdiZKXWc9EHTh01j.jpeg?fit=1149%2C939&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/0AQPLqX6NSrUpNd4NZG8zNpbW-ANDphPlOykD8Jls4SykfF2WArofRG5qc3b9qPEIuplFfpbq-6YKP_lVKnLyi0z-hywO1Y3eceMSxDFK43hgBz6pqdiZKXWc9EHTh01j.jpeg?fit=1149%2C939&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/0AQPLqX6NSrUpNd4NZG8zNpbW-ANDphPlOykD8Jls4SykfF2WArofRG5qc3b9qPEIuplFfpbq-6YKP_lVKnLyi0z-hywO1Y3eceMSxDFK43hgBz6pqdiZKXWc9EHTh01j.jpeg?fit=1149%2C939&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/0AQPLqX6NSrUpNd4NZG8zNpbW-ANDphPlOykD8Jls4SykfF2WArofRG5qc3b9qPEIuplFfpbq-6YKP_lVKnLyi0z-hywO1Y3eceMSxDFK43hgBz6pqdiZKXWc9EHTh01j.jpeg?fit=1149%2C939&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/12\/0AQPLqX6NSrUpNd4NZG8zNpbW-ANDphPlOykD8Jls4SykfF2WArofRG5qc3b9qPEIuplFfpbq-6YKP_lVKnLyi0z-hywO1Y3eceMSxDFK43hgBz6pqdiZKXWc9EHTh01j.jpeg?fit=1149%2C939&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":216584,"url":"https:\/\/climatescience.press\/?p=216584","url_meta":{"origin":381613,"position":5},"title":"Agricultural Heat Islands","author":"uwe.roland.gross","date":"08\/31\/2022","format":false,"excerpt":"US summer afternoon temperatures have not increased over the last 60 years, but nighttime temperatures have.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/08\/image-1451.png?fit=816%2C581&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/08\/image-1451.png?fit=816%2C581&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/08\/image-1451.png?fit=816%2C581&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/08\/image-1451.png?fit=816%2C581&ssl=1&resize=700%2C400 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/381613","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=381613"}],"version-history":[{"count":5,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/381613\/revisions"}],"predecessor-version":[{"id":381621,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/381613\/revisions\/381621"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/media\/332278"}],"wp:attachment":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=381613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=381613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=381613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}