Emergence of strong trends in humid heat intensity and duration in recent decades over South Asia

Emergence of strong trends in humid heat intensity and duration in recent decades over South Asia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Emergence of strong trends in humid heat intensity and duration in recent decades over South Asia Jitendra Singh, Deepti Singh, Sebastian Sippel, Erich Fischer This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4756159/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract South Asia’s climate features the hottest temperatures in the pre-monsoon season followed by intense humid heat after the onset of the summer monsoons. Here, we examine trends and drivers of humid heat extremes during the monsoon and pre-monsoon season Since the early 2000s, humid heat extremes in the monsoon season have warmed two times faster than the rate observed since the 1950s. In addition, the average duration of monsoon season humid heat extremes has increased from ~2 days in the 1950s to several weeks in the recent decades across South Asia, a region with high population density. The intensification of humid heat extremes is driven in part by peak humidity in the monsoon season occurring nearly two weeks earlier since 2000 compared to the mid-20th century baseline. and coinciding with higher temperatures. Humid heat extremes during the pre-monsoon season are also increasing across most of the region. The exception is Western South Asia, the hottest and driest region, that experienced remarkably strong cooling trends during the pre-monsoon since the 2000s. We find that rising precipitation-induced humidity levels explain the intensifying trends in humid heat extremes in the monsoon season, while declining humidity levels drive the decreasing trends in the pre-monsoon season. Our findings emphasize the need for policies and adaptations and mitigation measures to align with the substantial escalation in humid heat intensity and duration that threatens public health, labor productivity, and the economy. Earth and environmental sciences/Climate sciences/Climate change Earth and environmental sciences/Environmental sciences Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SuppInfoSouthAsiaHeatExtremeFinal.pdf Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4756159","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":332026898,"identity":"bdbacb01-edd8-4a13-973c-602ff24ef865","order_by":0,"name":"Jitendra Singh","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0001-9132-0269","institution":"ETH Zurich","correspondingAuthor":true,"prefix":"","firstName":"Jitendra","middleName":"","lastName":"Singh","suffix":""},{"id":332026899,"identity":"64b32f80-5206-4c70-a7de-573f244fab91","order_by":1,"name":"Deepti Singh","email":"","orcid":"https://orcid.org/0000-0001-6568-435X","institution":"Washington State University, Vancouver","correspondingAuthor":false,"prefix":"","firstName":"Deepti","middleName":"","lastName":"Singh","suffix":""},{"id":332026900,"identity":"9b19cced-3e05-47e2-b7ea-52938deae59f","order_by":2,"name":"Sebastian Sippel","email":"","orcid":"https://orcid.org/0000-0002-4510-4458","institution":"Leipzig University","correspondingAuthor":false,"prefix":"","firstName":"Sebastian","middleName":"","lastName":"Sippel","suffix":""},{"id":332026901,"identity":"d2dda43e-a829-4b11-b911-31fc3338e9b9","order_by":3,"name":"Erich Fischer","email":"","orcid":"https://orcid.org/0000-0003-1931-6737","institution":"ETH Zurich","correspondingAuthor":false,"prefix":"","firstName":"Erich","middleName":"","lastName":"Fischer","suffix":""}],"badges":[],"createdAt":"2024-07-17 12:15:48","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-4756159/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4756159/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":66311338,"identity":"5a8c4c72-1f3e-489c-90a5-f4daece8936b","added_by":"auto","created_at":"2024-10-10 08:48:54","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1790985,"visible":true,"origin":"","legend":"","description":"","filename":"SouthAsiaHeatExtremeFinal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4756159/v1_covered_35d8c3d6-1640-4bdf-bea7-f35b8edebc77.pdf"},{"id":61271301,"identity":"59140c63-516a-45fd-976f-e95a34606930","added_by":"auto","created_at":"2024-07-29 02:14:49","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":13016051,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"SuppInfoSouthAsiaHeatExtremeFinal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4756159/v1/7894336f990d14a4c8aa39bd.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Emergence of strong trends in humid heat intensity and duration in recent decades over South Asia","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-4756159/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4756159/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"South Asia’s climate features the hottest temperatures in the pre-monsoon season followed by intense humid heat after the onset of the summer monsoons. Here, we examine trends and drivers of humid heat extremes during the monsoon and pre-monsoon season Since the early 2000s, humid heat extremes in the monsoon season have warmed two times faster than the rate observed since the 1950s. In addition, the average duration of monsoon season humid heat extremes has increased from ~2 days in the 1950s to several weeks in the recent decades across South Asia, a region with high population density. The intensification of humid heat extremes is driven in part by peak humidity in the monsoon season occurring nearly two weeks earlier since 2000 compared to the mid-20th century baseline. and coinciding with higher temperatures. Humid heat extremes during the pre-monsoon season are also increasing across most of the region. The exception is Western South Asia, the hottest and driest region, that experienced remarkably strong cooling trends during the pre-monsoon since the 2000s. We find that rising precipitation-induced humidity levels explain the intensifying trends in humid heat extremes in the monsoon season, while declining humidity levels drive the decreasing trends in the pre-monsoon season. Our findings emphasize the need for policies and adaptations and mitigation measures to align with the substantial escalation in humid heat intensity and duration that threatens public health, labor productivity, and the economy.","manuscriptTitle":"Emergence of strong trends in humid heat intensity and duration in recent decades over South Asia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-29 02:14:44","doi":"10.21203/rs.3.rs-4756159/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"319ad14c-be47-4df5-8110-0480f30ba25b","owner":[],"postedDate":"July 29th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":35155830,"name":"Earth and environmental sciences/Climate sciences/Climate change"},{"id":35155831,"name":"Earth and environmental sciences/Environmental sciences"}],"tags":[],"updatedAt":"2024-10-10T08:40:46+00:00","versionOfRecord":[],"versionCreatedAt":"2024-07-29 02:14:44","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4756159","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4756159","identity":"rs-4756159","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}