Climatic Change

, Volume 118, Issue 3–4, pp 811–825 | Cite as

Heat waves in the United States: definitions, patterns and trends

  • Tiffany T. SmithEmail author
  • Benjamin F. Zaitchik
  • Julia M. Gohlke


High temperatures and heat waves are related but not synonymous concepts. Heat waves, generally understood to be acute periods of extreme warmth, are relevant to a wide range of stakeholders because of the impacts that these events have on human health and activities and on natural environments. Perhaps because of the diversity of communities engaged in heat wave monitoring and research, there is no single, standard definition of a heat wave. Experts differ in which threshold values (absolute versus relative), duration and ancillary variables to incorporate into heat wave definitions. While there is value in this diversity of perspectives, the lack of a unified index can cause confusion when discussing patterns, trends, and impacts. Here, we use data from the North American Land Data Assimilation System to examine patterns and trends in 15 previously published heat wave indices for the period 1979–2011 across the Continental United States. Over this period the Southeast region saw the highest number of heat wave days for the majority of indices considered. Positive trends (increases in number of heat wave days per year) were greatest in the Southeast and Great Plains regions, where more than 12 % of the land area experienced significant increases in the number of heat wave days per year for the majority of heat wave indices. Significant negative trends were relatively rare, but were found in portions of the Southwest, Northwest, and Great Plains.


Heat Wave Conus Region Heat Index National Weather Service Heat Wave Event 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The National Institute of Environmental Health Sciences Grant R21 ES020205 supported this study. The authors would like to thank Seth Guikema for advice on the appropriate statistical methods to use for this study.


  1. Alexander LV, Zhang X, Peterson TC, Caesar J, Gleason B, Tank A, Haylock M, Collins D, Trewin B, Rahimzadeh F, Tagipour A, Kumar KR, Revadekar J, Griffiths G, Vincent L, Stephenson DB, Burn J, Aguilar E, Brunet M, Taylor M, New M, Zhai P, Rusticucci M, Vazquez-Aguirre JL (2006) Global observed changes in daily climate extremes of temperature and precipitation. J Geophys Res-Atmos 111:22CrossRefGoogle Scholar
  2. Anderson BG, Bell ML (2009) Weather-related mortality how heat, cold, and heat waves affect mortality in the United States. Epidemiology 20:205–213CrossRefGoogle Scholar
  3. Anderson GB, Bell ML (2011) Heat waves in the United States: mortality risk during heat waves and effect modification by heat wave characteristics in 43 U.S. Communities. Environ Heal Perspect 119:210–218CrossRefGoogle Scholar
  4. Barnett AG, Tong S, Clements ACA (2010) What measure of temperature is the best predictor of mortality? Environ Res 110:604–611CrossRefGoogle Scholar
  5. Cosgrove BA, Lohmann D, Mitchell KE, Houser PR, Wood EF, Schaake JC, Robock A, Marshall C, Sheffield J, Duan QY, Luo LF, Higgins RW, Pinker RT, Tarpley JD, Meng J (2003) Real-time and retrospective forcing in the North American Land Data Assimilation System (NLDAS) project. J Geophys Res-Atmos 108:12Google Scholar
  6. Curriero FC, Heiner KS, Samet JM, Zeger SL, Strug L, Patz JA (2002) Temperature and mortality in 11 cities of the eastern United States. Am J Epidemiol 155:80–87CrossRefGoogle Scholar
  7. Davis RE, Knight D, Hondula D, Knappenberger PC (2006) A comparison of biometeorological comfort indices and human mortality during heat waves in the United States. Paper presented at Human biometeorology: The heat 17th conference on biometeorology and aerobiology, San Diego, CA. Retrieved from
  8. Efthymiadis D, Goodess CM, Jones PD (2011) Trends in Mediterranean gridded temperature extremes and large-scale circulation influences. Nat Hazard Earth Syst Sci 11:2199–2214CrossRefGoogle Scholar
  9. El Kenawy A, Lopez-Moreno JI, Vicente-Serrano SM (2011) Recent trends in daily temperature extremes over northeastern Spain (1960–2006). Nat Hazard Earth Syst Sci 11:2583–2603CrossRefGoogle Scholar
  10. Global Climate Change Impacts in the United States, Thomas R. Karl, Jerry M. Melillo, and Thomas C. Peterson, (eds.). Cambridge University Press, 2009Google Scholar
  11. Grundstein AJ, Ramseyer C, Zhao F, Pesses JL, Akers P, Qureshi A, Becker L, Knox JA, Petro M (2012) A retrospective analysis of American football hyperthermia deaths in the United States. Int J Biometeorol 56:11–20CrossRefGoogle Scholar
  12. Hajat S, Armstrong B, Baccini M, Biggeri A, Bisanti L, Russo A, Paldy A, Menne B, Kosatsky T (2006) Impact of high temperatures on mortality - Is there an added heat wave effect? Epidemiology 17:632–638CrossRefGoogle Scholar
  13. Hansen J, Sato M, Ruedy R (2012) Perception of climate change. Proc Natl Acad Sci U S A 109:E2415–E2423CrossRefGoogle Scholar
  14. IPCC (2007) Climate Change 2007: the physical science basis. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 ppGoogle Scholar
  15. IPCC (2012) Managing the risks of extreme events and disasters to advance climate change adaptation. In: Field CB, Barros V, Stocker TF, Qin D, Dokken DJ, Ebi KL, Mastrandrea MD, Mach KJ, Plattner G-K, Allen SK, Tignor M, Midgley PM (eds) A special report of Working Groups I and II of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK, and New York, NY, USA, 582 ppGoogle Scholar
  16. Kuglitsch FG, Toreti A, Xoplaki E, Della-Marta PM, Zerefos CS, Turkes M, Luterbacher J (2010) Heat wave changes in the eastern Mediterranean since 1960. Geophys Res Lett 37:5CrossRefGoogle Scholar
  17. Luo LF, Robock A, Mitchell KE, Houser PR, Wood EF, Schaake JC, Lohmann D, Cosgrove B, Wen FH, Sheffield J, Duan QY, Higgins RW, Pinker RT, Tarpley JD (2003) Validation of the North American Land Data Assimilation System (NLDAS) retrospective forcing over the southern Great Plains. J Geophys Res-Atmos 108:10Google Scholar
  18. Medina-Ramon M, Schwartz J (2007) Temperature, temperature extremes, and mortality: a study of acclimatisation and effect modification in 50 US cities. Occupational and Environmental Medicine 64:827–833CrossRefGoogle Scholar
  19. Meehl GA, Tebaldi C (2004) More intense, more frequent, and longer lasting heat waves in the 21st century. Science 305:994–997CrossRefGoogle Scholar
  20. Mesinger F, DiMego G, Kalnay E, Mitchell K, Shafran PC, Ebisuzaki W, Jovic D, Woollen J, Rogers E, Berbery EH, Ek MB, Fan Y, Grumbine R, Higgins W, Li H, Lin Y, Manikin G, Parrish D, Shi W (2006) North American regional reanalysis. Bulletin of the American Meteorological Society 87:343–360CrossRefGoogle Scholar
  21. Metzger KB, Ito K, Matte TD (2010) Summer Heat and Mortality in New York City: How Hot Is Too Hot? Environ Heal Perspect 118:80–86Google Scholar
  22. Mitchell KE, Lohmann D, Houser PR, Wood EF, Schaake JC, Robock A, Cosgrove BA, Sheffield J, Duan QY, Luo LF, Higgins RW, Pinker RT, Tarpley JD, Lettenmaier DP, Marshall CH, Entin JK, Pan M, Shi W, Koren V, Meng J, Ramsay BH, Bailey AA (2004) The multi-institution North American Land Data Assimilation System (NLDAS): Utilizing multiple GCIP products and partners in a continental distributed hydrological modeling system. J Geophys Res-Atmos 109:32Google Scholar
  23. Moberg A, Jones PD, Lister D, Walther A, Brunet M, Jacobeit J, Alexander LV, Della-Marta PM, Luterbacher J, Yiou P, Chen DL, Tank A, Saladie O, Sigro J, Aguilar E, Alexandersson H, Almarza C, Auer I, Barriendos M, Begert M, Bergstrom H, Bohm R, Butler CJ, Caesar J, Drebs A, Founda D, Gerstengarbe FW, Micela G, Maugeri M, Osterle H, Pandzic K, Petrakis M, Srnec L, Tolasz R, Tuomenvirta H, Werner PC, Linderholm H, Philipp A, Wanner H, Xoplaki E (2006) Indices for daily temperature and precipitation extremes in Europe analyzed for the period 1901-2000. J Geophys Res-Atmos 111:25CrossRefGoogle Scholar
  24. Pan ZT, Arritt RW, Takle ES, Gutowski WJ, Anderson CJ, Segal M (2004) Altered hydrologic feedback in a warming climate introduces a ''warming hole''. Geophys Res Lett 31:4CrossRefGoogle Scholar
  25. Peng RD, Bobb JF, Tebaldi C, McDaniel L, Bell ML, Dominici F (2011) Toward a quantitative estimate of future heat wave mortality under global climate change. Environ Heal Perspect 119:701–706CrossRefGoogle Scholar
  26. Robinson PJ (2001) On the definition of a heat wave. J Appl Meteorol 40:762–775CrossRefGoogle Scholar
  27. Rothfusz LP, Scientific Services Division (1990) The heat index "equation" (or, more than you ever wanted to know about heat index) (SR 90-23). Retrieved from NWS Southern Region Headquarters website:
  28. Schar C, Vidale PL, Luthi D, Frei C, Haberli C, Liniger MA, Appenzeller C (2004) The role of increasing temperature variability in European summer heatwaves. Nature 427:332–336CrossRefGoogle Scholar
  29. Semenza JC, McCullough JE, Flanders WD, McGeehin MA, Lumpkin JR (1999) Excess hospital admissions during the July 1995 heat wave in Chicago. American Journal of Preventive Medicine 16:269–277CrossRefGoogle Scholar
  30. Steadman RG (1979) Assessment of sultriness.2. Effects of wind, extra radiation and barometric pressure on apparent temperature. J Appl Meteorol 18:874–885CrossRefGoogle Scholar
  31. Steadman RG (1984) A universal scale of apparent temperature. J Clim Appl Meteorol 23:1674–1687CrossRefGoogle Scholar
  32. Tan JG, Zheng YF, Song GX, Kalkstein LS, Kalkstein AJ, Tang X (2007) Heat wave impacts on mortality in Shanghai, 1998 and 2003. Int J Biometeorol 51:193–200CrossRefGoogle Scholar
  33. Trenberth KE, Jones PD, Ambenje P, Bojariu R, Easterling D, Klein Tank A, Parker D, Rahimzadeh F, Renwick JA, Rusticucci M, Soden B, Zhai P (2007) Observations: surface and atmospheric climate change. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate Change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK, pp 237–336Google Scholar
  34. Williams S, Nitschke M, Sullivan T, Tucker GR, Weinstein P, Pisaniello DL, Parton KA, Bi P (2012) Heat and health in Adelaide, South Australia: assessment of heat thresholds and temperature relationships. Sci Total Environ 414:126–133CrossRefGoogle Scholar
  35. Xia YL, Mitchell K, Ek M, Sheffield J, Cosgrove B, Wood E, Luo LF, Alonge C, Wei HL, Meng J, Livneh B, Lettenmaier D, Koren V, Duan QY, Mo K, Fan Y, Mocko D (2012) Continental-scale water and energy flux analysis and validation for the North American Land Data Assimilation System project phase 2 (NLDAS-2): 1. Intercomparison and application of model products. Journal of Geophysical Research-Atmospheres 117:27Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • Tiffany T. Smith
    • 1
    Email author
  • Benjamin F. Zaitchik
    • 1
  • Julia M. Gohlke
    • 2
  1. 1.Department of Earth and Planetary SciencesJohns Hopkins UniversityBaltimoreUSA
  2. 2.Department of Environmental Health SciencesUniversity of Alabama at BirminghamBirminghamUSA

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