Theoretical and Applied Climatology

, Volume 131, Issue 1–2, pp 733–743 | Cite as

Differences between true mean temperatures and means calculated with four different approaches: a case study from three Croatian stations

  • Ognjen Bonacci
  • Ivana ŽeljkovićEmail author
Original Paper


Different countries use varied methods for daily mean temperature calculation. None of them assesses precisely the true daily mean temperature, which is defined as the integral of continuous temperature measurements in a day. Of special scientific as well as practical importance is to find out how temperatures calculated by different methods and approaches deviate from the true daily mean temperature. Five mean daily temperatures were calculated (T0, T1, T2, T3, T4) using five different equations. The mean of 24-h temperature observations during the calendar day is accepted to represent the true, daily mean T0. The differences Δi between T0 and four other mean daily temperatures T1, T2, T3, and T4 were calculated and analysed. In the paper, analyses were done with hourly data measured in a period from 1 January 1999 to 31 December 2014 (149,016 h, 192 months and 16 years) at three Croatian meteorological stations. The stations are situated in distinct climatological areas: Zagreb Grič in a mild climate, Zavižan in the cold mountain region and Dubrovnik in the hot Mediterranean. Influence of fog on the temperature is analysed. Special attention is given to analyses of extreme (maximum and minimum) daily differences occurred at three analysed stations. Selection of the fixed local hours, which is in use for calculation of mean daily temperature, plays a crucial role in diminishing of bias from the true daily temperature.



The authors gratefully appreciate the anonymous reviewers for their careful reading of our paper and constructive comments, which helped us to improve the manuscript.


  1. Barg M (1976) Zur Berechnung von Tagesmitteln aus Terminwerten. Z Meteorol 26:160–173Google Scholar
  2. Bonacci O (2012) Increase of mean annual surface air temperature in the Western Balkans during last 30 years. Vodoprivreda 44(255–257):75–89Google Scholar
  3. Bonacci O, Željković I, Šakić Trogrlić R, Milković J (2013) Differences between true mean daily, monthly, annual air temperatures and air temperatures calculated with three equations: a case study from three Croatian stations. Theor Appl Climat 114:271–279CrossRefGoogle Scholar
  4. Bonacci O, Trninić D, Roje-Bonacci T (2008) Analysis of the water temperature regime of the Danube and its tributaries in Croatia. Hydrol Proc 22(7):1014–1021CrossRefGoogle Scholar
  5. Brooks CEP (1921) True mean temperature. Mon Weather Rev 49:226–229CrossRefGoogle Scholar
  6. Collison P, Tabony RC (1984) The estimation on mean temperatures from daily maxima and minima. Meteorol Mag 113:329–337Google Scholar
  7. Conner G, Foster S (2008) Searching for the daily mean temperature. Extended Abstracts, Paper 4.3, 17th Conference on Applied Climatology, 88th Annual Meeting American Meteorological Society, 12 August 2008, Whistler British Columbia, CanadaGoogle Scholar
  8. Conner G, Foster S (2010) Daily mean temperature formulas. Extended Abstracts, Paper 6.6, 18th Conference on Applied Climatology, 90th Annual Meeting American Meteorological Society, 19 January 2010, Atlanta GA, USAGoogle Scholar
  9. Dewey C (1857) On the best hours of daily observations to find the mean temperature for the year. Eleventh Annual Report of the Smithsonian Institution. Smithsonian Institution, WashingtonGoogle Scholar
  10. Drew J (1860) Practical meteorology, 2nd edn. John van Voorst, London, p. 68Google Scholar
  11. Garbrecht J, Fernandez GP (1994) Visualization of trends and fluctuations in climatic records. Water Res Bul 30(2):297–306CrossRefGoogle Scholar
  12. Glickman TS (ed) (2000) Glossary of meteorology. American Meteorological Society, BostonGoogle Scholar
  13. Gough WA, He D (2015) Diurnal temperature asymmetries and fog at Churchill, Manitoba. Theor Appl Climat 121:113–119CrossRefGoogle Scholar
  14. Harris SA, Pedersen JH (1995) Comparison of three methods of calculating air temperature from electronic measurements. Z Geomorph 39(2):203–210Google Scholar
  15. Hartzell FZ (1919) Comparison of methods for computing daily mean temperatures: effect of discrepancies upon investigations of climatologists and biologists. Mon Weather Rev 47(11):799–801CrossRefGoogle Scholar
  16. Heino R (1994) Climate in Finland during the period of meteorological observations. Finnish Meteorological Institute Contributions 12, Helsinki, p 209Google Scholar
  17. IPCC (1990) Climate change: the IPCC scientific assessment. Cambridge University Press, CambridgeGoogle Scholar
  18. Jones PD, Moberg A (2003) Hemispheric and large-scale surface air temperature variations: an extensive revision and an update to 2001. J Clim 16:206–223CrossRefGoogle Scholar
  19. Kaufmann RK, Gopal S, Tang X, Raciti SM, Lyons PE, Geron N, Craig F (2013) Revisiting the weather effect on energy consumption: implications for the impact of climate change. Energy Policy 62:1377–1384CrossRefGoogle Scholar
  20. Li Z, Wang K, Zhoua C, Wang L (2015) Modelling the true monthly mean temperature from continuous measurements over global land. Int J Climatol. doi: 10.1002/joc.4445 Google Scholar
  21. Malcolm IA, Soulsby C, Hannah DM, Bacon PJ, Youngson AF, Tetzlaff D (2008) The influence of riparian woodland on stream temperatures: implications for the performance of juvenile salmonids. Hydrol Proc 22(7):968–979CrossRefGoogle Scholar
  22. MATLAB and Statistics Toolbox Release (2011) The MathWorks, Inc., Natick, Massachusetts, United StatesGoogle Scholar
  23. McAdie A (1891) Mean temperatures and their corrections. Signal Office, War Department, WashingtonGoogle Scholar
  24. NOAA (National Oceanic and Atmospheric Administration U. S.) (1997) World Weather Records Vols. 1–6Google Scholar
  25. Olesen JE, Bindi M (2002) Consequences of climate change for European agriculture productivity, land use and policy. Europ J Agr 16(4):239–262CrossRefGoogle Scholar
  26. Peel MC, Finlayson BL, McMahon TA (2007) Updated world map of the Köppen-Geiger climate classification. Hydrol Earth Syst Sci 11:1633–1644CrossRefGoogle Scholar
  27. Piani C, Weedon G, Best M, Gomes S, Viterbo P, Hagemann S, Haerter J (2010) Statistical bias correction of global simulated daily precipitation and temperature for the application of hydrological models. J Hydrol 395:199–215CrossRefGoogle Scholar
  28. Reicosky DC, Winkelman LJ, Baker JM, Baker DG (1989) Accuracy of hourly air temperatures calculated from daily minima and maxima. Agric For Meteorol 46:193–209CrossRefGoogle Scholar
  29. Rosenzweig C, Parry ML (1994) Potential impact of climate change on world food supply. Nature 367:133–138CrossRefGoogle Scholar
  30. Sakellariou NK, Kambezidis HD (2015) Improving the estimation of the true mean monthly and true mean annual air temperatures in Greece. Atmos Sci Let ( 6 pp. DOI: 10.1002/asl.592
  31. Smith A, Lott N, Vose R (2011) The integrated surface database: recent developments and partnerships. Bullet Amer Meteorol Soc 92(6):704–708. doi: 10.1175/2011BAMS3015.1 CrossRefGoogle Scholar
  32. Trewin B (2004) Effects of changes in algorithms used for calculation of Australian mean temperature. Aust Meteorol Mag 53:1–11Google Scholar
  33. Weber RO (1993) Influence of different daily mean formulas on monthly and annual averages of temperature. Theor Appl Climat 47(4):205–213CrossRefGoogle Scholar
  34. Weiss A, Hays CJ (2005) Calculating daily mean air temperatures by different methods: implication from a non-linear algorithm. Agr For Meteorol 126(1–2):57–65CrossRefGoogle Scholar
  35. WMO (World Meteorological Organization) (1983) Guide to climatological practices. WMO, Geneva, WMO No. 100Google Scholar
  36. Zeng X, Wang A (2012) What is monthly mean land surface air temperature? EOS Trans AGU 93(15):156–157CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Wien 2016

Authors and Affiliations

  1. 1.Faculty of Civil Engineering, Architecture and GeodesyUniversity of SplitSplitCroatia
  2. 2.SplitCroatia

Personalised recommendations