Abstract
Precipitation and temperature variability and change across Africa significantly impact the continent’s key socio-economic sectors such as agriculture, water resources, health and infrastructure development. Despite experiencing the highest warming in the past decades, Africa’s most recent climate normals are yet to be documented. This study presents the latest climate normals, 1991–2020, as defined by the World Meteorological Organization (WMO) for key variables: precipitation, temperature (mean, minimum and maximum), and potential evaporation (PET). Analysing monthly observational data from the Climatic Research Unit (CRU) version 4.07, we examine the spatio-temporal variability of these variables over Africa and its nine climate sub-regions during 1991–2020, and changes relative to the baseline climate normals (1961–1990) and previous normal periods (1971–2000 and 1981–2010). We employ anomaly and trend analysis to investigate changes during the different periods, while empirical orthogonal function (EOF) is used to identify dominant seasonal patterns. Distinct precipitation characteristics emerge across the sub-regions, with the Mediterranean (MED) and Madagascar (MDG) exhibiting a consistent decreasing trend since 1961–1990, while other regions experience an increase compared to the last normal period (1981–2010). The Sahara (SAH), Western Africa (WAF), and Northern Eastern Africa (NEAF) show higher precipitation during 1991–2020 than in 1961–1990. Mean temperature shows an overall increase across Africa, with MED, SAH and Eastern Southern Africa (ESAF) recording the highest temperature rise of 0.79, 1.71 and 0.68 °C, respectively, compared to 1961–1990. Similar trends are reflected in minimum and maximum temperatures. PET patterns align closely with temperature changes, particularly in SAH, where PET increases by 35.7 mm during the last climate normals compared to 1961–1990. The EOF results agree with the climatological means. However, a decrease in the percentage variance of the dominant modes across the periods for temperature and PET suggests possible shifts in climate oscillations or dynamics. This study contributes vital insights into observed and expected climate trends over Africa, benefiting the scientific community, stakeholders, and end-users. The results emphasise the urgency of climate adaptation measures in Africa and underscore the necessity for proactive strategies to address climate change impacts.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Data availability
The CRU data that support the findings of this study are openly available at https://crudata.uea.ac.uk/cru/data/hrg/cru_ts_4.07/cruts.2304141047.v4.07/. All the analyses are performed using MATLAB.
References
Akinsanola AA, Ogunjobi KO, Ajayi VO, Adefisan EA, Omotosho JA, Sanogo S (2017) Comparison of five gridded precipitation products at climatological scales over West Africa. Meteorol Atmos Phys 129(6):669–689. https://doi.org/10.1007/s00703-016-0493-6
Arguez A, Vose RS (2011) The definition of the standard WMO climate normal: the key to deriving alternative climate normals. Bull Am Meteorol Soc 92(6):699–704. https://doi.org/10.1175/2010BAMS2955.1
Assamnew AD, Tsidu MG (2023) Assessing improvement in the fifth-generation ECMWF atmospheric reanalysis precipitation over East Africa. Int J Climatol 43(1):17–37. https://doi.org/10.1002/joc.7697
Biasutti M (2019) Rainfall trends in the African sahel: characteristics, processes, and causes. WIREs Clim Change 10:e591. https://doi.org/10.1002/wcc.591
Ceccherini G, Russo S, Ameztoy I, Francesco Marchese A, Carmona-Moreno C (2017) Heat waves in Africa 1981–2015, observations and reanalysis. Nat Hazards Earth Syst Sci 17(1):115–125. https://doi.org/10.5194/nhess-17-115-2017
Dinku T, Connor SJ, Ceccato P, F. R (2008) Comparison of global gridded precipitation products over a mountainous region of Africa. Int J Climatol 28(12):1627–1638. https://doi.org/10.1002/joc.1669
Dinku T, Faniriantsoa R, Islam S, Nsengiyumva G, Grossi A (2022) The Climate Data Tool: enhancing Climate services Across Africa. Front Clim 3:787519. https://doi.org/10.3389/fclim.2021.787519
Griffiths JF (1972) Climates of Africa. World Survey of Climatology. Elsevier, Amsterdam, p 602
Harris I, Osborn TJ, Jones P, Lister D (2020) Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. Sci Data 7:109. https://doi.org/10.1038/s41597-020-0453-3
Huebner L, Al-Quraishi AMF, Branch O, Gaznayee HAA (2022) Sahel Afforestation and simulated risks of heatwaves and flooding Versus Ecological Revegetation that combines planting and succession. J Geosci Environ Prot 10(2):94–108. https://doi.org/10.4236/gep.2022.102007
Hulme M (1992) Rainfall changes in Africa: 1931–1960 to 1961–1990. Int J Climatol 12:685–699. https://doi.org/10.1002/joc.3370120703
Ilori OW, Ajayi VO (2020) Change detection and Trend Analysis of Future temperature and rainfall over West Africa. Earth Syst Environ 4(3):493–512. https://doi.org/10.1007/s41748-020-00174-6
IPCC (2021) Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2391 pp. https://doi.org/10.1017/9781009157896
Iturbide M, Gutiérrez JM, Alves LM, Bedia J, Cerezo-Mota, Ruth, Cimadevilla E, Cofiño AS, Di Luca A, Faria SH, Gorodetskaya I, Hauser M, Herrera S, Hennessy K, Hewitt H, Jones R, Krakovska S, Manzanas R, Martínez-Castro D, Narisma GT, Nurhati I, Pinto I, van den Seneviratne SI, Vera CS (2020) An update of IPCC climate reference regions for subcontinental analysis of climate model data: definition and aggregated datasets. Earth Syst Sci Data 12:2959–2970. https://doi.org/10.5194/essd-12-2959-2020
Koné B, Diedhiou A, Touré NE, Sylla MB, Giorgi F, Anquetin S, Bamba A, Diawara A, Kobea AT (2018) Sensitivity study of the Regional Climate Model RegCM4 to different convective schemes over West Africa. Earth Syst Dyn 9(4):1261–1278. https://doi.org/10.5194/esd-9-1261-2018
Krakauer NY, Devineni N (2015) Up-to-date probabilistic temperature climatologies. Environ Res Lett 10(2):024014. https://doi.org/10.1088/1748-9326/10/2/024014
Leemans R, Cramer WP (1990) The IIASA Database for Mean Monthly Values of Temperature, Precipitation and Cloudiness on Global Terrestrial Grid, Working Paper No. WP-90.-41, Biosphere Dynamics Project, International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria 25 pp. http://www.iiasa.ac.at/Admin/PUB/Documents/RR-91-018.pdf
Legates DR, Willmott CJ (1990) Mean seasonal and spatial variability in gauge-corrected, global precipitation. Int J Climatol 10(2):111–127. https://doi.org/10.1002/joc.3370100202
Leroux M (1983) The Climate of Tropical Africa. Champion-Slatkine, Paris, p 650
Livezey RE, Vinnikov KY, Timofeyeva MM, van den Tinker R (2007) Estimation and extrapolation of Climate normals and climatic trends ROBERT. J Appl Meteorol Climatol 46(11):1759–1776. https://doi.org/10.1175/2007JAMC1666.1
Lorenz EN (1956) Empirical orthogonal functions and statistical weather prediction. Scientific report No. 1, statistical forecasting project. Massachusetts Institute of Technology, USA
Lüdecke H-J, Müller-Plath G, Wallace MG, Lüning S (2021) Decadal and multidecadal natural variability of African rainfall. J Hydrology: Reg Stud 34:100795. https://doi.org/10.1016/j.ejrh.2021.100795
Malhi Y, Adu-Bredu S, Asare RA, Lewis SL, Mayaux P (2013) African rainforests: past, present and future. Philos Trans R Soc B 368:20120312. https://doi.org/10.1098/rstb.2012.0312
Mumuni S, Aleer MJ (2023) Zero Hunger by 2030 – are we on track? Climate variability and change impacts on food security in Africa. Cogent Food Agric 9(1):2171830. https://doi.org/10.1080/23311932.2023.2171830
Nicholson SE (2000) The nature of rainfall variability over Africa on time scales of decades to millenia. Glob Planet Change 26:137–158
Nicholson SE, Fink AH, Funk C (2018) Assessing recovery and change in West Africa’s rainfall regime from a 161-year record. Int J Climatol 38:3770–3786. https://doi.org/10.1002/joc.5530
Nooni IK, Hagan DFT, Wang G, Ullah W, Lu J, Li S, Dzakpasu M, Prempeh NA, Lim Kam Sian KTC (2021) Future changes in simulated evapotranspiration across Continental Africa based on CMIP6 CNRM-CM6. Int J Environ Res Public Health 18(13):6760. https://doi.org/10.3390/ijerph18136760
OECD (2016) Agriculture in Sub-saharan Africa: prospects and challenges for the next decade. OECD-FAO Agricultural Outlook 2016–2025. OECD Publishing, Paris. https://doi.org/10.1787/agr_outlook-2016-5-en
OECD/UN ECA/AfDB (2022) Africa’s Urbanisation dynamics 2022: the Economic Power of Africa’s cities, West African studies. OECD Publishing, Paris. https://doi.org/10.1787/3834ed5b-en
Ongoma V, Chen H (2017) Temporal and spatial variability of temperature and precipitation over East Africa from 1951 to 2010. Meteorol Atmos Phys 129(2):131–144. https://doi.org/10.1007/s00703-016-0462-0
Onyutha C (2021) Trends and variability of temperature and evaporation over the African continent: relationships with precipitation. Atmósfera 34(3):267–287. https://doi.org/10.20937/ATM.52788
Parker LE, McElrone AJ, Ostoja SM, Forrestel EJ (2020) Extreme heat effects on perennial crops and strategies for sustaining future production. Plant Sci 295:110397. https://doi.org/10.1016/j.plantsci.2019.110397
Pausata FSR, Gaetani M, Messori G, Berg A, de Souza DM, Sage RF, DeMenocal PB (2020) The greening of the Sahara: past changes and future implications. One Earth 2(3):235–250. https://doi.org/10.1016/j.oneear.2020.03.002
Pickson RB, Boateng E (2022) Climate change: a friend or foe to food security in Africa? Environ Dev Sustain 24(3):4387–4412. https://doi.org/10.1007/s10668-021-01621-8
Pogačar T, Casanueva A, Kozjek K, Ciuha U, Mekjavić IB, Bogataj LK, Črepinšek Z (2018) The effect of hot days on occupational heat stress in the manufacturing industry: implications for workers’ well-being and productivity. Int J Biometeorol 62(7):1251–1264. https://doi.org/10.1007/s00484-018-1530-6
Rigal A, Azaïs JM, Ribes A (2019) Estimating daily climatological normals in a changing climate. Clim Dyn 53(1–2):275–286. https://doi.org/10.1007/s00382-018-4584-6
Scherrer SC, Appenzeller C, Liniger MA (2006) Temperature trends in Switzerland and Europe: implications for climate normals. Int J Climatol 26(5):565–580. https://doi.org/10.1002/joc.1270
Sen PK (1968) Estimates of the regression coefficient based on Kendall’s tau. J Am Stat Assoc 63(324):1379–1389. https://doi.org/10.1080/01621459.1968.10480934
Sindikubwabo C, Li R, Wang C (2018) Abrupt change in Sahara Precipitation and the Associated circulation patterns. Atmos Clim Sci 8(2):262–273. https://doi.org/10.4236/acs.2018.82017
Sun W, Wang B, Zhang Q, Pausata FSR, Chen D, Lu G, Yan M, Ning L, Liu J (2019) Northern Hemisphere Land Monsoon Precipitation increased by the Green Sahara during Middle Holocene. Geophys Res Lett 46(16):9870–9879. https://doi.org/10.1029/2019GL082116
Tanner CB, Pelton WL (1960) Potential evapotranspiration estimates by the approximate energy balance method of Penman. J Geophys Res 65(10):3391–3413. https://doi.org/10.1029/JZ065i010p03391
Terry N, Galvin R (2023) How do heat demand and energy consumption change when households transition from gas boilers to heat pumps in the UK. Energy Build 292:113183. https://doi.org/10.1016/j.enbuild.2023.113183
Trisos CH, Adelekan IO, Totin E, Ayanlade A, Efitre J, Gemeda A, Kalaba K, Lennard C, Masao C, Mgaya Y, Ngaruiya G, Olago D, Simpson NP, Zakieldeen S (2022) Africa. In: Pörtner -O, Roberts DC, Tignor M, Poloczanska ES, Mintenbeck K, Alegría A, Craig M, Langsdorf S, Löschke S, Möller V, Okem A, Rama B (eds) Climate Change 2022: impacts, adaptation, and vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp 1285–1455. doi:https://doi.org/10.1017/9781009325844.011.
University of East Anglia Climatic Research Unit, Harris IC, Jones PD, Osborn T (2023) CRU TS4.07: Climatic Research Unit (CRU) Time-Series (TS) version 4.07 of high-resolution gridded data of month-by-month variation in climate (Jan. 1901- Dec. 2022). NERC EDS Centre for Environmental Data Analysis. https://catalogue.ceda.ac.uk/uuid/5fda109ab71947b6b7724077bf7eb753 (Accessed 31 October 2023)
Walsh JE, Mostek A (1980) A quantitative analysis of Meteorological anomaly patterns over the United States, 1900–1977. Mon Weather Rev 108:615–630. https://doi.org/10.1175/1520-0493(1980)108<0615:AQAOMA>2.0.CO;2
Wang R, Li L, Chen L, Ning L, Yuan L, Lü G (2022) Respective contributions of precipitation and potential evapotranspiration to long-term changes in Global Drought Duration and Intensity. Int J Climatol 42(16):10126–10137. https://doi.org/10.1002/joc.7887
World Meteorological Organization (2017) WMO Guidelines on the Calculation of Climate Normals. WMO-No. 1203
World Meteorological Organization (2015) Seventeenth World Meteorological Congress. WMO-No. 1157
World Meteorological Organization (1989) Calculation of Monthly and Annual 30-Year Standard Normals. WCDP-No. 10, WMO-TD/No. 341
World Meteorological Organization (2007) The role of climatological normals in a changing climate. WCDMP-61, WMO-TD/1377.
Zhang H, Wang L (2021) Analysis of the variation in potential evapotranspiration and surface wet conditions in the Hancang River Basin, China. Sci Rep 11:8607. https://doi.org/10.1038/s41598-021-88162-2
Zhong Z, He B, Chen HW, Chen D, Zhou T, Dong W, Xiao C, Xie S ping, Song X, Guo L, Ding R, Zhang L, Huang L, Yuan W, Hao X, Ji D, Zhao X (2023) Reversed asymmetric warming of sub-diurnal temperature over land during recent decades. Nat Commun 14:7189. https://doi.org/10.1038/s41467-023-43007-6
Acknowledgements
The authors are thankful to the Climatic Research Unit (CRU) for making the data used in this study publicly available.
Funding
The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.
Author information
Authors and Affiliations
Contributions
Conceptualisation and Methodology: KTCLKS, VO, Formal analysis and investigation: KTCLKS, VO, PS; Visualisation: KTCLKS; Writing - original draft preparation: KTCLKS, VO; Writing - review and editing: VO, PS.
Corresponding author
Ethics declarations
Competing interests
The authors have no relevant financial or non-financial interests to disclose.
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Lim Kam Sian, K.T., Sagero, P. & Ongoma, V. Precipitation, temperature and potential evapotranspiration for 1991–2020 climate normals over Africa. Theor Appl Climatol (2024). https://doi.org/10.1007/s00704-024-04963-1
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00704-024-04963-1