Discovery and analysis of historic weather data strengthens climate knowledge
GENEVA 16 April 2015 (WMO) - A World Meteorological Organization panel has concluded that a temperature of -25.6°C observed at Eweburn, Ranfurly in New Zealand on 17 July 1903 holds the record as the coldest temperature recorded for the Southwest Pacific Region.
Over the last several months, a WMO international committee of experts conducted an in-depth investigation of the extreme for the Southwest Pacific region (WMO Region 5). The investigation was conducted with the support of New Zealand’s National Institute of Water and Atmospheric Research (NIWA) for the WMO Commission for Climatology’s World Archive of Weather and Climate Extremes, the official site for weather and climate extreme records.
The investigating committee was composed of climate experts from Australia, Egypt, France, Libya, Morocco, New Zealand, Russia, Spain and the United States of America. It was established following the 2011 discovery by NIWA staff of the Eweburn, Ranfurly 1903 temperature observation of -25.6°C (-14°F). The discovery occurred during the digitization of historical daily records kept in paper format, which were not previously present in NIWA’s climate database.
As part of the international investigation, the additional discovery of a historic 1868 New Zealand meteorological report was uncovered by WMO committee member and NIWA scientist Gregor Macara. It was this report that indicated weather instrument shelters for temperature measurements were in use in New Zealand at least as early as 1868. Because the degree of exposure of temperature sensors can play a critical role in the correct measurement of temperature, that additional report, validating the type of instrument shelter likely used in the 1903 temperature observation, was useful in the WMO committee’s evaluation.
This cold extreme in New Zealand was part of the aftermath of a major snowfall event that occurred just prior to the cold event on 10/11 July 1903. The cold event was significant because of its long duration, its severity, and its geographical extent. A number of vivid newspaper accounts of the severe cold at that time were uncovered and discussed by the WMO committee.
“This investigation demonstrates the need for continued and diligent discovery, evaluation and digitisation of all climate records around the world. The end result is an even better set of climate data for analysis of important global and regional questions involving climate variability and change,” said Professor Randall Cerveny, chief Rapporteur of Climate and Weather extremes for the WMO.
A full list of weather and climate extremes is available at the WMO Archive of Weather and Climate Extremes (http://wmo.asu.edu/) This includes the world’s highest and lowest temperatures, rainfall, heaviest hailstone, longest dry period, maximum gust of wind, as well as hemispheric weather and climate extremes
The World Meteorological Organization is the United Nations System’s authoritative voice on Weather, Climate and Water
WMO website: www.wmo.int
For more information, please contact: Clare Nullis, Media Officer, Communications and Public Affairs, Tel: +(41 22) 730 8478; (41-79) 7091397 (cell), e‑mail: cnullis(at) wmo.int .
Thomas C. Peterson [NOAA's National Centers for Environmental Information and president of the WMO Commission for Climatology]
Manola Brunet [Dept. of Geography, University Rovira i Virgili, Spain and co-chair of the WMO CCl OPACE II working group]
Fatima Driouech [Climate Studies Service at the Direction de la Météorologie nationale of Morocco and co-chair of the WMO CCl OPACE II working group]
Pierre Bessemoulin [Director of Climate Services (retired) at METEO-FRANCE and past President of WMO Commission for Climatology (CCl)]
Andrew Tait [Principal Scientist – Climate, NIWA, New Zealand]
Andrew Harper [Climate Scientist, NIWA, New Zealand]
Gregor Macara [Climate Scientist, NIWA, New Zealand, WMO co-Rapporteur on World Weather and Climate Extreme Records]
Ali Eddenjal [Libyan National Meteorological Center (LNMC), WMO co-Rapporteur on World Weather and Climate Extreme Records]
Alexander Sterin [Russian Research Institute for Hydrometeorological Information- World Data Center, Russia]
Blair Trewin [Climate Information Services, Australian Bureau of Meteorology]
Dushmanta R. Pattanaik [India Meteorological Department, India, WMO co-Rapporteur on World Weather and Climate Extreme Records]
Randy Cerveny [School of Geographical Sciences, Arizona State University and WMO co-Rapporteur on World Weather and Climate Extreme Records]