Increasing the comparability of extreme air temperature measurements for meteorology and climate studies

Short Name: COAT, Project Number: 19SIP06
Image showing a thermometer on a hot summers day
Thermometer on a hot summers day

Promoting and facilitating air temperature instruments and methods compatibility

The success of climate policies partly will depend on the quality of underlying data, such as for air temperature measurements. Currently, air temperature data is captured by monitoring networks using various combinations of thermometer models and solar radiation shields, since there is no agreed ‘reference system’ to ensure comparability and accuracy. This is especially significant in Arctic regions where measurement can be challenging and susceptible to climate variability. The World Meteorological Organization (WMO) recommended that field inter-comparisons of these instruments be performed to improve comparability, in response to which the EMRP MeteoMet2 project produced a feasibility study and developed procedures. That project identified a need for best practice guidance to support user communities.


This project will facilitate field inter-comparisons by developing and validating protocols for measuring performance limits of thermometers and radiation shields. This will be submitted to WMO for consideration as a reference document to support harmonisation of future inter-comparisons. Best practice guidance for air temperature measurement in arctic conditions will also be produced and submitted for consideration in WMO’s Guide to Climatological Practices in 2023. If adopted by the meteorological and climate communities, such guidance will support research communities by enabling a better understanding of air temperature measurements. In turn, the resulting, more accurate, air temperature data will help guide climate policymakers to implement more appropriate climate policies.


Participating EURAMET NMIs and DIs
CEM (Spain)
INRIM (Italy)
Other Participants
Consiglio Nazionale delle Ricerche (Italy)
Eidgenössische Departement des Innern (Switzerland)