Articles | Volume 5, issue 2
Research article
29 Sep 2016
Research article |  | 29 Sep 2016

Expanding HadISD: quality-controlled, sub-daily station data from 1931

Robert J. H. Dunn, Kate M. Willett, David E. Parker, and Lorna Mitchell

Abstract. HadISD is a sub-daily, station-based, quality-controlled dataset designed to study past extremes of temperature, pressure and humidity and allow comparisons to future projections. Herein we describe the first major update to the HadISD dataset. The temporal coverage of the dataset has been extended to 1931 to present, doubling the time range over which data are provided. Improvements made to the station selection and merging procedures result in 7677 stations being provided in version of this dataset. The selection of stations to merge together making composites has also been improved and made more robust. The underlying structure of the quality control procedure is the same as for HadISD.1.0.x, but a number of improvements have been implemented in individual tests. Also, more detailed quality control tests for wind speed and direction have been added. The data will be made available as NetCDF files at and updated annually.

Short summary
We have extended the sub-daily, integrated HadISD back to 1931 to double the time coverage of the dataset. We have updated and improved the station selection and merging procedure, which will be rerun on an annual basis to prevent it becoming out of date. The quality-control code has been rewritten from IDL to Python2.7 to make it clearer and more accessible. We have also calculated humidity and heat-stress variables in HadISD.2.0.0. This increases the value and applicability of this dataset.