HadISD v342_202508p - potentially the final release

As of August 29th 2025, the ISD dataset has stopped receiving updates.  Therefore the HadISD can no longer append new data to the end of the station time series.

 

Snapshot on 4th September 2025 of this page: https://www.ncei.noaa.gov/operating-system-upgrade-outage

 

Given the timing of this change, we have released v342_202508p as normal as a standard "preliminary" version using the station lists from January 2025.  In due course, we shall see if or how best to release a 2025f version.

But for now, the HadISD dataset is coming to the end of its run.  Version 1.1.0.2011f was released in 2012, as an annually updating dataset covering 1st January 1973 to 1st January 2012 with 6103 stations.  Version 3.4.2.202508p is a monthly updating dataset covering 1st January 1931 to 29th August 2025 with 10,269 stations.

As a replacement, the Global Historical Climatology Network hourly (GHCNh) has built on the successes and developments within HadISD.  GHCNh is still under active development, and so will improve over the coming years to fill the gap that ISD/HadISD will leave.

HadISD v3.4.2.202501p

As the ISD is still currently being updated, we have made the first annual update for 2025, v3.4.2.202501p.  As usual, we've re-run the station selection and now there are 10,276 stations in the dataset.

This update was run on a new compute solution, but a comparison to a version run on the old one showed only very minor changes for the Distributional Gap and Climatological checks - which are likely to have arisen in the Gaussian curve fitting for these tests.  Only a few stations have moved flagging categories in the summary plots, and only for these tests and those which assess overall flagging rates (month-clearing).  We have therefore accepted the migration as successful with no changes made to the underlying code.