The latest version of HadISD has been made available on the hadobs website. This version (v126.96.36.1993f) supercedes the preliminary version from earlier this year (v188.8.131.523p). There were further updates to the ISD source data for the year 2013 since the preliminary dataset was created in January, but no changes in earlier years.
Extra variables have been pulled through from the ISD source data in this release, but these have not been quality controlled. They are wind gust and precipitation period. As these were not quality controlled there has been no further increment of the version number. If you use these variables then be aware that they are provided as is, with no guarantee as to their quality.
As always, if you find anything untoward in the data, please contact the dataset maintainers.