This is a top level index page. The purpose is just to give an easy entry point to the various postings that compare GHCN Version 1 with GHCN Version 3. ( If I ever get around to doing a ‘vs V2’ posting set those will be indexed here as well, but I’m not seeing a lot of reason to do that since others have already compared v2 and v3.)

I have put up posting of various geographies, and of the source code. There will also be various graphs in the postings as well along with various “by country” comparisons as I get them done (over a longer period of time).

So not a lot of new information from me in this posting, just links to make it easy to find the series.

The top level summary report of my observations is at this link:


In Total

The Earth, taken as a whole:


Comparing Northern Hemisphere to Southern Hemisphere shows very different effects:


A different way of looking at the changes between v1, v2, and v3 as seasonal shifts over the aggregate of the data:


By Continent / Region








Individual Country Examinations

The “Country Codes” change between v1 and v2/v3, so we need a ‘map’ to tell us what is what:


This series will be a ‘work in progress’ for quite a while as there are over 100 countries in the world…



The Source Code and Prior Works

Should anyone wish to “Quality Check” my code, here it is. I don’t think I have any “bugs” in it, but every programmer always thinks that. I’ve done a “desk check” and then “sanity checked” some of the intermediate values in the data. Also, the core of this code was used in the prior series of programs looking at v2 data. These programs are mostly just minor adjustments for the changed data formats (where the temperatures are located in a record, size of station ID, etc.) and the core function of the older code was not changed. The only significant difference between the dT/dt code and this dP/dt code is that I changed the sign on the “Delta Temperature” running total so that I could avoid needing to do an inversion of sign in the spreadsheet that makes the graphs.

(The older dT/dt field showed “how the past temperature had to change to become today”, so if it was 0.8 C hotter today, it showed a value of positive 0.8 C. This code is to show “how was the past in terms of today” so that colder past needs to be shown as -0.8 C as it was colder by 0.8 C then. This, then, lets us take the v3 value of, say, -0.8 and subtract the v1 value of, say, -0.3, and find the difference is -0.5 C; that is, the RECORD of temperatures in v3 was made 1/2 C colder for that item in the past.)


The older dT/dt series of reports and various items having to do with the processing are covered in the topic area

https://chiefio.wordpress.com/category/dtdt/ at the right hand side of the page.

Various other observations on the NCDC and GHCN products and data are covered in the topic area:


Also at the right side of the page.

This page will likely change a little bit for the next several months as I work through various views of the data and different subsets.

Subscribe to feed