Thursday, March 26, 2015

GHCN Monthly data portal

I am planning to add station data to the GHCN V3 monthly portal. Not monthly data which would be cumbersome, but annual average. This is useful for plotting and trends.

There is a trial below. Each link leads to the NOAA GHCN station summary, as before, but the radio button brings up a page with a table of the annual averages, along with a brief metadata and a map (the station is in the middle). There is a table for unadjusted data, and below for adjusted. Both are then repeated in CVS format, for import into Excel. The table of links is searchable (Ctrl-F), and can take a while to load. I'll probably add a graphing and trend calculation capability.

In calculating the annual averages, I eliminated years with less than 9 months data. I also (before) removed data with flags indicating unreliability.  Then I infilled missing months with the overall mean for that station/month (else seasonal effects add a lot of noise). Then I calculated the simple average of the infilled data.


  1. Nice work, Nick. Just tossing these out as ideas:

    If you had collapsable menus for each country, and you alphabetized the list of stations, it would make this significantly more useful.

    And of course a search engine that let you search for particular stations.

    I'd also add the station ids as a column.

    Anyway, thanks for your efforts.

    1. Thanks, Carrick. One reason I've kept everything on one page with GHCN order (by country) is that it is searchable with Ctrl-F. Menus by country might not work so well - the US would have 1938, and Australia 588 entries. I could use frames, but they would inhibit global searches. I'll try a list of commonly used country links at the top. I could also have buttons to request re-order - eg alphabetical, but I'm not sure how useful people would find that.

      I could display ID's; thinking of loading time, but they are there anyway in the links. They are in the info when you click. I'll look at ways of speeding loading, which may make all this easier.