GHCN monthly station data
monthly climate dataset coms from NOAA/NCDC.
In late 2008 it contained 20586 precipitation stations, 7279 mean
temperature stations, 4965 min/max temperature stations and 2667
pressure stations, varying in length from hundreds of years to just a few.
The data comes in two flavours, adjusted and all
(unadjusted). The first set has been corrected for urban effects and
other biases by comparing urban stations to nearby rural stations.
The adjusted data are only available for a few countries.
I have post-processed the NCDC data by combining all time series
for a given station. At the momen this is done very crudely. For
each year, the first series with valid data is chosen. I plan to
merge these series more intelligently, using all data and taking into
account the possibility of biases.
The quality of the data varies. Most problematic are very old data,
before observations were standardised enough (1855, 1905, 1950 are
common disconinuities), and very new data from the GTS. Most errors
have been removed by the quality control system at NCDC, but
inevitably some remain. It always pays to have a glance at
the time series. It may also be worth it to check whether the
coordinates match with those you expect, e.g., in Google Earth - some
stations are mislocated. Please report errors back to me and NCDC.
The database is updated from NCDC into the Climate Explorer once