1

I downloaded data from http://climate.geog.udel.edu/~climate/html_pages/download.html in order to retrieve temperature and precipitation data.

What I actually want is mean temperature and precipitation over a long time-span (e.g. from 1950 to 1990) in gridded format in order to match the grids with other datasets. The problem is that I just do not manage to open the .clim-datafiles provided on the website. The specific datasets I downloaded were air_temp.clim.Z (6.4MB) and precip.clim.Z (7.8MB).

I am using QGIS 3.4. Crayfish (suggested by some other website) does not allow me to open any datasets. Any solutions?

3

The file is just a zipped text file without headers.

First you need to unzip the file, I would suggest 7-zip if on Windows.

If you open it up in notepad you would see:

-179.750  89.750  -32.2  -34.6  -32.4  -27.2  -12.5   -1.9   -0.5   -1.4   -9.9  -18.9  -27.0  -33.2  -19.3
-179.750  89.250  -32.4  -34.8  -32.3  -27.1  -12.4   -1.9   -0.6   -1.5   -9.9  -19.0  -27.2  -33.1  -19.4
-179.750  88.750  -32.6  -34.9  -32.1  -27.1  -12.2   -1.9   -0.6   -1.6   -9.9  -18.9  -27.1  -32.9  -19.3
-179.750  88.250  -32.9  -34.7  -31.9  -27.0  -12.0   -1.9   -0.7   -1.6   -9.6  -18.6  -27.0  -32.4  -19.2
-179.750  87.750  -32.9  -34.4  -31.4  -26.8  -11.8   -1.9   -0.6   -1.7   -9.6  -18.4  -26.9  -32.2  -19.0
-179.750  87.250  -33.1  -33.6  -30.6  -26.5  -11.4   -1.9   -0.6   -1.7   -9.2  -17.9  -26.6  -31.3  -18.7
-179.750  86.750  -33.3  -32.4  -29.3  -26.1  -10.9   -1.9   -0.6   -1.6   -8.6  -17.0  -26.3  -30.1  -18.2
-179.750  86.250  -33.6  -31.3  -28.2  -25.8  -10.5   -1.8   -0.6   -1.6   -8.0  -16.2  -25.9  -29.1  -17.7
-179.750  85.750  -33.8  -30.9  -27.8  -25.7  -10.3   -1.8   -0.6   -1.6   -7.8  -15.9  -25.7  -28.7  -17.5
-179.750  85.250  -33.9  -31.0  -28.0  -26.0  -10.4   -1.8   -0.7   -1.6   -7.8  -15.9  -25.8  -28.8  -17.6
-179.750  84.750  -34.2  -31.3  -28.4  -26.3  -10.5   -1.8   -0.8   -1.7   -7.8  -15.9  -25.8  -28.9  -17.8

So the first field is longitude, and the second in latitude, as outlined in the readme document from the page linked:

http://climate.geog.udel.edu/~climate/html_pages/README.lw.html

So once the data is unzipped, simply add it to QGIS using "Add Delimited Text Layer" (Layer> Add Layer> Add Delimited Text Layer...).

Using the following settings (the important parts being that you don't have a header row, and it uses double space as delimiter so we use space and discard the empty fields):

enter image description here

The final result:

enter image description here

Zoomed in:

enter image description here

  • Thanks! Works perfect. – philsch Jun 5 at 12:22
  • No problem. Welcome to GIS StackExchange. – HeikkiVesanto Jun 5 at 12:39

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