TclWeather is a simple weather applet that periodically downloads meteorological data from NOAA's web site[L1 ]. The program first grabs the METAR[L2 ] report for the selected location. The location is selected from the application's control panel (which is selected by right clicking the ticker).

(Screenshots of TclWeather running under Tcl/Tk 8.3 in Linux/x86 and MsWindows.)

It then pushes the data through a home-made scanner (written as a Fickle specification file) and then displays it on a home-made ticker widget. It is to Tcl what gweather[L3 ] is to Gnome[L4 ]. Here's a screenshot of it in action (first on Linux then on MsWindows).

The applet is fairly customizable, from the color choices to scrolling speed and direction. One feature it supports, that I find lacking by many others, is that it allows for HTTP proxies as well as proxy authentication. This is useful if one wishes to run TclWeather behind, for example, a corporation's proxy server.

If your browser does not support PNG images you can get the JPG versions at


FW: Thanks, great software! But FYI, WinZip reports an invalid header. I had to use WinRAR (not that that's so bad).

So you want to do some METAR data decoding? Look at the file utils/METAR_decoding. For your convenience, the file is replicated at .

Post your flamebait and trollings below.

how far below?

Using Netscape 4.77 on RedHat linux 6.2, the black pixel in your PNG files is rendered as white... I'm not sure why this is. I've encountered this in an endless number of places, although PNG files generated by xv look just fine in netscape, and the PNG files that netscape screws up look just fine in xv.

Jason Tang: Odd. The images appear fine on my screen, under Mozilla (stable) and Debian/Woody. I had used the gimp to generate the PNG files, so perhaps it's a problem with that?

Frans Houweling writes, Just one detail: I had to change line 356 [of tclweather.tcl]

  named {set cmd [[$tw(browser) $url &]}


  named {set cmd [[list $tw(browser) $url &]}

To this I claim guilty as charged. I also found another problem while selecting the external browser. Both are fixed in release 1.11. The same errors exists in TclStock 1.10 and have been corrected.

Mike Tuxford: No flames from me. Very nice job. I didn't know anyone else was working with METAR data. I've sent email concerning what I was working on.

escargo 27 Aug 2003 - I am trying to get "no data from server" and "nothing to display". How should I go about determining why my network connection does not seem to be retrieving data? (This is when I set my location to any of the Minneapolis or the St. Paul locations on the "Location" tab. Checking other locations like Washington-Dulles also gets no data.) It looks like download_observation should somehow report its errors a bit more thoroughly.

Jason Tang: Weather Underground, from where I snarf the data, changed the layout of their page slightly. Release 1.12 (see above) corrects this.

escargo 28 Aug 2003 - I tested the new version and indeed it does work now. Thank you for your prompt attention. (You might want to note that you didn't change the version number in the code.)

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