What follows are directions for upgrading from specific versions.
The part of the configuration file dealing with the presentation layer has been split off into a separate file skin.conf. Hence, once again, the installation script setup.py will NOT merge your old configuration file into the new one. You will have to re-edit weewx.conf to put in your customizations. You may also have to edit skin.conf for whatever skin you choose (right now, only skin, Standard comes with the distribution).
The URL for the radar image is now in the template. If you don't live in the Pacific Northwest, you will probably want to change it! You can find it in $WEEWX_ROOT/skins/Standard/index.html.tmpl and searching for "radar."
The directory 'templates' is no longer used; it has been replaced with directory 'skins'. You may delete it if you wish:
rm -r $WEEWX_ROOT/templates
Because the configuration file weewx.conf changed significantly going from V1.4 to V1.5, the installation script setup.py will NOT merge your old configuration file into the new one. You will have to re-edit weewx.conf to put in your customizations.
Option clock_check, previously found in the [VantagePro] section, is now found in the [Station] section. The install program will put a default value in the new place, but it will not delete nor move your old value over. If you have changed this value or if you can't stand the thought of clock_check appearing in two different places, you should delete the old one found under [VantagePro] and make sure the new value, found under [Station] is correct.
Two Python files are no longer used, so they may be deleted from your installation if you wish:
rm $WEEWX_ROOT/bin/weewx/processdata.py
rm $WEEWX_ROOT/bin/weewx/mainloop.py
In addition, file readme.htm has been moved to subdirectory $WEEWX_ROOT/docs, so the old one can be deleted:
rm $WEEWX_ROOT/readme.htm