QMetar
Applet showing current weather observations
is a free (GPL) multi-platform weather applet which shows current weather observation (temperature/dewpoint, wind, pressure, cloud cover, weather phenomena as rain or snow, as broadcasted by airports), tide times, and sunrise/sunset times. It resides as an icon in the system tray and displays the full information in a separate window.
QMetar is based on kweather which was part of KDE3 but unfortunately longer of KDE4. It was ported to Qt to make it multi-platform and extended to show tidal...