personal sites and galleries:

Atmospheric optics
mesoscale.ws
Missouri Skies
Kitao
weather-photography.com
Lightning Wizard
Brian Whittaker
Photon-echoes
polarimage.fi
Convection connection
Museum of time
Skylook
In the clouds photography
Chasing the Storm: Weather Photography

special sites:

Astromeeting
High Definition Earth-Viewing System
Bayerwald natur
Snow Crystals
Earth science picture of the day
Astronomy picture of the day
contrails.nl
Take a look at the sun
Sky Timelapse
Halo display 2004-11-22
Dutch Photo Zone
natuurfotografie.nl