UCSD Meteorology - The weather and climate site for UCSD/Scripps Institution of Oceanography. Includes lots of research on climate change.
Weather Channel - Good site for a variety of local, national, and international weather.
National Weather Service - National Weather Service Home Page. Great variety for both new and experienced weather buffs.
Latest El Nino Forecasts from NOAA - Great site for up to date information on El Nino and La Nina.
Latest El Nino Forecasts from the International Research Institute - Another great El Nino site that also includes a very useful Climate Dictionary.
World Climates - A great website for climate data from around the world.
Weather Base - Another great site for climate data from around the world.