U.S. weather data for temperatures, winds, precipitation (rainfall/snowfall/hail), and other key measurements can usually be obtained from the office of the state climatologist in the region(s) you're interested in.

In Colorado, for example, the state climatology office is the Colorado Climate Center at Colorado State University.

To find a comparable office in another state:

• Visit StateClimate.org (American Association of State Climatologists). The site also provides information and links to six regional offices (see Regional Climate Centers, below)
• Or search for "state climatologist" plus the state's name in your favorite search engine.
• For international locations, try a similar search engine approach.
  
  

What if I need data from more than one U.S. state?

• Map of U.S. Regional Climate Centers, courtesy Desert Research Institute: www.wrcc.dri.edu/rcc.html
  
  

Follow the links provided on the map provided at the link above, or go directly to:

• Northeast Regional Climate Center
• Southeast Regional Climate Center
• Southern Regional Climate Center
• Midwest Regional Climate Center
• Western Regional Climate Center
  

What about another country?

The World Meteorological Organization is a good place to start

• For aggregated observing system data
• To find the national meteorological service(s) in your region of interest