The data sets available on this web site were created using the PRISM
(Parameter-elevation Regressions on Independent Slopes Model) climate
mapping system, developed by Dr. Christopher Daly, PRISM Climate Group director.
PRISM is a unique knowledge-based system that uses point measurements of
precipitation, temperature, and other climatic factors to produce continuous,
digital grid estimates of monthly, yearly, and event-based climatic parameters.
Continuously updated, this unique analytical tool incorporates point data, a
digital elevation model, and expert knowledge of complex climatic extremes,
including rain shadows, coastal effects, and temperature inversions. PRISM
data sets are recognized world-wide as the highest-quality spatial climate
data sets currently available. PRISM is the USDA's official climatological data.
PRISM data sets were developed
through projects funded partly by the USDA
Natural Resources Conservation Service, USDA
Forest Service, NOAA
Office of Global Programs, and others. However, there
is little operational funding for maintaining and updating
or expanding the data sets. Data are provided as a public
service for a limited time. If you find them valuable, please
consider doing your part to support the PRISM Climate Group. Contact
us for details at 541-737-2531.
Use this site to access
up-to-date and historical monthly climate data sets and graphics
for the US, to explore our data sets or
extract a time series of data at a point location,
to view related papers and presentations, or access a list of contacts.
Note that the historical monthly climate data sets have not been parsed into regions
smaller than the US (e.g. state, county, watershed, ...).
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