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Climate Data Collection

Identifier: WCDC

Scope and Contents

The Climate Data Collection consists of documents dated 1872 to 2019. Most of the materials consist of data sheets from the National Weather Service, Cooperative Observer Program, and Mountain States Weather Services, as well as from other sources such as the Colorado Amateur Radio Weather Net and other unknown sources. The earliest set of data was collected by local observers and submitted to the Smithsonian Institution or the U.S. Army Signal Service. In addition, the collection contains correspondence, newspaper clippings, photographs, observer contact information, and other miscellaneous weather information. The material is useful for providing insight into the climatic patterns of the Rocky Mountain region, particularly Colorado, but also Wyoming, Nebraska, New Mexico, and Montana. One large set of data documents more than forty years of Fort Collins, Colorado, weather, and another set documents Denver weather for more than sixty years. In addition, there is a small amount of climate information for New Jersey and Maryland.


  • Creation: 1872-2019

Restrictions on Access

There are no access restrictions on this collection. However, it is stored off-site, so advance notice is required.

Restrictions on Use

Not all of the material in the collection is in the public domain. Researchers are responsible for addressing copyright issues.


The Colorado Climate Center is part of the Department of Atmospheric Science at Colorado State University and helps the State of Colorado monitor climate. The organization was created in 1974 by the Colorado State University Agricultural Experiment Station, and its program includes Climate Monitoring, Climate Research and Climate Services, and provides information and expertise on Colorado's climate.

The Colorado Climate Center acquired the documents contained in this collection from various weather monitoring organizations including the National Weather Service's (NWS) Cooperative Observer Program (COOP) and Mountain States Weather Services (MSWS).

The NWS Cooperative Observer Program is a weather and climate observing network of more than 11,000 volunteers who record observations from locations all over the United States. COOP was created in 1890 under the Organic Act with a two-fold mission: "To provide observational meteorological data, usually consisting of daily maximum and minimum temperatures, snowfall, and 24-hour precipitation totals, required to define the climate of the United States and to help measure long-term climate changes and to provide observational meteorological data in near real-time to support forecast, warning and other public service programs of the NWS." The volunteer observers record daily temperature and precipitation, as well as occasional additional meteorological or hydrological data. These daily reports are sent monthly to the National Climatic Data Center (NCDC) or a NWS office.

Mountain States Weather Services is an official National Weather Service cooperative observer that provides meteorological consulting and weather forecasting. MSWS was established in 1977 by Jim Wirshborn in Fort Collins, Colorado, and was later sold in 2003 to Day Weather Inc., based in Cheyenne, Wyoming. Providing weather forecasts, real-time weather products and weather warning services to various governmental and civil organizations, the MSWS enlists the assistance of more than 100 weather observers to record daily climate observations and to alert the area about severe weather. Climate data is collected and posted on the Internet with both hourly and daily summary information. Day Weather Inc. is a weather forecasting service in existence since 1992 that provides broadcast services, customized local weather pages for newspapers and forensic meteorological analyses to the western United States.


123 linear feet (82 record cartons, 10 oversize folders)

Language of Materials



The Climate Data Collection contains more than 140 years, starting in 1872, of climate data which was primarily collected by local weather stations as part of the National Weather Service Cooperative Observer Program and also by the Mountain States Weather Services and Colorado Amateur Radio Weather Net. The collection consists primarily of weather data from Colorado as well as the Rocky Mountain region and some eastern states. There are also voluminous sets of Denver and Fort Collins, Colorado, weather data. A portion of the collection is digitized and online.


The boxed materials in the collection were originally roughly arranged chronologically and then alphabetically by station name. Materials within the first two series were maintained in chronological and alphabetical order as found or minimally rearranged for consistency.

The collection consists of 3 series in 82 boxes, 10 oversize folders, and 1 digital file:

Series 1: National Weather Service, 1893-2010

Subseries 1.1: Colorado station data, 1893-1984

Subseries 1.2: Denver data, 1948-2010

Series 2: Mountain States Weather Services, 1976-2019

Subseries 2.1: Station data, 1978-2019

Subseries 2.2: Fort Collins data, 1976-2019

Series 3: Smithsonian Institution and U.S. Army Signal Service, 1872-1889


The original part of the Climate Data Collection was donated to the Water Resources Archive by Nolan Doesken of the Colorado Climate Center in July 2008. Materials added as Subseries 2.2 were donated by Jim Wirshborn of Mountain States Weather Services in March 2010 (accession 2010015). Materials added as Subseries 1.2 (accession 2012070) were donated by Noah Newman of the Colorado Climate Center in January 2013. Materials added as Series 3 were given by Jim Wirshborn to Nolan Doesken who gave them to the Archive in July 2014. Subseries 2.2 was extended through 2016 with materials from Jim Wirshborn (accession 2016052), who gave a data spreadsheet as well. It was extended through 2017 (accession 2018009) and 2019 (2018041 and 2019033) with additional materials from Wirshborn. The latter accession also extended Subseries 2.1 through 2019.

Online Materials

Some data sheets in Subseries 2.2 have been scanned and are available through the Colorado State University Libraries website. In the electronic version of this document, direct links appear in context in some places. Some materials were digitized prior to donation. They are available on the National Oceanic and Atmospheric Administration's (NOAA) National Climatic Data Center website at


Processing was completed in September 2009. Materials were inserted in acid-free folders and rehoused in acid-free boxes. Staples and rubber bands were removed and replaced with plastic clips as needed. Self-stick notes were kept and placed on acid-free paper. Newspaper clippings and some other acidic materials were inserted between sheets of acid-free paper. Some blank documents and markers used previously by scanners were discarded. Processing of the original Subseries 2.2 addition was completed in May 2010 and consisted mainly of replacing binders with acid-free folders. Processing of the Subseries 1.2 addition was completed in May 2013 and consisted of replacing binders with acid-free folders and removing pages from plastic page protectors. Processing of the Series 3 addition was completed in April 2016 and consisted of inserting some sheets into polyester sleeves and all into oversize acid-free folders. Standard processing was completed in early 2017 for the 2016 accession, in April 2018 for that year's accession, and in March 2023 for the October 2018 and the August 2019 accessions.

Inventory Note

Note: Title information supplied by the archivist is bracketed. Estimated pagination is preceded by an "e."

Guide to the Climate Data Collection
Edited Full Draft
Prepared and revised by Vanessa Baca and Patricia J. Rettig; revised by Barbara S. Smith and Patricia J. Rettig; revised by Patricia J. Rettig
Copyright 2023
Language of description
Script of description
Language of description note
Finding aid written in English.

Repository Details

Part of the CSU Libraries Archives & Special Collections Repository

Fort Collins Colorado 80523-1019 USA