The collection consists of monthly weather records from U.S. Army Forts stations (~1820-1871), U.S. Army Signal Service Stations (1871-1892), Smithsonian Institution voluntary observer network (1848-1875), and other stations which conducted weather observations in the 19th century. Observations were generally conducted three times daily, around 7am, 2pm and 9pm. The voluntary and Signal Service stations were transferred to the newly-created U.S. Weather Bureau in 1891.

Hourly observations journal from the National Observatory in Washington DC. The observatory is the first station in the United States to produce hourly observations over a long period. The images were captured from microfilm held at the National Archives and Records Administration (NARA) in College Park, MD. Scanning performed by a Climate Database Modernization Program (CDMP) contractor. Period of record July 1842-February 1913.

The publication of the Bulletin of International Simultaneous Observations, began July 1, 1875, with daily maps added in 1877. It was published for distribution among cooperative observers only, and continued daily through 1887. Observations were taken simultaneously at 7:35am (later changed to 7am) Washington mean time. The published daily bulletins cover the period from January 1, 1875, to June 30, 1884, while the corresponding daily charts extend from January 1, 1875, to December 31, 1887.

Surface Observations from Punta Arenas, in extreme southern Chile. WMO station ID 85934. Period of record 1896-1954. The original forms were scanned at the Museo Salesiano Maggiorino Borgatello, a private regional museum in Punta Arenas with funding provided by NOAA through the Environmental Services Data and Information Management (ESDIM) program carryover.

Weather and soil temperature observations from foreign countries, taken by foreign and American observers. Includes NOAA forms collected and archived at NCDC, and voluntary observer forms taken in Mexico, Central American and the Caribbean in the 19th century. Scanned from microfilm held at the National Archives. Scanned as part of the Climate Database Modernization Program.

Mexican Surface Daily Observations taken at 94 observatories located throughout Mexico, beginning in 1872 and going up through 1981. The data resided on paper records stored in non-climate-controlled conditions, and were therefore subject to deterioration and loss. This Climate Dabase Modernization Program task set up digital cameras to image these records, creating color .jpg images of the Mexican National Meteorological Service forms.

Surface weather observation forms for 26 stations in Uruguay. Period of record 1896-2005, with two to eight observations per day. Files created through a collaboration between NCDC's Climate Database Modernization Program (CDMP) and the Uruguayan National Meteorological Service (NMS). Paper records remained custody of the NMS, whose staff captured .jpg images of the records using a Canon Powershot A80 digital camera. The images were sent via CD-ROM to CDMP contractors, who loaded them to this library and entered the indexing metadata.

Phenology is the scientific study of periodic biological phenomena, such as flowering, breeding, and migration, in relation to climatic conditions. The few records in this library document blooming dates of plants including fruit trees, and also bird migration and other animal activity.

Preliminary Local Climatological Data, recorded since 1970 on Weather Burean Form 1030 and then National Weather Service Form F-6. The preliminary climate data pages consist of 3 parts: Part 1 is the site information including the station location, the month and year of the report, and the latitude and longitude of the station. Part 2 is the daily information which consists of columns of data, with one row of data for each day of the month. The day runs from 0000 to 2359 Local Standard Time (0100 to 0059 Daylight Savings Time).

Wind and radiation data from stations in the National Weather Service Cooperative Observers Network. Some precipitation and pressure forms are mistakenly placed in this library.