Quality Controlled Datasets
Selected subsets of monthly, daily, hourly and sub-hourly (5-minute) USCRN/USRCRN data are available as text files for easy access by users ranging from the general public to science experts. The most useful variables, including air temperature, precipitation, solar radiation, surface temperature, soil moisture and soil temperature data, are available. Files contain raw observations with quality flags, as well as calculated variables. Calculated data are shown only if a sufficient amount of source data passes its quality control tests; otherwise these values are set to a missing value.
For the daily, hourly and sub-hourly data, users can retrieve the entire archive of data by downloading the most recent file in the snapshots subdirectory. The updates subdirectory in the daily and hourly directories contain a record of the real-time daily/hourly data transmitted over NOAAPORT. Detailed descriptions of the files and variables are available in the documentation links listed below.
Monthly data are found in the Monthly01 directory. Each station file contains monthly temperature, precipitation, global solar radiation, and surface infrared temperature data in text format for the station's period-of-record.
The Daily01 directory contains files with each station's daily data by year. Daily air temperature, precipitation, global solar radiation, relative humidity, surface infrared temperature, soil moisture and soil temperature data are shown in text format.
The Hourly02 directory contains files with each station's hourly data by year. Hourly data include: air temperature, precipitation, global solar radiation, relative humidity, surface infrared temperature, soil moisture and soil temperature.
The Subourly01 directory contains files with each station's sub-hourly (5-minute) data by year. Sub-hourly data include: air temperature, precipitation, global solar radiation, surface infrared temperature, relative humidity, soil moisture and temperature, wetness, and 1.5 meter wind speed.
Frequently Asked Questions
How do I read the ftp data files?
In each product folder there is a README.txt file that explains the file layouts and how to read the data within the files. You may use an ftp client (e.g. FileZilla) to download the files; however, most modern browsers will also download them.
Which ftp data files should I select?
The files in the yearly subdirectories are updated frequently and contain all the data for that year for each station. The entire period of record for all stations is available for download from the snapshots subdirectory. The updates subdirectory in the daily and hourly directories contain a record of the real-time daily/hourly data transmitted over NOAAPORT. For more detailed information, see the documentation links shown above.
What are the columns for each data file?
In each product folder, the file HEADERS.txt is designed to be prepended to the data for use with spreadsheet programs, data extraction tools (e.g. awk) or any other programming language. This file contains the following three lines: Field Number, Field Name and Unit of Measure.
How are hourly, daily, and monthly values calculated in USCRN quality controlled datasets?
USCRN observations are processed using calculation approaches and rounding methods advised by the National Data Stewardship Team, a group of weather and climate data experts from NCEI, NWS, USDA, universities, and state climate offices.
Why do some stations not report some measurements?
Unlike the U.S. Climate Reference Network (USCRN), the U.S. Regional Climate Reference Network (USRCRN) stations do not measure solar radiation, surface temperature, relative humidity or soil variables; those fields are shown as missing values in the data files.
Why are there no wind reports in ftp products?
The wind instrument on a USCRN station tower is mounted at the same height as the air intakes to the temperature sensors, which is usually 1.5 meters above the ground. The wind speed instruments were deployed for studying the environments of the temperature measurements, and are not comparable to the 10-meter wind measurements with which most people are familiar which are taken at airports. To avoid confusion, these data are only included in the sub-hourly files. However, other calculated wind measurements can be viewed in the Reports web tool.
Where can I find 5-minute data?
Some 5-minute data are available in the NCEI Climate Data Online system in the Quality Controlled Local Climate Data Products for USCRN stations listed at http://cdo.ncdc.noaa.gov/qclcd/QCLCD. Bulk transfers of 5-minute data for research purposes are best handled by NCEI Customer Service at http://www.ncdc.noaa.gov/oa/about/ncdcordering.html. USCRN contacts can also help direct persons with special requests. See our Contacts page for details.
Who can I contact for help?
USCRN personnel can help. See our Contacts page for details.