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NOAA's PRECipitation REConstruction over Land (PREC/L)

Mean files have been converted to netCDF4-classic format

Brief Description:

  • NOAA's Precipitation Reconstruction over Land (PREC/L)

Temporal Coverage:

  • Monthly values 1948/01 to Apr 2022 except the 0.5 degree data, which runs behind.
  • Long Term Mean 1981-2010

Spatial Coverage:

  • 2.5 degree latitude x 2.5 degree longitude global grid (144x72).
  • 88.75N - 88.75S, 1.25E - 358.75E.
  • 1.0 degree latitude x 1.0 degree longitude global grid (360x180).
  • 89.50N - 89.50S, 0.5E - 359.50E.
  • 0.5 degree latitude x 0.5 degree longitude global grid (720x360).
  • 89.75N - 89.75S, 0.25E - 359.75E.


  • Surface

Update Schedule:

  • Near Real-time at NOAA/CPC

Download/Plot Data: (FTP Access)

Variable Statistic Download File Create Plot/Subset
Precipitation Mean precip.mon.mean.2.5x2.5.nc plot
Precipitation Number of Gauges precip.mon.number_gauges.2.5x2.5.nc plot
Precipitation Long Term Mean precip.mon.ltm.2.5x2.5.nc plot
Precipitation Mean precip.mon.mean.1x1.nc plot
Precipitation Number of Gauges precip.mon.number_gauges.1x1.nc plot
Precipitation Long Term Mean precip.mon.ltm.1x1.nc plot
Precipitation Mean precip.mon.mean.0.5x0.5.nc plot
Precipitation Number of Gauges precip.mon.number_gauges.0.5x0.5.nc plot
Precipitation Long Term Mean precip.mon.ltm.0.5x0.5.nc plot

Usage Restrictions:

  • None

Detailed Description:

  • The monthly data set consists of three files containing monthly averaged precipitation totals. Precipitation is available at 3 spatial resolutions. The global analyses are defined by interpolation of gauge observations over land (PREC/L) and by EOF recon- struction of historical observations over ocean (PREC/O). Gauge observations are from over 17 000 stations collected in the Global Historical Climatology Network (GHCN), version 2, and the Climate Anomaly Monitoring System (CAMS) datasets. An OI technique of Gandin was used to assimilate the observations. The mean distribution and annual cycle of precipitation observed in the PREC/L showed good agreement with those in several published gauge-based datasets, and the anomaly patterns associated with ENSO resemble those found in previous studies. All maps are stored using a landmask as smoothing puts values well over the oceans. The 1x1 and 0.5x0.5 are stored with a from CPC at their ftp site which contains 1's and 0s. The 2.5x2.5 is stored using the CPC provided % land file. It has values for each gridbox from 0 to 100. We stored all values where the values were >0. You may decide to further mask the data using their land file and a different cutoff.


  • None

Related File Naming & Structure Information:

File Names:

  • /Datasets/precl/2.5deg/precip.mon.mean.2.5x2.5.nc.
  • /Datasets/precl/2.5deg/precip.mon.ltm.2.5x2.5.nc.
  • /Datasets/precl/1.0deg/precip.mon.mean.1x1.nc.
  • /Datasets/precl/1.0deg/precip.mon.ltm.1x1.nc.
  • /Datasets/precl/0.5deg/precip.mon.mean.0.5x0.5.nc
  • /Datasets/precl/0.5deg/precip.mon.ltm.0.5x0.5.nc

OpenDap File Names:

  • /thredds/dodsC/Datasets/precl/2.5deg/precip.mon.mean.2.5x2.5.nc
  • /thredds/dodsC/Datasets/precl/2.5deg/precip.mon.ltm.2.5x2.5.nc
  • /thredds/dodsC/Datasets/precl/1.0deg/precip.mon.mean.1x1.nc
  • /thredds/dodsC/Datasets/precl/1.0deg/precip.mon.ltm.11.nc
  • /thredds/dodsC/Datasets/precl/0.5deg/precip.mon.mean.0.5x0.5.nc
  • /thredds/dodsC/Datasets/precl/0.5deg/precip.mon.ltm.0.5x0.5.nc

Dataset Format and Size:

  • PSL standard NetCDF 31 Mbyte file for each monthly file.
  • PSL standard NetCDF 195 Mbyte file for 1x1 monthly file.
  • PSL standard NetCDF 746 Mbyte file for 0.5x0.5 each monthly file.

Missing Data:

  • Missing data is flagged with a value of -9.96921e+36f.


  • Chen, M., P. Xie, J. E. Janowiak, and P. A. Arkin, 2002: Global Land Precipitation: A 50-yr Monthly Analysis Based on Gauge Observations, J. of Hydrometeorology, 3, 249-266
  • Please note: If you acquire PRECL Precipitation data products from PSL, we ask that you acknowledge us in your use of the data. This may be done by including text such as PRECL Precipitation data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at / in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSL to justify keeping the PRECL Precipitation data set freely available online in the future. Thank you!


    Chen, M., P. Xie, J. E. Janowiak, and P. A. Arkin, 2002: Global Land Precipitation: A 50-yr Monthly Analysis Based on Gauge Observations, J. of Hydrometeorology, 3, 249-266

Original Source:

  • Dr. May (Mingyue) Chen
    Climate Prediction Center
    5200 Auth Road, #805B
    Camp Spings MD 20764
    Tel: (301) 763-8000 ext. 7506
    Fax: (301) 763-8125
    E-mail: mingyue.chen@noaa.gov
    original ftp: ftp://ftp.cpc.ncep.noaa.gov/precip/50yr/


  • Physical Sciences Laboratory: Data Management
    325 Broadway
    Boulder, CO 80305-3328