Monthly Precipitation Percentile

This map shows monthly precipitation percentiles below the 20th percentile and above the 80th percentile for the globe.

The percentiles shown indicate a ranking of precipitation (for the month of the year shown on the plot), with the 0th percentile being the driest and the 100th percentile (shown as 1 on the plot) being the wettest in the 1981-2010 climatology. Green and dark green shading represent values above the 80th and 90th percentile, respectively; regions shaded in light and dark brown indicate precipitation below the 20th and 10th percentile, respectively, with respect to the 1981-2010 climatology for that calendar month of the year. Grey areas on the map mask out regions that receive less than 10 mm/month of precipitation on average in the 1981-2010 climatology for the month of the year displayed on the plot.

The data used in this map are from the NOAA Climate Prediction Center's CAMS_OPI data set. "CAMS" is an acronym for the "Climate Anomaly Monitoring System" in use at the Climate Prediction Center (CPC) at the U.S. National Centers for Environmental Prediction (NCEP). "OPI" stands for "Outgoing longwave radiation Precipitation Index" (the satellite precipitation estimates are based upon longwave radiation observed by polar-orbiting satellite).

Dataset Documentation

Monthly Precipitation Percentile

CAMS_OPI monthly precipitation on a 2.5° lat/lon grid
Data Source
NOAA NCEP Climate Prediction Center, CAMS_OPI
Monthly precipitation percentiles based upon the 1981-2010 base period


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