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| Prepared by: FAO/NRCB, Agrometeorology Group |

Rainfall Monitoring

Maps indicate respectively:
  • the monthly total rainfall amount (in millimeters),
  • and
  • the monthly rainfall percentage of normals (in percentage).

Data input for creating the rainfall maps are provided by the Global Precipitation Climatology Centre (GPCC). GPCC has been established in year 1989 on request of the World Meteorological Organization and it is operated by the Deutscher Wetterdienst (DWD, National Meteorological Service of Germany) as a German contribution to the World Climate Research Programme (WCRP). Mandate of GPCC is the global analysis of monthly precipitation on earth’s land surface based on in situ rain gauge data. Since its start, the centre is the in situ component of the WCRP Global Precipitation Climatology Project (GPCP).

For producing the rainfall maps two GPCC products are used: the First Guess Product and the Monitoring Product. Both are gauge-based gridded monthly precipitation data sets for the global land surface at a spatial resolutions of 1.0° x 1.0° geographical latitude by longitude. The First Guess Product is used only for the last two available months.

The GPCC First Guess Product of the monthly precipitation anomaly is based on interpolated precipitation anomalies from about 6,000 stations worldwide. Data sources are synoptic weather observation data (SYNOP) received at DWD via the WMO Global Telecommunication System (GTS) and climatic mean (mainly 1951-2000) monthly precipitation totals at the same stations extracted from GPCC’s global normals collection. An automatic-only quality-control (QC) is applied to these data. Since September 2003, GPCC First Guess monthly precipitation analyses are available within 5 days after end of an observation month.

The GPCC Monitoring Product of monthly precipitation for global climate monitoring is based on SYNOP and monthly CLIMAT reports received near-realtime via GTS from ca. 7,000 –8,000 stations (after high level QC) and is available within about 2 months after observation month. This is the GPCC product with the longest history: Operational monthly analysis started with year 1986 and has continuously been done every month since then. The analyses are based on automatic and intensive manual quality control of the input data.

To produce the rainfall maps, FAO has developed a specific application for increasing the original spatial resolution of 0.1° x 0.1° geographical latitude by longitude. To otain this, a spatial interpolation method (Kriging) is applied to the initial grid of 1.0° x 1.0° resolution (360 by 180 points) to create a new grid of 0.1° x 0.1° resolution (3600 x 1800 points).

Note: click on one icon to select the region of interest. Then, select year and month to see what maps are available. Click on one item of the list to display the map.

year month map
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