IMERG Early Run Example January 24th, 2020


Precipitation data from the GPM and TRMM missions are made available free to the public in a variety of formats from several sources at NASA Goddard Space Flight Center. This section outlines the different types of data available, the levels of processing, the sources to download the data, and some helpful tips for utilizing precipitation data in your research.

Beginner Resources



Data Visualization

Data FAQ

Learn about IMERG


Frequently Asked Questions

How do I get precipitation data for my specific location?

There are several sources for downloading and viewing data which allow you to subset the data to only include specific parameters and/or geographic locations. These include the GES DISCGiovanni and STORM. In Giovanni you can obtain data for a specific country, U.S. state, or watershed by using the "Show Shapes" option in the "Select Region" pane.

What happened to the TRMM Multi-satellite Precipitation Analysis (TMPA / 3B4x) data products?

The TRMM satellilte has been decommissioned and stopped collecting data in April 2015. The transition from the Tropical Rainfall Measuring Mission (TRMM) data products to the Global Precipitation Measurement (GPM) mission products has completed as of August 2019. The GPM IMERG dataset now includes TRMM-era data from June 2000 to the present, and other TRMM-era data has been reprocessed with GPM-era algorithms and is now available on the GPM FTP servers. TMPA data production ended as of December 31st, 2019 and the TRMMOpen FTP server has been shut down. Historical TMPA data is still available to download from the NASA GES DISC at:

Click here for more details on the transition from TMPA to IMERG. 

Am I allowed to use GPM data for my research?

Yes, in line with NASA's general data policy. Please refer to the GPM Data Policy for further details.

How do I give credit for using GPM data?
Where can I find detailed documentation on the precipitation algorithms?

Browse our directory of GPM & TRMM data products to locate your desired algorithm, then click on the links in the algorithm description under "Documentation". All documentation is also available at the Precipitation Processing System website

What is the spatial and temporal resolution of GPM data?

The resolution of Level 0, 1, and 2 data is determined by the footprint size and observation interval of the sensors involved.  Level 3 products are given a grid spacing that is driven by the typical footprint size of the input data sets.

For our popular multi-satellite GPM IMERG data products, the spatial resolution is 0.1° x 0.1° (or roughly 10km x 10km) with a 30 minute temporal resolution.

Visit the directory of GPM & TRMM data products for details on the resolution of each specific products.

Can I use images or videos from this site or other NASA websites?

For questions about permission for using NASA images and videos, please refer to NASA's official Media Usage Guidelines. For any additional questions please contact

Is it possible to subset GPM data?

There are several sources for downloading and viewing data which allow you to subset the data to only include specific parameters and/or geographic locations. These include the GES DISCGiovanni and STORM. In Giovanni you can obtain data for a specific country, U.S. state, or watershed by using the "Show Shapes" option in the "Select Region" pane.

What is the difference between "Near Real-time" (NRT) and "Production" / "Research" data?

GPM data products can be divided into two groups (near real-time and production) depending on how soon they are created after the satellite collects the observations. For applications such as weather, flood, and crop forecasting that need precipitation estimates as soon as possible, near real-time data products are most appropriate.  GPM near real-time (GMI & DPR) products are generally available within a few hours of observation.  For all other applications, production data products are generally the best data sets to use because additional or improved inputs are used to increase accuracy.  These other inputs are only made available several days, or in some cases, several months, after the satellite observations are taken, and the production data sets are computed after all data have arrived, making possible a more careful analysis.

For the GPM IMERG dataset, IMERG Early and Late Runs are the near real-time products, while IMERG Final Run is the research / production product. Click here to learn more about the differences between IMERG Early, Late and Final. 

PPS will be performing crucial server updates, scheduled preventive maintenance and data product verification starting on Thursday July 01, 2021 through Thursday July 08, 2021 (Thu Jul 1, 8:00 AM EST - Thu Jul 08, 2021 Time TBD). During this period PPS will finish producing GPM data products for June 2021. GPM July 2021 production data will then be placed on hold while PPS upgrades our servers and then analyzes the GPM July data after the OS update . Please see the schedule below for the specific details and times. July 1 - 5, 2021: PPS will be closing out monthly processing for June 2021 GPM...
PPS's new 'https://gpmweb2https' service is now accessible to the public and we have modified our website: All the previous links and source material referencing ftp://gpmweb2 have been or will be completely updated to refer to the new 'https://gpmweb2https' address. This effort will allow you to view documents and other content within your browser as you did before. As an example see:… PPS will also make '' ftps service available as an alternative. You can...
Due to recent changes to popular web browsers (i.e. Firefox, Edge, Chrome, etc.) PPS's gpmweb2 FTP content which was viewable with a web browser may no longer display. This content will be moving to an alternate 'HTTPS' service. Consequently, all the old links and source material referencing ftp://gpmweb2 will be updated to refer to 'https://gpmweb2https' once this service is activated for the PPS public website: These changes and the new 'HTTPS' service are expected to go into effect around or before the next PPS preventive maintenance downtime on Tuesday May 04...
This is the final reminder that starting on Tuesday January 19, 2021, PPS will transition from FTP access to FTPS access (main method) and HTTPS access (secondary method) for data transfer from the PPS's 'arthurhou' GPM Production data server Elimination of the less secure 'ftp' protocol is mandated by NASA/ GSFC security policy. This change will require PPS data users to retrieve data using alternative methods and tools. Please note that 'arthurhou' already supports FTPS and HTTPS data transfers. Details of how to access PPS FTPS and HTTPS services can be found at the links below: Click here...
The Precipitation Processing System is planning to migrate the (which includes to the CentOS 8 operating system. This update will mean that GPM near real-time (NRT) data will not be available to users during the period of the update. The action is planned for Monday, 7 December 2020. We intend starting at 14 UTC (09:00 EST). We hope the outage will be between 3-5 hours. During this period no GPM NRT will be available. Some data will not be produced at the usual time during this period and will be behind normal latency. No data will...

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