GPM IMERG V07¶

Integrated Multi-satellitE Retrievals for GPM (IMERG) Version 07

Update delayed

At a glance¶

Note on period: V07B Final (GPM_3IMERGHH, DF, M) covers 1998-01-01 to 2025-09-30 (on 7 November 2024 the start was extended from June 2000 back to January 1998, using GridSat-B1 IR data before June 2000). Early and Late (GPM_3IMERGHHE, HHL, DE, DL) also run from 1998-01-01 to the present; when checked on 2026-10-12 the latest GES DISC file was for 2026-10-11. There are no Final data from October 2025 onward until V08 Final is released.

Overview¶

IMERG is NASA's multi-satellite precipitation product, combining information from the GPM satellite constellation: passive microwave (PMW) precipitation estimates are intercalibrated to the GPM Core Observatory combined radar–radiometer product (CORRA), and gaps are filled by morphing the microwave estimates along the motion of rain systems and by geostationary IR estimates in a Kalman filter, giving global half-hourly 0.1° precipitation. It comes as near-real-time Early (~4 hours after observation) and Late (~14 hours) Runs, and a research-grade Final Run calibrated to monthly gauge analyses and released about 4 months later. V07 reprocesses the whole record from 1998, including the TRMM era, and supersedes all prior IMERG versions as well as the TRMM-based TMPA products (3B42, 3B43).

What changes with the successor¶

IMERG V06 → IMERG V07¶

Transition: 2023-07

The input microwave algorithm (GPROF2021) and the calibration scheme changed throughout, precipitation over snow- and ice-covered surfaces and the polar regions was filled in for the first time, and the record was extended back to January 1998. Key variable names also changed (precipitationCal → precipitation), so code written for V06 needs updating.

Sources: IMERG V07 Release Notes (2024-11-26) · Status of IMERG Version 06 and 07 Data (GPM, 2024-06-21) · GES DISC GPM_3IMERGDF V07 collection description

IMERG V07 → IMERG V08 Planned¶

Transition: 2026

With the parent products (GPROF, CORRA) moving to V08, V07 Final stopped at September 2025. V08 Final, reprocessed from 1998, is expected in fall 2026, and V08 Early and Late after that (no sooner than winter 2026). When checked on 2026-10-12, no V08 IMERG collection was yet registered in NASA CMR.

Sources: Update to the IMERG V08 Transition Schedule (GPM, 2026-08-06) · IMERG V08 Transition Schedule (GPM, 2026-04-28) · GPM Version 08 Reprocessing (Earthdata alert)

Available variables¶

Main variables from the GES DISC V07 collection metadata. In the half-hourly and monthly files (HDF5) they sit in the Grid group (auxiliary variables in Grid/Intermediate); in the daily files (netCDF4) they are at the top level. Arrays are ordered (time, lon, lat), so swap axes before plotting maps. precipitation is the recommended variable for most users.

instantaneous mean accumulated maximum minimum static — instantaneous: value at the time stamp · mean/accumulated/maximum/minimum: over the indicated interval · static: does not change with time

Half-hourly (GPM_3IMERGHH Final / HHE Early / HHL Late)¶

Daily (GPM_3IMERGDF Final / DE Early / DL Late)¶

Monthly (GPM_3IMERGM, Final only)¶

Static fields¶

The full variable list is in the official documentation.

How to get the data¶

• NASA GES DISC (Earthdata Cloud, HTTPS) — HTTPS download / earthaccess / Earthdata Search / subsetting
  • Final is GPM_3IMERGHH (half-hourly), GPM_3IMERGDF (daily) and GPM_3IMERGM (monthly); Early is GPM_3IMERGHHE and GPM_3IMERGDE; Late is GPM_3IMERGHHL and GPM_3IMERGDL. Files are at https://data.gesdisc.earthdata.nasa.gov/data/GPM_L3/GPM_3IMERGDF.07/YYYY/MM/ and require a free Earthdata Login. The legacy server (gpm1.gesdisc.eosdis.nasa.gov) may close any time after 30 September 2026, so update the URLs in your scripts.
• Earthdata Cloud OPeNDAP — OPeNDAP (Hyrax) — variable and spatial subsetting
  • Per-file OPeNDAP URLs are listed in CMR and Earthdata Search results. The GES DISC GrADS Data Server (GDS) is being discontinued from March 2026.
• Direct access in AWS us-west-2 (S3) — Cloud storage (S3, from within us-west-2 only)
  • Stored under paths such as s3://gesdisc-cumulus-prod-protected/GPM_L3/GPM_3IMERGHH.07/; temporary credentials are required.
• NASA PPS (GPM data directory) — HTTPS / FTP (PPS registration required)
  • The fastest place to get new data. Early and Late GeoTIFF (GIS) files and the 3-hour and 7-day files are also here.
• NASA Giovanni — Web maps and time-series analysis
  • Handy for checking magnitudes with area-mean time series or maps before downloading.

Example code¶

Downloads Final daily data for the Korean Peninsula for July 2023 with earthaccess and opens them with xarray. You will be asked for your Earthdata username and password on the first run. Daily files are ordered (time, lon, lat), so transpose before plotting maps.

import earthaccess
import xarray as xr

earthaccess.login()  # free NASA Earthdata account
results = earthaccess.search_data(
    short_name="GPM_3IMERGDF", version="07",
    temporal=("2023-07-01", "2023-07-31"),
    bounding_box=(124, 33, 132, 39),   # (west, south, east, north)
)
files = earthaccess.download(results, "imerg_daily")

ds = xr.open_mfdataset(files, combine="by_coords")
pr = ds["precipitation"].sel(lon=slice(124, 132), lat=slice(33, 39))   # mm/day, 00–24 UTC
pr = pr.transpose("time", "lat", "lon")
print(pr.mean("time"))

# Half-hourly files (HDF5) need the group: xr.open_dataset(f, group="Grid")
# Half-hour amount (mm) = precipitation (mm/hr) * 0.5

Practical tips¶

• Half-hourly precipitation is a rate in mm/hr. Adding 48 half-hourly files as they are gives twice the daily total. Convert half-hourly values with × 0.5 and monthly values (mm/hr) with × the hours in the month.
• Early, Late and Final differ in algorithm (forward-only vs forward-and-backward morphing) and calibration (climatological vs monthly gauge), so treat them as different datasets. Use Final for long-term work, and if you append recent months from the Late Run, say so in your paper.
• There are no Final data after September 2025. When V08 Final arrives, the whole record from 1998 will change, so do not mix V07 and V08 — download the full period again.
• V07C in Early and Late file names (from 2026-03-04) is the hybrid run: V07 algorithm with GPROF V08 input. Its inputs differ from the earlier V07B period, so small discontinuities are possible.
• V07 is the first version to include microwave estimates over snow- and ice-covered surfaces, but these polar estimates have lower confidence, and NASA notes that snowfall amounts are deficient. Uncertainty is also large over mountainous terrain.
• Data before June 2000 (1998-01 to 2000-05) are built from GridSat-B1 IR data; the release notes warn of lower quality and inconsistencies and recommend avoiding this period unless necessary. Also read the caveats document for the TRMM era (before 2014).
• The daily data day is 00–24 UTC. Align day boundaries when comparing with station observations reported for local-time days.
• Half-hourly and monthly files are HDF5; daily files are netCDF4. Arrays are stored as (lon, lat), so plotting them directly rotates the map by 90°.

Notices and change history¶

References for your paper¶

Dataset citation¶

IMERG Final half-hourly V07 (GES DISC) — DOI 10.5067/GPM/IMERG/3B-HH/07

@misc{imerg_v07_hh,
  author    = {Huffman, G. J. and Stocker, E. F. and Bolvin, D. T. and Nelkin, E. J. and Tan, Jackson},
  title     = {{GPM IMERG} Final Precipitation {L3} Half Hourly 0.1 degree x 0.1 degree {V07}},
  year      = {2023},
  publisher = {Goddard Earth Sciences Data and Information Services Center (GES DISC)},
  address   = {Greenbelt, MD},
  doi       = {10.5067/GPM/IMERG/3B-HH/07}
}

IMERG Final daily V07 (GES DISC) — DOI 10.5067/GPM/IMERGDF/DAY/07

@misc{imerg_v07_day,
  author    = {Huffman, G. J. and Stocker, E. F. and Bolvin, D. T. and Nelkin, E. J. and Tan, Jackson},
  editor    = {Savtchenko, Andrey},
  title     = {{GPM IMERG} Final Precipitation {L3} 1 day 0.1 degree x 0.1 degree {V07}},
  year      = {2023},
  publisher = {Goddard Earth Sciences Data and Information Services Center (GES DISC)},
  address   = {Greenbelt, MD},
  doi       = {10.5067/GPM/IMERGDF/DAY/07}
}

IMERG Final monthly V07 (GES DISC) — DOI 10.5067/GPM/IMERG/3B-MONTH/07

@misc{imerg_v07_month,
  author    = {Huffman, G. J. and Stocker, E. F. and Bolvin, D. T. and Nelkin, E. J. and Tan, Jackson},
  title     = {{GPM IMERG} Final Precipitation {L3} 1 month 0.1 degree x 0.1 degree {V07}},
  year      = {2023},
  publisher = {Goddard Earth Sciences Data and Information Services Center (GES DISC)},
  address   = {Greenbelt, MD},
  doi       = {10.5067/GPM/IMERG/3B-MONTH/07}
}

Reference papers¶

IMERG overview (chapter in Satellite Precipitation Measurement) — DOI 10.1007/978-3-030-24568-9_19

@incollection{huffman2020imerg,
  author    = {Huffman, George J. and Bolvin, David T. and Braithwaite, Dan and Hsu, Kuo-Lin and Joyce, Robert J. and Kidd, Christopher and Nelkin, Eric J. and Sorooshian, Soroosh and Stocker, Erich F. and Tan, Jackson and Wolff, David B. and Xie, Pingping},
  title     = {Integrated Multi-satellite Retrievals for the Global Precipitation Measurement ({GPM}) Mission ({IMERG})},
  booktitle = {Satellite Precipitation Measurement},
  series    = {Advances in Global Change Research},
  publisher = {Springer International Publishing},
  address   = {Cham},
  pages     = {343--353},
  year      = {2020},
  doi       = {10.1007/978-3-030-24568-9_19}
}

IMERG V07 Algorithm Theoretical Basis Document (ATBD) — no DOI

@techreport{huffman2023imergatbd,
  author      = {Huffman, George J. and Bolvin, David T. and Joyce, Robert and Nelkin, Eric J. and Tan, Jackson and Braithwaite, Dan and Hsu, Kuolin and Kelley, Owen A. and Nguyen, Phu and Sorooshian, Soroosh and Watters, Daniel C. and West, Brandon J. and Xie, Pingping},
  title       = {Integrated Multi-satellitE Retrievals for {GPM} ({IMERG}) Algorithm Theoretical Basis Document ({ATBD}), Version 07},
  institution = {NASA Goddard Space Flight Center},
  year        = {2023},
  url         = {https://gpm.nasa.gov/sites/default/files/2023-07/IMERG_V07_ATBD_final_230712.pdf}
}

Acknowledgements¶

Cite the GES DISC dataset DOI that matches the product you used (half-hourly, daily or monthly; Early, Late or Final). The half-hourly Early and Late DOIs are 10.5067/GPM/IMERG/3B-HH-E/07 (Early) and 10.5067/GPM/IMERG/3B-HH-L/07 (Late). For the algorithm, cite Huffman et al. (2020) together with the V07 ATBD.

Information on the datasets used in this study was compiled with the help of the Korean Climate Data Navigator (KCDN) (Sim, 2026; https://doi.org/10.5281/zenodo.23300923).

Links¶

• GPM IMERG overview page
• IMERG V07 Release Notes
• IMERG V07 ATBD (2023-07-12)
• IMERG V08 Transition Schedule (2026-04-28, updated 2026-08-06)
• GES DISC GPM_3IMERGHH V07
• GES DISC GPM_3IMERGDF V07
• GES DISC GPM_3IMERGM V07
• IMERG TRMM-era data caveats (GES DISC)
• Earthdata Forum — interpreting half-hourly units (mm/hr)