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Full catalog/TRMM_3B42
TRMM_3B42·v7·dataset

How much it rained, every 3 hours (TRMM, 0.25 deg)

TRMM (TMPA) Rainfall Estimate L3 3 hour 0.25 degree x 0.25 degree V7 (TRMM_3B42) at GES DISC
atmosphere NASA GES_DISC Level 3
In plain English

What it measures. Estimates of how much rain fell across the tropics and nearby regions, reported every 3 hours on a 0.25-degree map grid.

How it's made. Produced by the TRMM mission's multi-satellite analysis, which blended high-quality microwave rainfall measurements with infrared estimates to fill gaps. Note: this product was discontinued at the end of 2019 in favor of the newer IMERG dataset.

How & where you'd use it. Used to study rainfall patterns, storms, and water cycles in tropical regions, though new users are encouraged to switch to the successor IMERG product.

What's measured

ATMOSPHERE › PRECIPITATION › TOTAL SURFACE PRECIPITATION RATE

Coverage & cadence

  • Time span1997-12-31 → 2019-12-31
  • Measured byTMPA (NOT APPLICABLE)
  • Processing levelLevel 3
  • Spatial extent-180, -50, 180, 50
  • StatusCOMPLETE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

TMPA (3B42) dataset have been discontinued as of Dec. 31, 2019, and users are strongly encouraged to shift to the successor IMERG dataset (doi: 10.5067/GPM/IMERG/3B-HH/06). This dataset was the output from the TMPA (TRMM Multi-satellite Precipitation Analysis) Algorithm. It provides precipitation estimates in the TRMM regions that have the (nearly-zero) bias of the ”TRMM Combined Instrument” precipitation estimate and the dense sampling of high-quality microwave data with fill-in using microwave-calibrated infrared estimates. The granule temporal coverage is 3 hours.

Get the data

trmm_3b42_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="TRMM_3B42",
    version="7",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from GES_DISC
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.