Earth Data School
About
Full catalog/M2SMNXEDI
M2SMNXEDI·v1·dataset

Modeled monthly weather extremes (MERRA-2)

MERRA-2 statM_2d_edi_Nx: 2d, Single-Level, Monthly Extremes Detection Indices V1 (M2SMNXEDI) at GES DISC
atmosphere NASA GES_DISC Level 4
In plain English

What it measures. Monthly summaries that flag and describe extreme weather, like heatwaves, cold spells, and stretches of unusually dry or wet days, including how often they happen, how long they last, and how intense they get. The numbers describe both temperature and precipitation extremes.

How it's made. It's computed from NASA's MERRA-2 reanalysis (a model-and-observation blend of the satellite era) by comparing each month's daily values against a long-term climate average and counting the extremes.

How & where you'd use it. Handy for spotting trends in heatwaves, cold snaps, and dry or wet spells over time, useful to climate researchers, journalists tracking weather extremes, and planners thinking about heat or drought risk.

What's measured

ATMOSPHERE › ATMOSPHERIC TEMPERATURE › SURFACE TEMPERATURE › AIR TEMPERATURECLIMATE INDICATORS › ATMOSPHERIC/OCEAN INDICATORS › EXTREME WEATHER › EXTREME DROUGHTCLIMATE INDICATORS › ATMOSPHERIC/OCEAN INDICATORS › EXTREME WEATHER › HEAT/COLD WAVE FREQUENCY/INTENSITYCLIMATE INDICATORS › ATMOSPHERIC/OCEAN INDICATORS › EXTREME WEATHER › EXTREME PRECIPITATIONATMOSPHERE › PRECIPITATION › PRECIPITATION RATE

Coverage & cadence

  • Time span1980-01-01 → 2022-12-31
  • Measured byMERRA-2 (NOT APPLICABLE)
  • Processing levelLevel 4
  • Spatial extent-180, -90, 180, 90
  • 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

M2SMNXEDI (or statM_2d_edi_Nx) is a 2-dimensional monthly data collection for extreme detection indices derived from daily Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) datasets within each month. V1, the original version of this extreme detection indices data collection, is computed based on the 1981-2010 climatology, covering the period from January 1980 to December 2022. In contrast, V2, the second version, is calculated based on a 30-year climatology (1991-2020), covering the period from January 1980 to the present. This collection consists of indices used to identify or characterize extreme weather events associated with temperature, such as heatwaves and cold spells (e.g., their frequency, duration, and intensity), as well as events associated with precipitation, such as dry days and wet days (e.g., their frequency, duration, and intensity). MERRA-2 is the latest version of global atmospheric reanalysis for the satellite era produced by the NASA Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980-present, with a latency of ~3 weeks after the end of the previous month. Data Reprocessing: Please check “Records of MERRA-2 Data Reprocessing and Service Changes”, linked from the “Documentation” tab on this page. Note that a reprocessed data filename is different from the original filename. MERRA-2 Mailing List: Sign up to receive information on reprocessing of data, changes to tools and services, as well as data announcements from GMAO. Contact the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov) to be added to the list. Questions: If you have a question, please read the "MERRA-2 File Specification Document'', “MERRA-2 Data Access – Quick Start Guide”, and FAQs linked from the ”Documentation” tab on this page for more information. If these documents do not answer your question, you may post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov).

Get the data

m2smnxedi_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2SMNXEDI",
    version="1",
    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.