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Full catalog/VJ121C3
VJ121C3·v002·dataset

How hot the land surface gets monthly (NOAA-20, 0.05 deg)

VIIRS/JPSS1 Land Surface Temperature/Emissivity Monthly L3 Global 0.05Deg CMG V002
land NASA LPCLOUD Level 3 active HDF-EOS5
In plain English

What it measures. Monthly maps of how hot the land surface gets (day and night) and how efficiently surfaces radiate heat (emissivity), at about 5.6 km resolution.

How it's made. Built by the VIIRS instrument on the NOAA-20 satellite by picking the best cloud-free pixels over each month and averaging the daily readings.

How & where you'd use it. Formatted for use in climate models; also useful for studying urban heat, droughts, and seasonal surface-temperature patterns.

What's measured

LAND SURFACE › SURFACE RADIATIVE PROPERTIES › EMISSIVITYLAND SURFACE › SURFACE THERMAL PROPERTIES › LAND SURFACE TEMPERATURE

Coverage & cadence

  • Time span2018-01-01 → ongoing
  • Measured byNOAA-20 (VIIRS)
  • Processing levelLevel 3
  • Spatial extent-180, -90, 180, 90
  • FormatsHDF-EOS5
  • StatusACTIVE

What you can do with it

  • Track deforestation, fire scars and land-cover change
  • Monitor crop and vegetation health (NDVI/EVI)
  • Map how built-up vs. green an area is over time
Official description

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) monthly Climate Modeling Grid Version 2 product (VJ121C3) provides LST&E by a process of selecting the best available pixel over a monthly acquisition period at 0.05 degree (~5,600 meter) resolution. The VJ121C3 dataset is a monthly composite LST&E product that uses an algorithm based on a simple averaging method and is formatted as a CMG for use in climate simulation models. The algorithm calculates the average from all the cloud free [VJ121A1D](http://doi.org/10.5067/VIIRS/VJ121A1D.002) and [VJ121A1N](http://doi.org/10.5067/VIIRS/VJ121A1N.002) daily acquisitions from the monthly period. Unlike the VJ121A1 data sets where the daytime and nighttime acquisitions are separate products, the VJ121C3 contains both daytime and nighttime acquisitions as separate Science Dataset (SDS) variables within a single Hierarchical Data Format (HDF) file. Additional details regarding the method used to create this Level 3 (L3) product are available in the Algorithm Theoretical Basis Document (ATBD). The VJ121C3 product contains 27 Science Datasets (SDS) variables: LST, quality control, view zenith angle, and time of observation for both day and night observations along with emissivity for bands M14, M15, and M16. Low-resolution browse images for day and night LST are also available for each VJ121C3 granule. Known Issues * For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS) and the User Guide.

Get the data

vj121c3_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ121C3",
    version="002",
    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 LPCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.