# MODIS Land Surface Temperature and Emissivity (MOD21)
*data products*

## Specifications
- **level**: L2
- **distributor**: nasa
- **spectral range nm**: {"min":8400,"max":12270}
- **spectral band count**: 3
- **gsd m**: {"native":1000}
- **file format**: HDF
- **access endpoint**: https://search.earthdata.nasa.gov/search?q=MOD21
- **access model**: open
- **licence**: NASA EOSDIS open data
- **primary data portal url**: https://modis.gsfc.nasa.gov/data/dataprod/mod21.php
- **use cases**: ["Regional land-surface temperature and emissivity","Thermal context and screening","Arid and semi-arid surface temperature retrieval"]
- **practical limitations**: ["1 km spatial resolution is coarse for building-scale thermal performance; use only as city or regional thermal context"]
- **deployment context**: orbital
- **entity type**: data_product
- **last verified date**: 2026-06-14
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **provider**: nasa
- **attributes**: {"level":"L2","distributor":"nasa","spectral_range_nm":"{\"min\":8400,\"max\":12270}","spectral_band_count":3,"gsd_m":"{\"native\":1000}","file_format":"HDF","access_endpoint":"https://search.earthdata.nasa.gov/search?q=MOD21","access_model":"open","licence":"NASA EOSDIS open data","primary_data_portal_url":"https://modis.gsfc.nasa.gov/data/dataprod/mod21.php","use_cases":"[\"Regional land-surface temperature and emissivity\",\"Thermal context and screening\",\"Arid and semi-arid surface temperature retrieval\"]","practical_limitations":"[\"1 km spatial resolution is coarse for building-scale thermal performance; use only as city or regional thermal context\"]","deployment_context":"orbital"}
- **relevance**: in-scope

## Editorial
MODIS Land Surface Temperature and Emissivity (MOD21) is an open NASA Level 2 product for land surface temperature and emissivity retrieval from MODIS thermal infrared observations [^nasa-mod21]. The product uses three thermal infrared bands spanning 8400 to 12270 nm and is distributed as HDF at 1 km native ground sampling distance [^nasa-mod21]. NASA Earthdata and the MODIS product catalogue provide access paths for MOD21 data discovery and download [^nasa-mod21].

MOD21 fits workflows that need regional land-surface temperature context, thermal screening, or arid and semi-arid surface-temperature retrieval rather than building-scale detail [^nasa-mod21]. Its 1 km spatial resolution is too coarse for direct building thermal performance assessment, but it can support city, regional, and background thermal context layers around higher-resolution observations [^nasa-mod21]. The product is an orbital, open-access data source under NASA EOSDIS open data terms [^nasa-mod21].

## Compositional position
- building-thermal (topics) --[topic_capabilities]--> MODIS Land Surface Temperature and Emissivity (MOD21)

## Sources
- [nasa-mod21] | MODIS Land Surface Temperature and Emissivity (MOD21), NASA GSFC | https://modis.gsfc.nasa.gov/data/dataprod/mod21.php | tier=agency-doc | accessed=2026-06-14

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Source: https://eo-atlas.org/data_products/modis-land-surface-temperature-emissivity
Maintainer: SpectraWorks B.V. (CC-BY 4.0)