Satellite data for urban heat mapping in Australian cities
By Mazdak Ghasemi · Last checked 22 October 2026
Which satellite data is best for mapping urban heat islands in Australia?
Thermal infrared imagery that measures land surface temperature: how hot the ground would feel to touch, which NASA notes is not the air temperature in the weather report. Landsat 8 and 9 are the free standard; their thermal bands are collected at 100 m and delivered resampled to 30 m, and NSW's Sydney urban heat island data was derived from Landsat 8. ECOSTRESS adds 70 m data at different times of day.
Which data to use
| Data | Resolution | Revisit | Record | Use |
|---|---|---|---|---|
| Landsat 8 and 9 thermal bands | 100 m, delivered at 30 m | 16 days each, 8 together | From 2013 | Daytime land surface temperature |
| ECOSTRESS | 70 m | Every 3 to 5 days, at different times of day | From July 2018 | Heat through the day, between 52° N and 52° S |
| ASTER thermal archive | 90 m | Archive | 2000 to 16 January 2026 | Earlier summers; the instrument is now switched off |
| Landsat Collection 2 Surface Temperature | 30 m product | With each Landsat scene | Landsat 4 to 9 | Ready-made surface temperature in kelvin |
How it is done
- Choose clear daytime scenes from hot periods.
- Use the Landsat Collection 2 Surface Temperature product rather than raw thermal bands.
- Compare urban areas with a non-urban, vegetated reference, as NSW's urban heat island data does, and relate the pattern to land cover and vegetation.
Limits to know
- Land surface temperature is not air temperature, so it does not show directly how hot people feel.
- Landsat passes in the morning, so it misses the afternoon peak and night-time heat; ECOSTRESS samples other times of day.
- Thermal detail is coarser than the 30 m delivery suggests, because it is collected at 100 m.
- USGS notes the Surface Temperature product has missing data where its emissivity input (ASTER GED) is missing.
- ASTER's thermal instrument was permanently turned off on 16 January 2026, so it cannot measure a current summer.
Who does this in practice
- NSW's urban heat island data for Greater Sydney was derived from Landsat 8 land surface temperature for the summer of 2015–16, measured against a non-urban vegetated reference.
- Victoria's Metropolitan Melbourne Urban Heat Islands and Urban Vegetation dataset is derived from Landsat 8 land surface temperature.
What Terrascout returns
The real result for “Map urban heat islands across Western Sydney NSW in summer” (Sydney, NSW), captured on 22 October 2026: the top 2 of 5 sources.
| # | Source | Type | Resolution | Cost | Fit |
|---|---|---|---|---|---|
| 1 | Landsat 8 OLI/TIRS | Optical | 30 m | No data fee | 98 |
| 2 | Landsat 9 OLI-2/TIRS-2 | Optical | 30 m | No data fee | 98 |