=== versions === python 3.12.0 | pystac-client 0.9.0 | planetary-computer 1.0.0 | rasterio 1.5.2 | osmnx 2.1.1 | numpy 2.5.4 | pandas 3.0.6 === STAC search: clear Landsat 8/9 scenes over London, summer 2022 === 2022-07-10 10:52 UTC landsat-8 path/row 201/024 cloud 1.47% 2022-07-10 10:53 UTC landsat-8 path/row 201/025 cloud 0.52% 2022-07-11 10:46 UTC landsat-9 path/row 200/024 cloud 0.93% 2022-07-11 10:46 UTC landsat-9 path/row 200/025 cloud 0.02% 2022-07-18 10:52 UTC landsat-9 path/row 201/024 cloud 0.72% 2022-07-18 10:52 UTC landsat-9 path/row 201/025 cloud 5.60% 2022-08-10 10:58 UTC landsat-9 path/row 202/024 cloud 0.03% 2022-08-11 10:52 UTC landsat-8 path/row 201/024 cloud 0.01% 2022-08-12 10:46 UTC landsat-9 path/row 200/024 cloud 0.02% 2022-08-12 10:46 UTC landsat-9 path/row 200/025 cloud 0.01% using LC09_L2SP_201024_20220718_02_T1: 18 July 2022 10:52 UTC, sun elevation 56.2 deg, EPSG:32631 ST_B10 (asset 'lwir11'): scale 0.00341802, offset 149, unit kelvin, nodata 0 === surface temperature === grid 3812 x 2753 pixels of 30 m (114 x 83 km) DN 39298..54444 -> 283.3..335.1 K -> 10.2..61.9 degC QA_PIXEL bit 0 (fill): 1.73% QA_PIXEL bit 1 (dilated cloud): 0.05% QA_PIXEL bit 2 (cirrus): 0.00% QA_PIXEL bit 3 (cloud): 0.04% QA_PIXEL bit 4 (cloud shadow): 0.10% QA_PIXEL bit 5 (snow): 0.00% QA_PIXEL bit 6 (clear): 98.19% QA_PIXEL bit 7 (water): 1.08% usable land pixels: 96.6% | ST_QA uncertainty over land: median 2.06 K, 95th pct 2.94 K === LST by land cover inside Greater London (ESA WorldCover 2021) === land cover km2 median_C p10_C p90_C median_NDVI Built-up 709.2 45.84 43.53 47.73 0.33 Grassland 280.6 44.24 40.84 47.38 0.48 Tree cover 529.5 43.31 38.71 46.00 0.60 Cropland 39.5 42.49 39.98 45.99 0.33 Water 12.2 36.17 30.93 40.32 0.29 === surface urban heat island === urban: built-up pixels in Greater London, 709 km2, median LST 45.8 C rural: grass/cropland > 5 km outside London with < 5% built-up within 1 km, 2,702 km2, median LST 40.8 C surface urban heat island intensity (median urban - median rural): 5.1 C all land within 5 km of Charing Cross: median LST 45.0 C LST by NDVI band inside Greater London: ndvi_from n median_C bin 1 -0.1 235 39.09 2 0.0 29871 45.71 3 0.1 106285 46.28 4 0.2 220600 46.38 5 0.3 381107 45.81 6 0.4 369689 45.00 7 0.5 279661 43.98 8 0.6 175329 42.71 9 0.7 109904 41.00 10 0.8 74389 38.45 linear fit: LST = 48.5 -9.4 x NDVI (r = -0.61, -0.9 C per 0.1 NDVI) === west-east transect along 51.507 N === transect length 114 km; Greater London boundary crossed at -25.1, +25.5 km rural west (Berkshire) -60 to -40 km: median LST 42.1 C, NDVI 0.50 central London -5 to +5 km: median LST 43.0 C, NDVI 0.24 rural east (Essex) +40 to +60 km: median LST 43.2 C, NDVI 0.35 === hotspots (top 2% of Greater London land pixels) === threshold 48.6 C; 1,138 patches, 160 of at least 5 ha rank area_ha max_C mean_C place borough near built_% grass_% tree_% NDVI 1 88.1 51.6 49.1 Upton Newham Chaucer Road 99 0 1 0.23 2 85.7 50.1 49.0 Seven Kings Redbridge Ilford Lane 96 1 2 0.24 3 54.0 51.7 49.8 Blackheath Lewisham Prince Charles Road 1 98 0 0.31 4 54.0 54.0 50.1 South Hornchurch Havering Ford Lane 21 74 4 0.33 5 44.6 52.2 49.6 Manor Park Newham Capel Road 0 97 3 0.36 6 44.6 55.7 49.8 Becontree Heath Barking and Dagenham 39 61 0 0.29 7 42.9 54.9 49.8 Scrattons Farm Barking and Dagenham Goresbrook Road 56 38 6 0.26 8 34.7 49.8 49.1 Seven Kings Redbridge Pembroke Road 96 2 2 0.27 9 34.1 51.2 49.5 Dagenham Barking and Dagenham Manchester Way 56 44 1 0.24 10 33.8 57.8 51.5 Scrattons Farm Barking and Dagenham Ford Dagenham 99 0 1 0.11 ten largest hotspots together: 517 ha, 60% built-up, 38% grass or crops, 2% trees (WorldCover) OpenStreetMap features in the 8 x 6 km box around hotspot 1: 4,137 OSM tag km2 median LST share of hotspot pixels landuse=residential 21.10 47.4 C 38% landuse=industrial 1.71 45.8 C 2% landuse=commercial 1.00 46.8 C 2% landuse=retail 1.71 47.8 C 8% leisure=park 6.28 45.5 C 13% leisure=golf_course 0.61 43.3 C 0% === LST against air temperature at weather stations (Meteostat hourly, 11:00 UTC) === station air_10UTC_C air_11UTC_C LST_median_1km_C LST_grass_median_C LST_minus_air Heathrow 31.3 33.7 46.5 46.2 12.8 Northolt 31.8 33.3 46.2 45.9 12.9 Kenley 29.4 31.2 38.5 40.4 7.3 Biggin Hill 30.0 32.0 42.6 43.2 10.6 === outputs === 01-true-colour-lst.png 1525 KB 02-lst-landcover-ndvi.png 173 KB 03-urban-rural-transect.png 213 KB 04-hotspots-osm.png 1960 KB 05-lst-vs-air-temperature.png 30 KB hotspots.csv 1 KB lst_by_landcover.csv 0 KB lst_london_2022-07-18.tif 27326 KB