Open data
Data sources
Every number on this site comes from a public dataset. This page lists them, what they cover and the licence they are used under.
| Source | Dataset | Period | Licence | Attribution |
|---|---|---|---|---|
| EOX Sentinel-2 cloudless 2016 | s2cloudless 2016 (2017 where 2016 is missing) | 2016-2017 | CC BY 4.0 | Satellite images: Sentinel-2 cloudless 2016 by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016), CC BY 4.0 |
| GeoNames | cities1000 (towns with 1,000+ people) and countryInfo | Creative Commons Attribution 4.0 | Towns: GeoNames (CC BY 4.0) | |
| HydroLAKES | HydroLAKES v1.0 - polygons and pour points of 1.4 million lakes | Creative Commons Attribution 4.0 | Lake outlines, area and depth: HydroLAKES (Messager et al. 2016), CC BY 4.0 | |
| LakeTEMP | LakeTEMP v1 - Aggregated (monthly lake surface temperature, ice) | 2013-2021 (Landsat 8) | Creative Commons Attribution 4.0 | Water temperature and ice: LakeTEMP (Korver et al. 2024), CC BY 4.0 |
| NASA POWER | Climatology, monthly and daily point data (MERRA-2 / CERES SYN1deg) | 1991-2020 averages; 2020-2025 month by month; daily rain 1991-2025 | US Government data - no use restrictions | Climate: NASA Langley Research Center POWER Project |
| OpenStreetMap | Beaches, bathing places, campsites, marinas, slipways, boat rental, viewpoints, lodging (Overpass API) | Open Database License (ODbL) 1.0 | Around the shore: © OpenStreetMap contributors (ODbL) | |
| OurAirports | airports.csv | Public domain | Airports: OurAirports (public domain) | |
| Wikidata | Lakes and reservoirs: names in 7 languages, short descriptions, maximum depth, images | CC0 1.0 (public domain) | Lake names: Wikidata (CC0) | |
| Wikimedia Commons | Photographs of each lake (Wikidata P18, Commons category, geosearch) | Per file: public domain, CC0, CC BY or CC BY-SA only | Photos: Wikimedia Commons, author and licence under each photo | |
| flag-icons | Country flags in SVG (4:3) | MIT | Flags: flag-icons (MIT) |
Water temperature and ice
Water temperatures come from LakeTEMP (Korver, Lehner, Cardille and Carrea, 2024, Remote Sensing of Environment 308: 114164), which measured the surface of 1.4 million lakes with the Landsat 8 satellite from 2013 to 2021, at the point of each lake furthest from any shore. We show the monthly averages only where the authors recommend them: statistics from the seasonal curve, lakes that do not dry out, and at least 46 measurements. Ice duration and the usual freeze and thaw dates come from the same dataset.
Climate on the shore
Air temperature, rain, humidity, wind and solar radiation come from NASA POWER (averages for 1991–2020, about 55 km resolution). The data was obtained from NASA Langley Research Center's POWER project funded through the NASA Earth Science Division. Highs and lows are derived from the mean temperature and the mean daily range. A rainy day has at least 1 mm of rain (the World Meteorological Organization definition), counted from daily data. Sunshine hours are derived from measured solar radiation with the Ångström–Prescott relation.
Lakes, outlines and names
Outlines, area, average depth, volume, shoreline, residence time and elevation come from HydroLAKES (Messager et al., 2016, Nature Communications 7: 13603). Names in every language, short descriptions, maximum depth and the main photo come from Wikidata (CC0). A name is matched to an outline when its coordinates fall inside the lake, or within 1 km of its shore.
Around the shore
Beaches, campsites, marinas, boat hire, ferry piers, viewpoints, lodging and restaurants within 1.5 km of the shoreline are counted from OpenStreetMap (© OpenStreetMap contributors, ODbL). Towns come from GeoNames (CC BY 4.0) and airports from OurAirports (public domain).
Images
Satellite images are the Sentinel-2 cloudless 2016 mosaic by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016), CC BY 4.0, slightly sharpened. Photos come from Wikimedia Commons, only under licences that allow reuse (public domain, CC0, CC BY, CC BY-SA), with the author and licence under each one.
