About CoolingSpots
CoolingSpots shows for free where it is cool or shady in the heat: forest, swimming spots, gorges, waterfalls, caves, mountains with hiking trails. No account, no sign-up.
The motivation behind this project
Hot days will become more frequent. Alongside climate protection, heat protection matters at least as much for people - and that includes informing them where to find relief.
On long hot days the walls can close in, or a flat simply does not stay cool. The dog still needs walking, children want a change of scene. And sometimes what is missing is simply inspiration for the summer holidays or a weekend: the next lakeside swimming spot, a museum nearby, a cave to explore.
The focus is deliberately on natural places - forest, water, gorge, high ground. Cool buildings such as museums or libraries are added as refuges, but the core is places where you actually want to spend time.
Principles of this site
- Honest rather than impressive: coolness is grouped into levels, not degrees. An exact temperature would be a promise that cannot be kept.
- Free: for every visitor, and equally for municipalities and cantons that embed the map or use it as inspiration. No account, no login.
- Data minimisation and privacy by default: your location is never stored or passed on.
- All data comes from open sources (ESA WorldCover, Copernicus, OpenStreetMap, swisstopo) and is visibly attributed - details under "Licences and sources".
Methodology: where the coolness level comes from
Reading the map
- The cooler a place, the bigger and darker its marker - the three levels match the legend.
- The symbol in the marker shows the type of place: conifer for forest, broadleaf trees for park, waves for swimming spots and pools, plus dedicated symbols for waterfall, gorge, cave, highland (mountain) and cemetery (flower).
Tapping a marker opens the details with the coolness reasons - including directions and sharing.
How coolness is calculated
The coolness level comes from real map and satellite data. This is what makes a place cool:
Shade: canopy or terrain shade blocks the sun - a dense leaf canopy (crown density from satellite data) or a deeply incised, north-facing site count the same. Water: being close to a stream or lake cools the air. Terrain: higher ground is cooler. Glacier: nearby ice brings cold air. Built-up: lots of built surfaces around store heat and subtract.
You get a clear coolness level from pleasant to distinctly cool, along with the reasons behind it.
Details: formula, data sources and limits
The score is arithmetic on open data: counting pixels, computing distances and angles. No trained model. Caves are the exception.
- Scored places: forests, parks, cemeteries, swimming spots, waterfalls, gorges, caves and highlands from OpenStreetMap. Areas count from 5 ha, cemeteries from 2 ha, each as one point. A forest or park only appears with evidence of coolness: tree canopy from 40%, terrain shade, water in immediate proximity, a nearby glacier, or an elevation from 2000 m. Swimming spots and caves always appear.
- Tree canopy: ESA WorldCover, a free land-cover map in which every 10 m pixel carries a class (tree, grass, cropland, built-up). Tree pixels are counted in a window of 21 by 21 pixels around the place: 380 out of 441 gives a canopy of 0.86. The grid is defined in degrees; in Switzerland the window measures about 195 m north-south and 133 m east-west.
- Water: distance to the nearest stream or lake (OpenStreetMap), searched up to 500 m. The effect halves roughly every 100 m.
- Terrain: elevation from the Copernicus elevation model. The value rises linearly from 300 m and is full from 1500 m. Air cools by about 6.5 degrees per 1000 m of elevation.
- Built-up area: share of residential, commercial and industrial land (OpenStreetMap) within 200 m. Built-up surfaces store heat and lower the score.
- Terrain shade: if a place lies markedly lower than its surroundings (eight directions within a 500 m radius, from the elevation model) or on a north-facing slope, that counts towards the same shade factor as tree canopy. Treeless places such as gorges and north slopes thus reach a coolness level.
- Glacier: ice less than 2 km away adds up to 10%, decreasing with distance.
- Caves: a fixed value instead of a measurement. Cave air takes on the temperature of the rock, and the rock carries the annual mean of the surface inwards - independent of tree canopy and built-up area, the quantities measured here. Caves therefore receive level 3. Limits: at the entrance the temperature varies with the weather, and the level depends on elevation. A cave at 2000 m is colder than one in the lowlands.
Score = 40% shade + 30% water + 20% terrain - 20% built-up, plus a glacier bonus of up to 10%. Shade means tree canopy or terrain shade; both count towards the same factor. Levels follow fixed thresholds: from 66 out of 100 level 3, from 48 level 2, below that level 1. Fixed thresholds mean a level says the same thing everywhere, including the lowlands. The badge "Cooler than its surroundings" marks places cooler than most within roughly 12 km.
Limits: the levels are an ordinal comparison, not a thermometer, so no degree values are given. Places near a threshold can fall on either side. The value describes the typical, naturally occurring coolness of an area from static data, not the shade at a given hour. The surroundings are measured in a window of roughly 130 to 200 m, so the statement is regional rather than street-level. Above the tree line, sparse mountain forest can be overestimated. Intermittent and seasonal watercourses are excluded, because small streams carry little water in dry periods. A narrow gorge is shaded by day but traps heat at night - daytime coolness is what is meant.