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. Getting there: as soon as you share your position, the place sheet shows the straight-line distance, the direction and - from 100 metres of difference upwards - how much higher or lower the place lies. Straight line means: the real route is always longer. We do not show travel times, because we do not compute routes.
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.