Slope angle map of Finland, Sweden and Norway

What the slope angle map shows

Hylly Slope is a slope angle map of Finland, Sweden and mainland Norway. It computes how steep the ground is from the official elevation model of each country, on a 2 m grid, and draws six classes from 20° upwards over a topographic map. In Norway this map type is also called a steepness map. It is free, needs no account and works in a phone browser.

To find a place, type its official name with the local spelling, for example Saana, Kebnekaise or Tromsø, or pan and zoom. "My location" centres the map on your position once. "Copy map link" copies a link to the exact view, ready to send to a trip partner.

The colours show at every zoom level. Each class has one fixed colour:

• 20–24° blue
• 25–29° light green
• 30–34° yellow
• 35–39° orange
• 40–44° red
• ≥45° magenta

How do I read the slope angle colours?

Slope angle is the angle of the ground surface in its steepest direction, in degrees. The colours start at 20°. Terrain with no colour is below 20° or a gap in the source data; the map cannot tell these apart, so uncoloured does not mean flat or safe.

There are no point values: compare the colour with the legend. Class limits are approximate, because values are stored in 2° steps; a slope just over 25° can still show in the 20–24° class.

Zoomed out, each pixel shows the steepest value in the area it covers, so steep classes look larger than they do at close zoom. Zoom in before you judge a single slope.

Degrees and percent

The map and its legend use degrees. Percent is the rise divided by the horizontal distance, times 100, and the two scales do not grow at the same rate: 45° is 100%, 30° is about 58% and 20° is about 36%.

Coverage and data: Finland, Sweden and mainland Norway on a 2 m grid

The slope layer covers Finland, Sweden and mainland Norway, but not Svalbard or Jan Mayen. The sources are the Maanmittauslaitos Korkeusmalli 2 m (Finland), the Lantmäteriet Markhöjdmodell 1 m (Sweden) and the Kartverket DTM 1 (Norway). The Swedish and Norwegian 1 m models are averaged to 2 m before the slope is computed.

Grid size is not accuracy: a 2 m cell is the raster spacing, not the exact surface of a rock, a cliff, snow or a tree. Where the source model has a real gap, the map stays transparent rather than filling the hole with coarser data.

Full method: Data and method.

Area pages

Eleven places have their own page: seven in the fells of Finland (fells are the open, treeless hills of the north), Abisko in the Swedish mountains and three in the mountains of northern Norway. Each page has local terrain notes, a link to the official avalanche forecast for that area and a direct map link. The map covers far more ground than these eleven places.

• Levi

  A 530 m fell, mostly uncoloured on the map; Pahtakuru gorge on Kätkätunturi has the most colour and 35–39° in short sections.

• Ylläs

  Yllästunturi shows little colour on the map; the largest shares of 30° and steeper are at Pirunkuru and on Kellostapuli.

• Pallas

  On the map, the most 30° and steeper terrain is in the Pyhäkuru gorge and on the east sides of Lehmäkero and Pyhäkero.

• Pyhä-Luosto

  In the Isokuru gorge more than half the terrain is 30° or steeper on the map; the Pyhätunturi tops are mostly uncoloured.

• Ruka

  Rukatunturi and the Valtavaara ridge; the most 30° and steeper terrain is in Surmanoro and at the Juhannuskallio cliff.

• Saariselkä

  Low, rounded fells with almost no colour on the map; the steepest classes are in the Rumakuru and Pääsiäiskuru gorges.

• Kilpisjärvi

  Around Saana, all six classes appear, the steepest mainly on the west and north; the Malla fells are mostly uncoloured.

• Abisko

  Near Abisko, Nuolja's north and east sides are steepest on the map; the village and valley floor are nearly uncoloured.

• Lyngen

  Alpine peaks rising from sea level; around the highest summits more than half of the terrain is 30° or steeper on the map.

• Tromsø

  Fløya by the city is mostly uncoloured; around Store Blåmannen on Kvaløya about a quarter is in the 45° and steeper class.

• Narvik

  The Narvikfjellet ski area sits directly above the town; about half of the terrain around it is 30° or steeper on the map.

Slope angle and avalanche terrain

Slope angle is one terrain factor in ski touring, backcountry skiing and winter hiking. The map does not show runout zones, slope aspect, snow or current conditions. Lavinprognoser.se, the Swedish avalanche forecast service, warns that avalanches can reach flatter terrain below steep slopes, so uncoloured ground below a steep slope can lie in the path of an avalanche.

Hylly Slope is a planning aid, not an avalanche forecast or a safety assessment. Check the official forecast for your area:

• Finnish Meteorological Institute: avalanche forecast (Finland)
• Lavinprognoser.se: avalanche forecast (Sweden)
• Varsom: avalanche forecast (Norway)

Hylly.org maps

Hylly Slope is one of the Hylly.org maps.

• All Hylly.org maps