Weather

‘There is no such thing as bad weather, only bad clothing’ is a pleasant claim as long as you are sitting indoors. In the mountains it is incomplete: bad weather is real, it calls for preparation, and it can become dangerous. The difference between being out in sunshine and being out in a sleet storm is not just the experience — it is your clothing, your route plan, and on some days whether the trip should go ahead at all.

How the weather forms

Weather is the result of the atmosphere and the ocean evening out the difference in energy between the equator (a surplus) and the poles (a deficit). Low pressure and high pressure are how this evening-out shows itself, and their movements give us what we call weather systems.

• Low pressure usually brings precipitation and lower temperatures. Air flows in towards the centre of the low, is pushed upwards, cools and condenses into cloud and rain.
• High pressure brings clear weather — warm in summer, cold in winter. Air sinks, warms up, and the clouds evaporate.

In Norway, lows pass from the west typically at intervals of 1-3 days, in both summer and winter. This is the dynamic we observe on the weather chart and that the meteorologists predict.

The forecast — what can you rely on?

Modern weather forecasts are built from weather-station observations and numerical mathematical models that calculate how the weather will behave. The scale of reliability:

• Within 24 hours: typically 90% accurate
• 2-3 days ahead: 70-85% accurate
• 4-7 days ahead: 50-65% — starting to become unreliable
• Over a week: trends only, not details

For trip planning, a 24-48 hour forecast is what can actually be used. Further ahead than that is only an estimate — check again before you set off.

More about weather forecasting →

The trip meteorologist

For more precise assessments of the mountains and the fjord, the trip meteorologist (turmeteorologen) is available as a service from the Norwegian Meteorological Institute. They provide location-specific forecasts for named mountains and areas, often 24-48 hours ahead. It is much used by the ski-touring, paddling and mountaineering communities.

More about the trip meteorologist →

Nature’s own weather signs

Long before the mobile phone and the Yr app, people read the weather in nature. Many of these weather signs (værtegn) still work as a 24-hour forecast:

Clouds

• Cirrus (thin, wispy feather clouds high in the sky) — often signals a change in the weather within 24-48 hours
• Cumulus (low, white ‘cauliflower clouds’) — common in fair summer weather
• Stratus (a low, even grey blanket) — overcast, often rain
• Nimbostratus (dark grey, low) — longer periods of rain
• Cumulonimbus (heavy thunderclouds) — rough weather, local precipitation, possible thunder

Wind

• A wind shift — particularly from west to south, suggests a low on its way
• A sudden calm before a storm — air masses gathering
• Snow smoke on the summits — strong wind up high, but it concerns us lower down

Pressure (if you have a barometer)

• Falling pressure = a low on its way = worse weather
• Rising pressure = a high on its way = better weather

Sound and humidity

• Echoes and sound that carries far — moisture in the air, often before rain
• Insects bite more aggressively — the humidity is rising

More about nature’s weather forecasts →

Wind and its effect

Wind is not just uncomfortable — it can be the most dangerous of the weather elements, because it dramatically changes the felt temperature and the physical strain:

Wind speed	What you notice
0-1 m/s (calm)	Still, settled conditions
2-5 m/s (light breeze)	Sounds from leaves, slight cooling
6-9 m/s (fresh breeze)	Your cap blows off, snow drift gathers
10-13 m/s (moderate gale)	Heavier movement, snow smoke
14-17 m/s (fresh gale)	Hard to walk into the wind, strong cooling
18-23 m/s (strong gale)	A real headwind, risk of falling
24+ m/s (storm)	Not suitable for a trip — seek shelter

Wind chill makes it feel much colder than the thermometer shows:

• 0 °C with 10 m/s wind = feels like −9 °C
• −10 °C with 10 m/s wind = feels like −21 °C
• −20 °C with 15 m/s wind = feels like −35 °C

For a trip in winter, the wind-chill table is central — it decides whether your clothing is sufficient.

More about wind and its effect →

Weather conditions that call for extra care

• Fog and poor visibility — a navigation challenge; the compass becomes decisive
• Severe cold — use the layering principle for your clothing, and keep moving
• Strong wind — particularly combined with wet snow or rain, it is at its most dangerous
• Rain and wind at the same time — the quickest route to hypothermia in the summer mountains
• Thunderstorms — get down off summits and ridges, and avoid isolated trees

For winter specifically: the avalanche forecast is a separate, specialist assessment — see the avalanche category and varsom.no.

Practical resources

• yr.no — the standard for forecasts in Norway, run by MET and NRK. Detailed by coordinate
• storm.no — more dynamic forecasts, including the Meteo model
• ecmwf.int/charts — European weather models, technical and advanced
• MET — the trip meteorologist — a telephone service for specific trips
• varsom.no — avalanche and flood warnings

Learn more

• Weather forecasting
• The trip meteorologist
• Wind and its effect
• Nature’s weather forecasts

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Tekst: Snuitide (2022), bearbeidet 2026.

Sentrale ressurser: yr.no · Meteorologisk institutt · Storm.no · Varsom.no