Climate and average weather in Longyearbyen
In Longyearbyen, the summers are cold, showery, and mostly cloudy and the winters are frigid, snowy, and mostly cloudy.
Over the course of the year, the temperature in Longyearbyen typically varies from -17°C to 7°C, and is rarely below -27°C or above 10°C. July is the hottest month of the year, while March is the coldest.
Based on the travel score, Longyearbyen has no standout warm-weather window — it stays modest all year, so any month is much like another for a visit.
- Hottest
- Jul
- 7°
- Coldest
- Mar
- -17°
- Wettest
- Nov
- 47 mm
- Driest
- Jun
- 18 mm
- Rain / yr
- 418 mm
- 98 wet days
- Daylight
- 0.0–24.0 h
- shortest–longest
- Elevation
- 1 m
- 78.2°N
- Clearest
- Apr
- 77% cloud
Longyearbyen is town and administrative centre in Svalbard, Norway.
- Density
- 10/km²
- people per km²
- Founded
- 1906
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Longyearbyen weather by month, at a glance
The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.
Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once.
Temperature through the year
Daily average highs and lows in Longyearbyen, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 2.9 months, from June 15 to September 11, with daily high temperatures above 2°C. The hottest month of the year in Longyearbyen is July, with an average high of 7°C and low of 4°C.
The cool season lasts 4.3 months, from December 8 to April 16, with daily high temperatures below -8°C. The coldest month of the year in Longyearbyen is March, with an average low of -17°C and high of -12°C.
Days typically run about 4°C warmer than nights year-round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | -11 | -12 | -12 | -9 | -3 | 2 | 7 | 5 | 1 | -4 | -7 | -10 |
| Avg low (°C) | -16 | -16 | -16 | -13 | -5 | 1 | 4 | 3 | -1 | -8 | -12 | -14 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | -11 | -16 |
| Feb | -12 | -16 |
| Mar | -12 | -16 |
| Apr | -9 | -13 |
| May | -3 | -5 |
| Jun | 2 | 1 |
| Jul | 7 | 4 |
| Aug | 5 | 3 |
| Sep | 1 | -1 |
| Oct | -4 | -8 |
| Nov | -7 | -12 |
| Dec | -10 | -14 |
How hot and cold Longyearbyen really feels
The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.
On the coldest nights, wind chill pulls the feels-like down to about -24°C (around February 23), with roughly 315 freezing days a year (feels-like at or below 0°C) — 219 of them bitterly cold — worst in February.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | -11 | -12 | -12 | -9 | -3 | 2 | 7 | 5 | 1 | -4 | -7 | -10 |
| Air high (°C) | -11 | -12 | -12 | -9 | -3 | 2 | 7 | 5 | 1 | -4 | -7 | -10 |
| Feels-like low (°C) | -23 | -23 | -23 | -18 | -9 | -2 | 1 | 0 | -5 | -13 | -18 | -21 |
| Air low (°C) | -16 | -16 | -16 | -13 | -5 | 1 | 4 | 3 | -1 | -8 | -12 | -14 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | -11 | -11 | -23 | -16 |
| Feb | -12 | -12 | -23 | -16 |
| Mar | -12 | -12 | -23 | -16 |
| Apr | -9 | -9 | -18 | -13 |
| May | -3 | -3 | -9 | -5 |
| Jun | 2 | 2 | -2 | 1 |
| Jul | 7 | 7 | 1 | 4 |
| Aug | 5 | 5 | 0 | 3 |
| Sep | 1 | 1 | -5 | -1 |
| Oct | -4 | -4 | -13 | -8 |
| Nov | -7 | -7 | -18 | -12 |
| Dec | -10 | -10 | -21 | -14 |
Average hourly temperature in Longyearbyen
A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 7°C, and coldest before dawn in March, near -17°C.
Longyearbyen weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | -11° / -16° | 43 | 8.9 | 10.9 | 0 | 0.0 |
| Feb | -12° / -16° | 31 | 7.1 | 9 | 1 | 0.0 |
| Mar | -12° / -17° | 35 | 8.4 | 10.2 | 10 | 0.0 |
| Apr | -9° / -13° | 23 | 6.8 | 8.7 | 19.3 | 0.0 |
| May | -3° / -5° | 21 | 6 | 7.7 | 24 | 0.0 |
| Jun | 2° / 1° | 18 | 5 | 3.7 | 24 | 0.0 |
| Jul | 7° / 4° | 32 | 8.2 | 1.1 | 24 | 0.7 |
| Aug | 5° / 3° | 40 | 9 | 2.2 | 22.8 | 0.3 |
| Sep | 1° / -1° | 45 | 9.8 | 5.3 | 13.7 | 0.0 |
| Oct | -4° / -8° | 41 | 9.1 | 9 | 4.4 | 0.0 |
| Nov | -7° / -12° | 47 | 10.3 | 12.2 | 0 | 0.0 |
| Dec | -10° / -14° | 45 | 9.7 | 11.9 | 0 | 0.0 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Longyearbyen gets about 418 mm of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.
The wetter season lasts 5.4 months, from around Aug 12 to Jan 22, peaking in September at about 35% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jun 9.
November is the wettest month by volume, with 47 mm over about 10 wet days; June is the driest, with 18 mm. Some of the cold-season precipitation falls as snow.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 29 | 26 | 26 | 23 | 19 | 17 | 26 | 29 | 33 | 30 | 33 | 32 |
| Rain days | 9 | 7 | 8 | 7 | 6 | 5 | 8 | 9 | 10 | 9 | 10 | 10 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 29 | 9 |
| Feb | 26 | 7 |
| Mar | 26 | 8 |
| Apr | 23 | 7 |
| May | 19 | 6 |
| Jun | 17 | 5 |
| Jul | 26 | 8 |
| Aug | 29 | 9 |
| Sep | 33 | 10 |
| Oct | 30 | 9 |
| Nov | 33 | 10 |
| Dec | 32 | 10 |
Monthly rainfall
Over a full year, Longyearbyen collects about 418 mm of rain across 98 wet days — roughly 35 mm in an average month.
It doesn’t fall evenly. November is the wettest month with 47 mm, while June is the driest at just 18 mm. The three wettest months alone bring about 33% of the year’s total, and some of the cold-season precipitation falls as snow.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 43 | 31 | 35 | 23 | 21 | 18 | 32 | 40 | 45 | 41 | 47 | 45 |
| Rain days | 9 | 7 | 8 | 7 | 6 | 5 | 8 | 9 | 10 | 9 | 10 | 10 |
| Snow days | 11 | 9 | 10 | 9 | 8 | 4 | 1 | 2 | 5 | 9 | 12 | 12 |
| Rainfall (mm) | Rain days | Snow days | |
|---|---|---|---|
| Jan | 43 | 9 | 11 |
| Feb | 31 | 7 | 9 |
| Mar | 35 | 8 | 10 |
| Apr | 23 | 7 | 9 |
| May | 21 | 6 | 8 |
| Jun | 18 | 5 | 4 |
| Jul | 32 | 8 | 1 |
| Aug | 40 | 9 | 2 |
| Sep | 45 | 10 | 5 |
| Oct | 41 | 9 | 9 |
| Nov | 47 | 10 | 12 |
| Dec | 45 | 10 | 12 |
Snow in Longyearbyen
Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.
Longyearbyen averages about 92 snowy days a year. Snow falls only in scattered spells rather than a settled season.
November is snowiest, with roughly 12 days of snow and an estimated 46 cm of snowfall. Over the year that adds up to an estimated 369 cm of snow.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Snow days | 11 | 9 | 10 | 9 | 8 | 4 | 1 | 2 | 5 | 9 | 12 | 12 |
| Snowfall (cm) | 50 | 42 | 43 | 31 | 25 | 14 | 3 | 8 | 16 | 39 | 46 | 52 |
| Snow days | Snowfall (cm) | |
|---|---|---|
| Jan | 11 | 50 |
| Feb | 9 | 42 |
| Mar | 10 | 43 |
| Apr | 9 | 31 |
| May | 8 | 25 |
| Jun | 4 | 14 |
| Jul | 1 | 3 |
| Aug | 2 | 8 |
| Sep | 5 | 16 |
| Oct | 9 | 39 |
| Nov | 12 | 46 |
| Dec | 12 | 52 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Longyearbyen, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.
The clearer part of the year begins around February 23 and lasts for 4.9 months, ending around July 20. The clearest month is April, when the sky is clear, mostly clear, or partly cloudy 24% of the time on average.
The cloudier part of the year begins around August 29 and lasts for 3.8 months, ending around December 22. The cloudiest month is October, when it is overcast or mostly cloudy 92% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 15 | 14 | 18 | 24 | 18 | 18 | 14 | 13 | 9 | 8 | 9 | 12 |
| Cloudier (%) | 85 | 86 | 82 | 76 | 82 | 82 | 86 | 87 | 91 | 92 | 91 | 88 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 15 | 85 |
| Feb | 14 | 86 |
| Mar | 18 | 82 |
| Apr | 24 | 76 |
| May | 18 | 82 |
| Jun | 18 | 82 |
| Jul | 14 | 86 |
| Aug | 13 | 87 |
| Sep | 9 | 91 |
| Oct | 8 | 92 |
| Nov | 9 | 91 |
| Dec | 12 | 88 |
Daylight, sunrise and sunset
Hours of daylight through the year, with sunrise and sunset times.
The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around April 23, brings about 24 hours of light; the shortest, around January 1, only 0 hours — a swing of roughly 24 hours.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 0.0 | 1.0 | 10.0 | 19.3 | 24.0 | 24.0 | 24.0 | 22.8 | 13.7 | 4.4 | 0.0 | 0.0 |
| Sunrise (AM) | — | — | 7:04 | 2:30 | — | — | — | — | 5:07 | 9:16 | — | — |
| Sunset (PM) | — | — | 5:10 | 9:25 | — | — | — | — | 6:36 | 2:09 | — | — |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 0.0 | — | — |
| Feb | 1.0 | — | — |
| Mar | 10.0 | 7:04 | 5:10 |
| Apr | 19.3 | 2:30 | 9:25 |
| May | 24.0 | — | — |
| Jun | 24.0 | — | — |
| Jul | 24.0 | — | — |
| Aug | 22.8 | — | — |
| Sep | 13.7 | 5:07 | 6:36 |
| Oct | 4.4 | 9:16 | 2:09 |
| Nov | 0.0 | — | — |
| Dec | 0.0 | — | — |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Longyearbyen averages about 2 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 4 days.
The sunnier stretch runs 4.7 months, from around Mar 16 to Aug 5. The sunniest month is April, with roughly 3 sunny days (gloomy).
The greyest month is November, down near 1 sunny days — about 80% fewer than the April peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 1 | 1 | 2 | 3 | 3 | 2 | 3 | 2 | 1 | 1 | 1 | 1 |
| Sky | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy |
| Sunny days | Sky | |
|---|---|---|
| Jan | 1 | Gloomy |
| Feb | 1 | Gloomy |
| Mar | 2 | Gloomy |
| Apr | 3 | Gloomy |
| May | 3 | Gloomy |
| Jun | 2 | Gloomy |
| Jul | 3 | Gloomy |
| Aug | 2 | Gloomy |
| Sep | 1 | Gloomy |
| Oct | 1 | Gloomy |
| Nov | 1 | Gloomy |
| Dec | 1 | Gloomy |
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.
In Longyearbyen, the air stays dry or comfortable essentially all year. Even in January, the muggiest month, it feels humid or worse only about 0% of the time — humidity is not something you need to plan around here.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Dry (%) | |
|---|---|
| Jan | 100 |
| Feb | 100 |
| Mar | 100 |
| Apr | 100 |
| May | 100 |
| Jun | 100 |
| Jul | 100 |
| Aug | 100 |
| Sep | 100 |
| Oct | 100 |
| Nov | 100 |
| Dec | 100 |
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Across the year, average wind speed in Longyearbyen is typically calm, near 10 km/h, and varies little with the seasons.
The windier part of the year lasts 5.7 months, from around Oct 15 to Apr 5. The windiest month is January, averaging about 12 km/h (calm).
The calmer part of the year runs from around Apr 6 to Oct 14, with June the calmest month at about 8 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 12 | 11 | 11 | 10 | 9 | 8 | 9 | 9 | 9 | 10 | 11 | 12 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 12 | calm |
| Feb | 11 | calm |
| Mar | 11 | calm |
| Apr | 10 | calm |
| May | 9 | calm |
| Jun | 8 | calm |
| Jul | 9 | calm |
| Aug | 9 | calm |
| Sep | 9 | calm |
| Oct | 10 | calm |
| Nov | 11 | calm |
| Dec | 12 | calm |
Best time to visit Longyearbyen
To characterize how pleasant the weather is in Longyearbyen throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Longyearbyen rarely gets warm enough to lift this score — no time of year really suits general outdoor tourist activities here.
The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.7 | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 |
| Rating | poor | poor | poor | poor | poor | poor | poor | poor | poor | poor | poor | poor |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 0.0 | poor |
| Feb | 0.0 | poor |
| Mar | 0.0 | poor |
| Apr | 0.0 | poor |
| May | 0.0 | poor |
| Jun | 0.0 | poor |
| Jul | 0.7 | poor |
| Aug | 0.3 | poor |
| Sep | 0.0 | poor |
| Oct | 0.0 | poor |
| Nov | 0.0 | poor |
| Dec | 0.0 | poor |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Longyearbyen rarely gets warm enough to lift this score — no time of year really suits hot-weather activities here.
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
What to pack for Longyearbyen, by month
Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.
For a warm-season trip around July (highs near 7°C), the essentials are a warm layer, a heavy coat and rain gear. In the cold season around March (highs near -12°C), pack a warm layer, a heavy coat and rain gear.
In July, Longyearbyen sees daytime highs around 7°C and nights near 4°C. Pack a warm layer. Worth having: a heavy coat and rain gear. About 8 days see rain.
UV index (midday) in Longyearbyen by month
Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.
Under clear skies, the midday UV index in Longyearbyen peaks around June 18 at about 2 (moderate) — sun protection is rarely needed. It bottoms out near January 1 at about 0 (low).
The midday index never reaches 3, the level where the WHO starts recommending sun protection.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 0 | 0 | 0 | 1 | 2 | 2 | 2 | 2 | 0 | 0 | 0 | 0 |
| Level | Low | Low | Low | Low | Low | Moderate | Low | Low | Low | Low | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 0 | Low |
| Feb | 0 | Low |
| Mar | 0 | Low |
| Apr | 1 | Low |
| May | 2 | Low |
| Jun | 2 | Moderate |
| Jul | 2 | Low |
| Aug | 2 | Low |
| Sep | 0 | Low |
| Oct | 0 | Low |
| Nov | 0 | Low |
| Dec | 0 | Low |
Average hourly UV index in Longyearbyen
Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.
The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
UV falls off far faster than brightness as the sun drops, so the low midday peaks here mean the modeled index stays below 3 at every hour — sun protection is rarely a concern.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| UV ≥ 6 (h/day) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 0 | 0 |
| Feb | 0 | 0 |
| Mar | 0 | 0 |
| Apr | 0 | 0 |
| May | 0 | 0 |
| Jun | 0 | 0 |
| Jul | 0 | 0 |
| Aug | 0 | 0 |
| Sep | 0 | 0 |
| Oct | 0 | 0 |
| Nov | 0 | 0 |
| Dec | 0 | 0 |
Growing season
The growing season in Longyearbyen typically lasts about 89 days, from around June 12 to September 8 — the span where a frost-free day is more likely than not. It is reliably frost-free from June 24 to August 20.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 3 | 2 | 1 | 2 | 7 | 62 | 99 | 91 | 38 | 8 | 4 | 2 |
| Frost nights | 31 | 28 | 31 | 30 | 31 | 23 | 0 | 10 | 30 | 31 | 30 | 31 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 3 | 31 |
| Feb | 2 | 28 |
| Mar | 1 | 31 |
| Apr | 2 | 30 |
| May | 7 | 31 |
| Jun | 62 | 23 |
| Jul | 99 | 0 |
| Aug | 91 | 10 |
| Sep | 38 | 30 |
| Oct | 8 | 31 |
| Nov | 4 | 30 |
| Dec | 2 | 31 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Longyearbyen banks about 0 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around January.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 0 |
| Feb | 0 |
| Mar | 0 |
| Apr | 0 |
| May | 0 |
| Jun | 0 |
| Jul | 0 |
| Aug | 0 |
| Sep | 0 |
| Oct | 0 |
| Nov | 0 |
| Dec | 0 |
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
Longyearbyen receives about 1.9 kWh/m² a day of solar energy on average — dim — with a clear seasonal swing between 0.0 and 6.2 kWh/m².
The brighter stretch of the year lasts 4.8 months, from around Apr 3 to Aug 26. The brightest month is June, averaging about 5.9 kWh/m² (bright).
The dimmest month is January, down near 0.0 kWh/m² — roughly 100% less than the June peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 0.0 | 0.0 | 0.8 | 3.1 | 5.5 | 6.0 | 4.1 | 2.5 | 0.9 | 0.1 | 0.0 | 0.0 |
| Level | Dim | Dim | Dim | Moderate | Bright | Bright | Bright | Moderate | Dim | Dim | Dim | Dim |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 0.0 | Dim |
| Feb | 0.0 | Dim |
| Mar | 0.8 | Dim |
| Apr | 3.1 | Moderate |
| May | 5.5 | Bright |
| Jun | 6.0 | Bright |
| Jul | 4.1 | Bright |
| Aug | 2.5 | Moderate |
| Sep | 0.9 | Dim |
| Oct | 0.1 | Dim |
| Nov | 0.0 | Dim |
| Dec | 0.0 | Dim |
Where is Longyearbyen?
Longyearbyen sits at 78.2°N, 15.6°E, 1 m above sea level, in Svalbard and Jan Mayen. The nearest listed city is Alta, 945 km away.
What Longyearbyen looks like
Topography around Longyearbyen
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Longyearbyen.
Within 3 km, the terrain around Longyearbyen has significant variations in elevation — a maximum elevation change of 485 m around an average of 113 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,061 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,255 m.
The land around Longyearbyen is covered by water (35%), bare terrain (30%) and moss and lichen (27%) within 3 km, bare terrain (31%), water (29%) and moss and lichen (22%) within 16 km, and snow and ice (30%), water (29%) and bare terrain (26%) within 80 km.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Longyearbyen (78.2233°, 15.6469°, elevation 1 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).