The Climate of Shetland
Shetland lies in the track of the Atlantic depressions and is bathed by the relatively warm waters of the Slope Current, flowing north along the edge of the Continental Shelf, so the climate is classed as temperate maritime.
Summers in Shetland are usually showery, bright and cool, winters dark and wild, but also mild. The climate's slightly warmer than the Gulf of Alaska, which lies on the same 60th parallel of latitude.
On the fine days, which can occur at any time of year, the islands appear idyllic; in winter hurricanes they're awe-inspiring. But, having said that, when the weather's good you can have a beach all to yourself.
Settled spells of weather are unusual at any season, but the sunniest months are April to August.
Because we're so far north, from mid-May to mid-July Shetland enjoys the 'simmer dim' (summer twilight) when the sun only dips below the northern horizon for a few hours. In fine weather this can bring the islands almost 19 hours of sunshine a day (we pay for these Scandinavian 'white nights' in midwinter when, by contrast, there are fewer than six hours of daylight).
Rainfall averages 1,220mm a year, lower than in many other north-western parts of Britain and less than half the total for Fort William. Fortunately for our visitors, almost three quarters of the rain falls in winter, with the driest weather usually between April and August.
Shetland can be a very windy place. The average wind speed over the year is around Force 4 (15mph, or 24kph) and, in winter, speeds of hurricane force 12 are not unknown. Gales are much less common between April and September, though, and there can be flat calm days at any time of year. The islands are quite hilly, with many sheltered coastal coves (called geos in Shetland dialect), so it’s usually quite easy to find a sheltered spot for a picnic.
Fog occurs mainly in summer but is usually confined to the east coast of the islands while the west side bathes in sunshine.
Although Shetland's as far north as Greenland's Cape Farewell, snow rarely lies long. Gales of rain, squalls of sleet and occasional 'days between weathers' characterise the long winter, but frosts are rarely severe or prolonged.
One of the great experiences during the Shetland winter is the ‘Northern Lights’, or aurora borealis. Aurorae occur in the sky above the earth’s polar regions. The northern sky takes on a greenish glow, with other colours such as pink, blue, orange or purple also present at times. Often, there are well-defined rays or ‘curtains’ of light. Displays vary greatly in intensity – and may do so over an hour or so - but an outstanding display can occupy the whole of the northern half of the sky and shed a noticeable light over the landscape. Less powerful aurorae will produce a uniform glow towards the north-west.
Because Shetland lies closer to the north pole than any other part of the British Isles, it’s the best place to see the ‘Northern Lights’. Over a typical winter, a keen observer checking the skies on every clear night could certainly expect to see the aurora several times, with quite a number of low-level displays and possibly one or two more spectacular ones. However, the important thing to bear in mind is that aurorae are hard to predict and, even if the aurora is present, thick cloud may stop you seeing it.
Read more about seeing the Northern Lights in Shetland here.
Thanks to the influence of the sea, Shetland doesn’t experience great extremes of temperature. On average, August is the warmest month, with a daily average maximum of 15°C. The highest temperatures officially recorded at Lerwick’s observatory – which is about 80m above sea level – are just over 23°C. However, in sheltered spots at lower levels, the mercury may well rise into the high 20s on particularly sunny, calm days.
February is the coldest month, with an average maximum of 5.4°C. Air frost occurs, on average, on 15 days each year. That’s a very low figure by British standards and is similar to coastal areas of Cornwall or Devon. The average for Manchester is 40 and some upland areas of Britain experience more than 80.
Sea temperature ranges from around 6°C (42.8°F) in January to 13°C (55.4°F) in August.
On This Site
- Read about the unique geography of Shetland
- Enjoy some of the many outdoor activities on offer in Shetland