Climate 

Summer snowfalls are only occasional and mostly short-lived, and though dull, wet weather tends to be cold, frost is rather infrequent. Continuous daylight prevents excessive drops in nighttime temperature, but there can be a noteworthy chill from midnight into the small hours. Cold, backward springs do at least have the advantage of postponing the biting insect curse a little longer, but warm, early conditions bring it forward. This scourge of the north begins on average around 15-16 June, but can vary up to a week or more either side of this, according to the prevailing conditions. The mosquitoes are everywhere, but worst of all in the bogs and marshes. And in some years the black flies, midges and various gad flies add to the problem. Frequent anointing with insect repellent makes life bearable, but its effect never lasts nearly as long as the makers claim.

There is some geographical variation in climate also, with a quite marked gradient in oceanicity between the coast and the interior. The northwest coast of Norway is the most oceanic district. Precipitation here is fairly even through the year or becomes higher in winter, and rises to 1,500 mm on the high maritime mountains of the Arctic Circle. Although precipitation over much of interior Sápmi is mostly quite low, at around 300-500 mm (and just 250 mm in places) , it tends to fall in the summer months but as snow from September and through the winter. In most inland areas, the ground is snow-covered from October to April (200-250 days). Winter temperatures follow the same patters, with a February mean of -2.5° at Sørøy on the coast west of Hammerfest, compared with -14°C far inland at Kautokeino. An extreme low of -51.4°C has been recorded at Karasjok, which may be in a frost hollow, but a summer maximum of 30°C is also known there. Karesuando in northern Sweden reported -48.7°C and Kittilä in Finnish Sápmi -51.5°C in January 1999.

The temperature pattern is reversed in summer and an area extending 250 km north of Luleå in Sweden and Tornio in Finland has a summer maximum of 28-30°C. The more continental conditions of the interior give cheerful, sunny summers on the whole, and the bleak, cold and cloudy climate of the outer Varanger Fjord can make a miserable contrast at times. Although on the coast, Vardø has the unenviable reputation of being the coldest town in Europe, on the basis of its mean monthly temperatures. On average there are only 30 days in the year when the temperatures exceeds 10°C, and the mean temperature of the warmest month (July) is 8.9°C. Icy winds often blow relentlessly, and can spoil bright, sunny days. Yet it can be freezing cold by the shore, but still and almost warm on fell plateau some 400 m higher up, as a result of off-the-mountain winds that roll down from high ground. At other times, winds on the high ground can produce a deathly coldness.

Spring is slow to arrive in these northern regions, and during the long road journey to the Arctic from southern Sweden or Norway, visitors in late May or early June usually have the sense of heading backwards into winter. By late May in the south, the broadleaved trees have been in full leaf for some time and many birds already have young. In an average year, the birches of  are then still in bud, and they may stay thus for another two or three weeks in a backward spring, especially on the higher ground. In mid May there may still be extensive snow-cover, with the lakes iced over, even on the low ground, and by the end of the month large drifts often linger in sheltered places within the forests. The bogs are still sufficiently frozen below the surface to allow safe walking over even their more treacherous parts, and the taller Sphagnum hummocks hold tiny ice cores. At first hardly anything is in flower, and herbaceous growth struggles to appear. In 1993, even by 24 June, the birches on some parts of Sápmi were still only in bud and vast snowfields covered the upland area of Ifjordfjell farther north, at only 350-450 m. By contrast, the spring of 2002 was exceptionally early throughout Scandinavia, and the Sápmi trees were all in full leaf by the beginning of June, while little snow remained on the higher fells. On average the growing season is short, and much of Sápmi has only 100-150 days annually with mean daily temperatures above 5°C, the number of days decreasing with latitude.

This is the land of the midnight sun, and the 24 hours of continuing daylight prevailing during the summer months can change the scene quite rapidly in a forward year, and give a special physiological regime for plants, and probably animals too. Photosynthesis is continuous and plant growth rapid, once the cold of winter has retreated. Temperature is also affected favorably, because the cooling effect of nighttime darkness is so much reduced.  A few days of warm sunny weather can transform the birch wood scene from a drab brown landscape to one of verdant contrast. In a warm spring some plants advance rapidly through their flowering period. The Cloudberry blossoms appear in a profusion that carpets many of the bogs in white, with the appearance of a sprinkling of new-fallen snow, but the petals soon drop, and by the end of June –or even earlier- the berries are often well formed and red (they turn golden-yellow when fully ripe). Warm conditions may also mean rapid snowmelt and local flooding, as the rivers quickly rise to peak levels. The mighty Pite _-2DOTS-lv, north of Arvidsjaur, runs over rapids at the main road bridge on route 45, and after a sudden thaw looks to be boiling, with a cloud of spray hanging over its awesome torrent.

On the Arctic Circle the sun does not dip below the horizon between mid-May an the end of July, and with further distance north the duration of continuous daylight increases. The light becomes mellow and the shadows extremely long when the sun reaches its lowest point, but after midnight, it is already becoming brighter as the sun rises again. Only on heavily overcast evenings is there any sense of impending darkness. The continuous daylight enlarges the scope for fieldwork, at least amongst those who do not feel the dictates of the internal clock. Walking against the sun on bright evenings after about 2100 hrs can be very trying, however, especially in long vegetation on the bogs, with perplexing contrasts between brightness above and shadow below. Many birds also have a quiet period for two or three hours either side of midnight, so that this is not a particularly useful time to seek them. Finland is one time zone (one hour) ahead of Sweden and Norway, which are one hour in advance of Britain.

Except during wet or misty weather, visibility is usually very good, with a clear, smog-free atmosphere. During unsettles weather, with well-developed cumulo-numbus cloud formations, there are often dramatic and characteristic skies, which probably owe their layered effect to the low trajectory of the sun. Thunderstorms develop frequently and brilliant rainbows appear s localized deluges give way to sunshine again, with spectacular masses of piled-up clouds. Fog at low levels is unusual in summer, but on still, cool evenings thin and patchy mist sometimes condenses over the bogs, adding to the sense of the mysterious.

Source courtesy of: Lapland A Natural History. Derek Ratcliffe 2005