The Botany of Iceland - 01.12.1914, Síða 98

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THORODDSEN
Table IV shows that the climate oí' the interior districts is more
continental than that at the coast, the summers being warmer and
the winters colder. The differences in tlie temperature of the stations
at the head of a tjord is greater than of those situated outside;
Berufjord, for instance, is warmer than Papey. There are, however,
exceptions to this in places where cold currents and drift-ice exert
an influence; thus Bordeyri at the head of Húnaflói has the same
annual temperature as Grímsey, — Baufarhöfn and Skeggjastaðir are
even colder, being much influenced by the Polar currents.
During a period of 38 years (1873—1906) there have been on
an average 166 frosty days annually at Stykkisholm, 109 in the
Vestmannaeyjar, 158 at Berufjord and 192 on Grímsey. At Stóri-
nupur near the southern lowlands, at a height of 135 metres above
sea-level, during a period of 20 years, there have been on an average
200 frosty days. The frost appears early and disappears late. Frosty
days are frequent till far into early summer, but in South and West
Iceland midsummer is usually free from frost. On Grímsey it freezes
in all the months of the year, but in July and August there are on
an average only two frosty days monthly; at Berufjord, in the Vest-
mannaeyjar and at Stykkisholm, July has been free from frost during
a period of 33 years. On the northernmost peninsulas and in
districts situated at the highest levels there is no doubt that none
of the months is entirely free from frost. When drift-ice lies along
the coast in North Iceland the ground is usually frost-bound
throughout summer, and in the vast extents of bog-land on the
piateau, at a height of 400—500 metres the sub-surface ice never
thaws entirely.
Table V shows the temperature at all the meteorological sta-
tions in Iceland during the years 1874—1901. The observations
from the chief stations extend over a period of more than 25 —
28 years; at other stations 15—22 years and in some 5—12 years.
For the sake of completeness some observations from three sta-
tions have been included, although they cover a period of 2—3
years only. Table VI gives many more and fuller information re-
garding temperature-conditions at the main stations during a period
of 33 years (1872—1906).
The climate of Iceland is very damp although the precipitation
is not considerable; it is, however, much greater than in Denmark.
Sleet and drizzling rain are of constant occurrence, but the amount
of precipitation on a single day is rarely sufficient to be of any con-