The climate
of Western Europe is milder in comparison to other areas of the same latitude
around the globe due to the influence of the Gulf Stream. The Mediterranean’s
waters are not as deep as the large oceans, allowing it to become a heat store
tempering winters along its coastlines. The Gulf Stream is nicknamed
"Europe's central heating", because it makes Europe's climate warmer
and wetter than it would otherwise be. The North Atlantic Oscillation and
Arctic Oscillation also play large roles in determining the amount of Arctic
air that penetrates southward diminishing the Gulf Stream’s warming effects
during winter.
Comparing to
other parts of the globe, the average temperature throughout the year in Naples
is 16 °C (60.8 °F), while it is 13 °C (55.8 °F) in New York City, virtually the
same latitude. Berlin, Germany; Calgary, Canada; and Irkutsk, in the Asian part
of Russia, lie on around the same latitude; January temperatures in Berlin
average around 8 °C (15 °F) higher than those in Calgary (although Calgary sits
1200m higher in altitude), and they are almost 22 °C (40 °F) higher than average
temperatures in Irkutsk. This difference is even larger on the northern part of
the continent; the January average Norway is almost 15 °C warmer than the January
average in Nome, Alaska, both towns are situated upwind on the west coast of
the continents at 65°N, and as much as 42 °C warmer than January average in
Yakutsk which is actually slightly further south. Further south the oceanic
climate of Europe compares thermally to North America, at around 48°N Rennes,
France has about an equal average temperature throughout the year to Seattle,
Washington, although the latter has drier summers with much wetter winters