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Central
Switzerland
is
not
only
the
cradle
of
the
Swiss
Confederation.
It
is
not
only
the
heart
of
extensive
drainage
system
whose
ramifications
spread
over
large
parts
of
Europe.
It
is
an
area
where
very
diverse
climates
meet
and
overlap.
Relatively
mild
and
moist
maritime
air
masses
flow
across
form
the
west.
But,
under
the
influence
of
the
continental
climate
of
the
Hinterland,
a
drier,
colder
wind
blows
from
the
east,
warming
up
noticeably
in
the
course
of
the
summer.
A
cold
polar
wind,
the
notorious
“Black
Breeze”,
comes
from
the
north,
a
moist
wind,
the
“Föhn”,
from
the
south.
Thus
Switzerland
enjoys
a transitions in the mountains. The annual rainfall on the
Jungfrau
is
4,000
mm,
and
yet
a
few
kilometres
away,
in
Valais,
it
is
only
500
mm
Considering
the
latitude,
the
climate
is
rough.
Three
quarters
of
Switzerland
has
an
annual
rainfall
of
more
than
a
metre.
the
very
rainy
area
round
St.
Gothard
is
popularly
known
as
“Switzerland’s
chamber
pot”
–
not
very
flattering
for
a
region
of
such
strategic
and
historical
importance.
The
higher
you
go,
the
it
rains
or
snows.
On
the
Säntis
it
snows
on
about
150
days
a
year.
The
climate
is
varied.
Near
La
Brévine,
in
the
Neuchâtel
Jura
,
a
veritable
Swiss
Siberia,
temperatures
can
sink
to
minus
30
degrees
C
in
winter.
At
the
same
time,
palms
grow
in
Montreux
and
numerous
tropical
plants
flourish
on
the
islands
of
Lake
Maggiore.
And
yet
the
mountains
are
not
always
damp
misty;
above
the
clouds
the
air
is
generally
quite
dry.
While
the
lowlands
and
valleys
are
wrapped
in
a
thick,
gloomy
mantle
Of
mist
in
the
winter,
which
can
drive
even
the
greatest
optimist
to
despair,
high
in
the
mountains
it
is
often
fine,
and
even
hot,
and
tourists
can
sunbathe
as
if
they
were
on
a
Mediterranean
or
Caribbean
beach.
Nevertheless,
with
their
large
number
of
rainy
days
and
rather
frequent
cloud,
the
mountains
are
basically
under
the
influence
of
a
maritime
climate. The
Atlantic
is
a
source
of
moist
winds
which
cross
the
Continent
from
west
to
east.
When
they
encounter
the
Jura
or
the
Alps,
the
tamp
air
masses
ascend,
cool
down,
and
lose
most
of
their
moisture
in
the
from
of
more
or
less
heavy
rain.
The
south
side
of
the
range
escapes
the
rain;
it
is
a
favoured,
relative
dry
area.
The
south
wind
has
a
similar
effect.
In
this
case,
the
rain
falls
mainly
on
the
southern
slopes
of
the
Alps
on
each
side
of
the
Rhine
–
Rhôhne
trench
The
central
valley
of
Valais
thus
remains
rather
dry,
with
only
500
to
800
mm
of
rain
per
year.
The
winds
play
an
essential
part
even
in
the
regional
climate.
The
eastern
slopes
of
the
mountains
are
warmed
by
the
sun
in
the
early
morning.
The
air
rises,
passes
the
high
peaks,
and
cumulus
from.
This
upward
movement
of
air
in
the
mountains
draws
a
current
of
air
down
into
the
valleys
powerful
enough
to
bend
and
distort
the
tall
poplars.
During
the
night
the
process
is
reversed.
The
colder,
heavier
air
of
the
heights
sinks
into
the
valleys.
In
reaction
to
this,
the
mountain
breeze
now
up
the
valley
–
in
the
opposite
direction
to
the
morning
breeze.
The
föhn
wind
is
still
a
bit
of
a
mystery
to
the
meteorologists.
At
one
time
it
was
believed
that
it
came
from
the
Sahara.
But
now
we
know
that
this
warm,
moist
wind
comes
from
the
Mediterranean
area,
although
it
is
sometimes
accompanied
by
Sahara
currents;
these
may
carry
reddish
–
coloured
sand
with
them,
traces
of
which
can
then
be
seen
on
the
Alpine
snowfields.
The
föhn
wind
passes
through
several
phases
on
its
way
northwards.
In
the
southern
Alps
it
releases
its
moisture
in
heavy
falls
of
rain
which
transform
the
streams
into
torrents.
Then
it
crosses
the
mountain
chain,
continues
northwards,
and
blows
across
the
plateau.
It
dries
out
the
air,
disperses
mist,
and
miraculously
clears
the
atmosphere.
If
a
few
clods
still
persist
around
the
northern
peaks
are
surrounded
by
a
“föhn
window”,
a
bright,
sunny
zone.
Föhn
is
both
beneficial
and
harmful.
It
favours
the
growth
of
plants
that
need
warmth,
like
vines,
maize,
and
chestnuts.
But
when
it
is
in
a
gusty
mood
it
destroy
woods
and
houses
and
even
cause
fires.
Föhn
precipitates
sudden
thaws
of
the
snow.
resulting
in
floods,
sometimes
of
catastrophic
proportions.
Finally
many
people
living
in
areas
affected
by
the
föhn
fear
the
wind
because
it
can
cause
sleeplessness,
migraines,
and
exhaustion. |
