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The history of Columbia County, Wisconsin, containing an account of its settlement, growth, development and resources; an extensive and minute sketch of its cities, towns and villages--their improvements, industries, manufactories, churches, schools and societies; its war record, biographical sketches, portraits of prominent men and early settlers; the whole preceded by a history of Wisconsin, statistics of the state, and an abstract of its laws and constitution and of the constitution of the United States
(1880)

Oldenhage, H. H.
Climatology of Wisconsin,   pp. [121]-128 PDF (3.9 MB)


Page 123


CLIMATOLOGY OF WISCONSIN.
     The extreme summer climate of the eastern United States is owing to
the southerly and
southwesterly winds, which blow with great regularity during this season,
and, after traversing
great areas of tropical seas, bear the warmth and moisture of these seas
far inland, and give this
region the peculiar semi-tropical character of its summers. The average temperature
of summer
varies between 8o0 for the Gulf states, and 6o' for the extreme north. While
in the Gulf states
the thermometer often rises to ioo°', in the latitude of Wisconsin this
occurs-very seldom. During
winter the prevailing winds are from the northwest.  These cold blasts from
the Arctic sea are
deflected by the Rocky mountains, sweep down unopposed into lower latitudes,
and produce all
the rigors of an arctic winter. The mean temperature for this season varies
between 6o' for the
Gulf coast and 15. for the extreme northern part of Wisconsin.  In the northern
part of the
valley the cold is sometimes so intense that the thermometer sinks to the
freezing point of
mercury.
     The extreme of heat and cold would give a continental climate if this
extreme were not accom-
panied by a profusion of rain. The southerly winds, laden with m'oisture,ý
distribute this moist.
ure with great regularity over the valley.   The amount of rainfall, greater
in summer than in
winter, varies, from the Gulf of Mexico to Wisconsin, from 63 inches to 30
inches. On the At.
lantic coast, where the distribution is more equal throughout the year on
account of its proximity
to the ocean, the amount varies, from Florida to Maine, from 63 to 40 inches.
The atmospheric
movements on which, to a great extent, the climatic conditions of the eastern
United States
depend, may be summed up as follows:
      i. That the northeast trades, deflected in their course to south and
southeast winds in
their passage through the Carribean Sea and the Gulf of Mexico, are the warm
and moist winds
which communicate to the Mississippi valley and the Atlantic slope their
fertility.
     "2. That the prevalence of these winds from May to October communicates
to this region
a sub-tropical climate.
     "3. That in the region bordering on the Gulf of Mexico, the atmospheric
disturbances are
propagated from south to north; but in the northern and middle states, owing
to a prevailing
upper current, from west to east.
     "t4. That while this upper current is cool and dry, and we have
the apparent anomaly of
rain storms traveling from west to east, at the same time the moisture supplying
them comes from
the south.
     "5. That, in the winter, the south and southeast winds rise into
the upper current, while
the west and northwest winds descend and blow as surface winds, accompanied
by an extraor.
dinary depression of temperature, creating, as it were, an almost arctic
climate.
     "6. That the propagation of the cold winds from west to east is
due to the existence of a
warmer and lighter air to the eastward.
     "7. That in summer the westerly currents seldom blow with violence,
because, in passing
over the heated plains, they acquire nearly the same temperature as the southerly
currents, but in
winter the conditions are reversed.")
     The line of conflict of these aerial currents, produced by unequal atmospheric
pressure,
shift so rapidly that the greatest changes of temperature, moisture, and-wind,
are experienced
within a few hours, these changes usually affecting areas of great extent.
In the old world, on
the other hand, the momntain systems, generally running from east to west,
offer an impediment,
especially to the polar currents, and the weather is therefore not so changeable.
     Wisconsin, situated in the upper and central part of the Mississippi
valley, is subject to the
same general climatic conditions which give this whole area its peculiar
climate.
     The highest mean summer temperature is 72° Fahrenheit in the southwestern
part of the
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