Rain due to War – 1939 (2_31)
of this paper
World War II (WWII) drove Northern Europe into the hardest winter
for one hundred years is subject of a number of chapters. This
paper aims to show and discuss that not only Europe but the
whole northern hemispherefell prey to an arctic spell. United States and
China experienced severe cold inJanuary 1940, while Northern
Europe was back in ice age conditions for the duration of two months.
reasons for these occurrencesof ‘cold’ conditions in the winter of
1939/40 in Europe, it should not be ignored that military activities on
land may have disrupted the balance in the atmosphere by ‘squeezing’
humidity out of the air. Obviously, less water in the air, means colder
but dry air. A place where this could have happened was the Western
Front between France and Germany after the start of WWII, where more
than 2 million soldiers had been put in positions along this Front.
rained double or even triple the quantity as against recorded
long-term mean precipitation in areas which were within a fewhundred
kilometres range of this war front line. Some regional areas had
only days of rain during October. Just few weeks later the USA
experienced extremely dry air and alsorecorded low rain over the whole
country. (A) In the end of December, winter set in andtook the entire
Northern Hemisphere in its icy grip by early January 1940, and remained
frozen throughout the month.
details: (A) USA dried out, 2_32.
attempts to focus attentionon this ‘rain making’ phenomenon during
the initial war months in 1939. Only at this stage of WWII did the war
activities directly interfere with common ‘nature and climate’.
Thus this short period of time can be regarded as having gone through a
direct ‘clash’ between common nature – in a statistical sense -
and civilization. This can be compared with the sudden major eruption of
a volcano with global implications. The time it took for the spread of
volcanic ash and dust around the globe after the huge
eruption of the volcano Krakatoa in Indonesia on August 27, 1883 until
the end of the year may serve as an example.
In this case nature took charge and after a relativelyshort period of
time, the atmosphere returned to ‘equilibrium’, making it difficult
to prove the source and reasons for this specific meteorological event.
It would assist in researches on climate changes, if the impact
of WWII - during the first few months – was under consideration, or
when the war after having entered its 1st, 2nd or
3rd years has to be studied in detail. The German
meteorologist R. Scherhag,
observed a “great disruption incirculation” during thewinter of
1939/40 only, even though the winters that followed in 1940/41 and
1941/42 were also of similar nature. However, before the second
and third winters of the war, military activities took place
throughout theyear, giving nature time to move from ‘equilibrium to
equilibrium’ without a sudden disruption. Althoughthis aspect is
admittedly rather difficult to explain, one particularpractical example
is part of this study. This example demonstrates a link between
excessive rain in Central Europe (see this chapter), and the record
‘dry air’ in the United States from October to December 1939 (next
chapter). This is a substantial evidence of anthropogenic influence.
This proof, on a meteorologically sensitive issue, is presumably valid
only when WWII had just started. Why didthe USA, after a ‘normal’
year, suddenly receive only very dry air for three months, while the war
in Europe that ‘squeezed’ water out of the atmosphere only a few
continuing it should be stressed once again, that the making of the
arctic winter 1939/40 in Northern Europe is primarily a regional affair
due to war at sea in adjacent waters. Making the atmosphere rain and
pave way for arctic air should be regarded as a temporarily contributing
paper does not proposeto discuss physical/chemical processes in a
hydro-dynamic environment. Itaims onlyto show that with the start of
WWII certainevents occurred which cannot be relatedto conditions other
than war activities. However, war activities in this respect can mean
quite different thingsas mentioned below:
The war machinery and its activities penetratethe atmosphere
directly or indirectly with physical/chemical means, which subsequently
set processes in motion that eventually producerain; e.g. the raging of
war along the Western Front and many otherbattle fields and the burning
ofcities all over Poland during September 1939.
The war machinery and its activities also stirred
and mixed the seas and oceans, with the following results:
raised vapour and initiated flow of air, from Northern Scandinavia
or from Russia to the North and Baltic Sea;
Presumably cold air (colder than seasonal average) forced humid air into
increased precipitation, e.g. in Central Europe.
It started to ‘block’ the West Drift, commonly moving maritime air
from the Atlantic through Western Europe, via the North Sea. Instead,
continental air flew infrom the east.
The continental air, colder than maritime air, thathad been coming via
Scandinavia or the ‘corridor’ of the Southern Baltic Sea/Poland and
North Germany along until it reached the North Sea, could have been a
major contributor to the excessive rain along and behind the Western
The war in China was also a factor which should notbe ignored. However,
very little material from the Far East had been availablefor this study
which can at best help to attempt a basic assessment. Furthermore war in
China, wouldhave had hardly any impact on the autumn weather in Europe.
However, some relevance of this war on drought conditionsin the USA in
late 1939 cannot be ruled out.
The topics mentioned below will bediscussed in greater detail in
Sea cooling (2_16), concerning items 2a-d;
West Drift (2_12),concerning items 2c-d;
in China 1939 (2_33), concerning item 3;
dried out 1939 (2_32), concerning item 3.
lack of rain during the German invasion of Poland in September 1939 will
receive attention. This attack which wasan extremely destructive
military operation could possibly have derived Poland of ‘normal’
rain. If so, it could serve as a proof that military activities along
the Western Front kept Poland rainless. It would be a sadly ironic event,
if true (see below). The situation on Polish territory during
September 1939may have also contributed to the blocked ‘West Drift’
in a minor way.
final aspect, although speculative, should also be mentioned here. The
military onslaught on Poland during September 1939 was, until then, the
most massive military land war operation in such a short period of
time. It ended after four weeks, with Warsaw burning for many days. All
the material that had been thrown into the atmosphere, like that of the
burst of the Krakatoa 56 years earlier, could have served as
‘condensation nuclei’, if it had managed to travel a little
fartherto the west, contributing to heavy rain along the Western Front,
or influencing rain conditions further east, e.g. when Russian and
Japanese forces waged a week long battle on the boarder between Outer
Mongolia and Manchuku in August and September 1939. (A)
details: (A) War in China, 2_33.
processing: Water can condense in the air by the use of molecules as
condensation nucleus. Condensation occurs on a wide variety of
aerosol particlese.g. particles of dust, salt, desertsand or smoke.
These particles when condensed, usually lead to cloud
formation. Among the highly efficientcondensation nuclei are salt
particles produced by the evaporation of sea water. But it
now appears that particles produced by man-made fibresalso make a
biggest rain making experiment may have started in the autumn of 1939.
Since the 1st of September a lot of ‘seeds’ had been
pushed into the air. It was possible for themto ‘make’ rain and this
is precisely what happened. A several hundred kilometre long military
defence zone between France and Germany, the Maginot Line and the
Westwall, wereput into full operation immediately after the war had
started. It began to rain significantly onthe continent along the
Western Front. It rained more than the average in September, even more
heavily in October and November and still morein December before
Northern Europe was dragged into arctic weather conditions with frost,
ice and snow until March 1940. Only the firstfour war months, viz.
September to December 1939, are the subject for the following study
as, latest by December 1939, European weather had lost its
data indicate that excessive rain was fed by “seeding” due to war.
Rain fell within close distance of war activities in the West, while
further East the Poles waited in vain for rain.
neither big battles nor “shoot outs” occurred along the huge defence
system in the West, everything was done to improve defence capabilities
and to prepare two million soldiers for the worst. Therefore bothfronts
were busy day and night with transportation, construction, survey,
training and military encounters. The first substantial clash saw 700
French tanks and planes moving seven miles over the Saarland border,
while 300 air planes attacked German positions in the Aachen industrial
region and munitions area, some 125 miles further north, (NYT, 7
Sept.1939), encounters that occurred since then frequently. At the same
time British troops were landing on the continent rapidly, while German
planes targeted England for the first time, (NYT, ditto) the Royal
Air force bombed the isle of Sylt. (NYT 9 Sept 39). There were
several encounterswhich occurred in numerous placesalong the
Western Front and elsewhere every day.
without rain in September 1939
to anassessment by the German meteorological service, September 1939 was
considerably wet from the upper and middle of the Rhine region
(Duisburg/Cologne to Frankfurt/Darmstadt) eastward to Silesia. Large
parts of middle and southern Germany received double than average rain.
On 4th September, a wet warm high pressure front (1015 mb),
approached from the Atlantic, which brought to the whole of West Germany
mist and rain, but movedquickly eastwards. The warm front was
almost exactly in line with the French/German Westfront at 8:00 a.m. on
Sept4th, the with centre of a low pressure close
to Luxembourg and rain coming down in Germany, leaving nothing for
11th September,a low pressure(1,000mb) originatedwest of
Jutland, moved south to the Schelde area (12th), and to
Belgium (13th), bringing lots of rain to North Germany and
excess rain of 50mm to 100mm to Southern Germany. This low-pressure
cyclone moved through the North Sea, close to the sea mines that the
German Navy had started to lay quickly, across the middle of the North
Sea, at the outer edge of the German Bight. This could possibly be the
first example of acyclone being“attracted” by sea war activities
whichproduced “evaporation”. (A) At least the cyclone also gave
Poland some rain before the 13th of September but it was too
little, too late.
details: (A) Cyclones and shells, 2_21.
(NYT, 15 Sep. 1939) that Warsaw received heavy rain, was proved
wrong.It was only a drizzle in most areas (NYT, 17 Sept. 1939). By
then Warsaw was encircled. The Red Army marched into Poland from the
East. Days of the Polish Republic were numbered. The Nazis had
deployed5,000 planes in Poland (NYT, 25 Sept. 1939). On September 25,
1939, 240 German planes bombed Warsaw, dropping 560 tons ofbombs,
including the first 1,000 kg bomb. Meanwhile 1,000 batteries shelled the
city. 30 transport aircraft dropped 70 tons of fire-bombs. Warsaw was on
fire for many days. Poland surrendered. There was nothing butdust and
ashes from burning citieseastward around for a couple of days or weeks.
Did thisdust help topour horrendous rain on New York in early November
1939, recording 1.4 inches in one day? (NYT, 6 November 1939). But
some of the dust could also havebeen moved by easterly winds to the
Western Front contributing to excessive rain in Central Europe.
German Meteorological Service makesthe following assessment for
September 1939: Precipitation in North Germany is markedly below the
mean averages. The opposite occurred in all other parts of
Germany, with significantly higher quantity of rain than mean averages.
The September 1939precipitation in percentage termsof average figures
(1851-1930) for some places in Germany had been as follows:
(197 %); Frankfurt/Oder (197 %); Breslau (204 %); Ratibor (210 %);
Karlsruhe i.B. (208 %); Stuttgart (199 %); Ulm (226%); Wuerzburg
(215 %); Muenchen (212%).
1939– Raining ‘Cats and Dogs’
the West, Middle and South Germany volumes of rain recordedat most
observation stationswas more than double, in some cases even 3.5 times
more than usual, as follows: Augsburg 366%; Noerdlingen 362%,
Kaiserslautern 336 %, Wuerzburg 316 %.
to the war situation there is hardly any weather related
documentation available. With respect to Darmstadt it was reported
that it would be necessary to go back to the year 1882 to find a similar
volume of precipitation during a period ofthree months, i.e. Sept.-Nov.,
asthe autumn had never been so wet since more than 100 years.
The nearby city of Frankfurt a. M. recorded: 137%, 265%, 237% during the
time in question.
Black Forest and Freiburg i. Br. recorded 30 days of rain; a number of
other locations had up to 24 days of rain.
eye-witness report may serve to illustrate the special situation at the
Western Front. According to the New York Times, by mid October the West
Front saw a ‘Nazi Attack with 100,000 men’ and the following weather:
artillery whipped the German front line positions, roads and railroads
with shrapnel to hamper operations.
aidedflood in Rhineand forced evacuation of several Westwall blockhouses
opposite Strasbourg. They also caused the Moselle to rise to a level
eleven feet above previousweek’s level. The Blies and other
small streams flowing into the Saar River were flooded and the terrain
alreadybadly pocked by artillery firesin Monday’s bitter fighting, was
covered with water holes”. (NYT, 18 Oct. 1939).
England recorded rainfall of more than three times above average
inOctober 1939. Greenwich saw a higher rainfall only in 1888, and before
that in 1840.
Greenwich total for October (6.16 in.) and November (4.13 in.) together
–10.29 inches – was the highest ever since recordinghad begun at
Similar conditions had been observed at Camden Square (London), where
hours of rainfall are recorded as follows: October 77.3 h.,
November 96.7 h. These were 50 hours higher than the
also reported rainsthroughout the month ofOctober 1939. (NYT, 2
Nov. 1939). Similar conditionpresumably prevailed in Belgium and
Northern France as well. In January 1940 NYT correspondent G. H.
Archambault reported while staying with the French Armies: ”the
autumn of 1939 was one of the wettest known”. (NYT, 26 Jan. 1940).
1939 – Rain Spares France – At least for now
continued to shell Forbach. Artillery hammered as forcefullyas wet
weather impeded action by infantry”, (NYT, 06 Nov. 1939). Another
headline of the NYT (16 Oct. 1939) reads: “French Still Wait for
Reich’s Attack – Rain Impedes Fighting”.
19th October plan “Yellow” for the invasion of France was
finalised. On 7th November commencement of the invasionplan
was postponed for the first time. A Blitzkrieg was not advisable with
‘General Mud’ in company. Hitler wanted to go aheadand would have
sent the Wehrmacht across the boarders in late 1939, but for excessively
wet autumn weather conditionsmade even Hitler think twice.
November 1939 weather conditions were not much better than in October.
In general it was a bit too warm and too wet, 200% and moreof normal for
the season, inHannover, Aachen, Kassel, Frankfurt a. M., Magdeburg, Ulm,
November 19/20, 1939; The Rhine had been rising again and there was
heavy flooding in Switzerland.. (NZZ, 20 Nov. 1939); Heaviest flooding
of rivers in Belgium and Holland made navigation impossible.
Further rise of water was expected. (NZZ, 29 Nov. 1939)
the quantity of rain in East-South-East of Central Europe in late autumn
of 1939 was excessive, was confirmed by a NYT report inmid
December: “The waters of the Danube River has begun to recede from the
record December flood level, and the speed of current, caused by swollen
tributaries, relaxed.” (NYT, 13 Dec. 1939).
and Switzerland - December 1939
to be said on the rain making issueinthis chapter. Saxony with
itscapital Dresden had similarautumn rains as in other parts ofGermany.
Snowfallin Finland, close to Russian-Finland war theatre, since end of
November is certainly a factor which should not be ignored. See:
suddenness and extreme of the war winter of1939/40 had been such an
extraordinary meteorological event that everyaspect relating toits rapid
build up should be elaborated and weighed. The atmosphere during
the particularly climatically sensitive autumn months of September to
December in the Northern Hemisphere reacted immediately. Rain thatcame
down in Western Europe as heavy downpoursince the war had started on
September 1st had not been available in the USA during the
corresponding period. While mostly excessive rain occurred in Europe in
October, four weeks later the USA experienced a record dry month with
only 44% precipitation of average for the whole country during November