The weather in Russia is by no means something that I would call "small." It helped the Russians defeat Napoleon in 1812. When the Germans invaded, they were

The weather in Russia is by no means something that I would call "small." It helped the Russians defeat Napoleon in 1812. When the Germans invaded, they were ill-prepared as well. They're vehicles couldn't cope with the cold, so in the winter months, they were bombarded by Soviet bombers but couldn't get any of their own planes in the air. They couldn't move vehicles because the ground turns to mud (they ended up using dead bodies to gain traction). At one point, the Germans were very close to Moscow (within visual distance IIRC) when winter hit. That winter, fresh troops from Siberia who were specially trained for winter warfare arrived in Moscow to push the Germans back. I think it's safe to say that the Russian winter prevented the Germans from capturing Moscow that winter. My favorite podcast (Dan Carlin's Hardcore History) covered the eastern front of WWII in a four-part series, titled "Ghosts of the Ostfront": http://bit.ly/W4ig http://bit.ly/W4ig (episodes 27-30). I highly recommend it to anyone that's interested in history. (That's not an affiliate link, btw.)