Of course, August often brings bad news for Russia - debt default in 1998, sinking of the Kursk submarine in 2000; terrorist attacks in 2004, and the war with Georgia in 2008. This year, Russia has seen both the highest sustained temperatures and the worse drought in more than a century.
Russia is the world's third largest wheat exporter and the fourth largest grain exporter overall. In most years, the US, Canada, Australia, the EU-27, the former Soviet Union (including three major wheat exporters: Russia, Ukraine, and Kazakhstan), and Argentina account for about 90% of world wheat exports.
So far, the USDA forecasts global wheat supply to be relatively stable, with a good crop in the US offsetting weakness elsewhere. But as we've seen thoughout this crisis, it doesn't take a lot to spook the trading markets.