Gregory LeFever has published this article (plus sources) at his blog Quantum Spirit:
For the first time in 100 years, we’ve just completed an entire month without a single sunspot. And the lack of sunspots could signal a new Ice Age or some other extraordinary climactic conditions on Earth.
According to data from UCLA’s Mount Wilson Observatory, the last time this happened was in 1913. When the sun is active, there are easily 100 or more sunspots in a month. While there’s an 11-year cycle of diminished sunspots, the current lack has scientists puzzled.
So far this year, the average number of sunspots per month has been three. August had none.