Precipitation-wise, Beijing is a strange city. Beijing is, in its natural state, a very arid place. So much so that, last winter, I kept track of the number of times it snowed: exactly twice. We often go weeks without a decent rainfall, and when it is that dry, it is painfully dry: grass shrivels, leaves turn brown, and my skin aches for moisture despite the fact that my house came equipped with three humidifiers in addition to the built-in humidifying feature in the air exchange system.

Aridity is not in itself strange; what makes Beijing so strange is the peculiar link between air pollution levels and the timing of the appearance of rainfall.

I’ve written in the past about this city’s air pollution woes (as someone recently put it to me, a smokestack is cleaner than Beijing). And rumour has it that the local government’s best weapon of choice to combat air pollution is precipitation: according to very persistent rumours, clouds in Beijing are regularly seeded so that they release precipitation which temporarily clears away the air pollution.

When I first heard these rumours, I started to pay very close attention to the air pollution-precipitation link, and found a striking pattern: we have a couple of nice, fresh days. Gradually, the air quality drops. It becomes unbearably hazardous. It rains, usually at night. The rain clears the air and we can breathe again. The cycle repeats.

I know this seems like crazy science fiction. But in a country obsessed with stability and control, it is quite feasible to imagine that in Beijing, even the weather is controlled.

What makes this even more crazy is that, according to these rumours, oftentimes the big cloud-seeding guns are brought out at times when air pollution is inconvenient and the city wants to hide its nasty air quality problem show off a little bit. I remember that around the end of September last year, we had a particularly bad stretch of poor air quality. As China’s national day (October 1) approached, coincidentally it began to rain. Just a drizzle here and there, which didn’t have much effect on the pollution. And then, the night before the big day, it rained serious cats and dogs. The next day, the air was beautiful and fresh, just in time for all the press and tourists in town to commemorate the big day. The same thing happened last March during the National People’s Congress, the annual gathering of China’s parliament- the air quality was the best I’ve yet to experience here that week.

Charlotte and I returned from Moscow last week and since then, the air has been seriously awful, so bad that Charlotte has been kept indoors (against her will, that kid is seriously coo-coo for the playground). The past couple of nights, it’s drizzled but the rain hasn’t been enough to wash away the pollution.

But as I write this, one serious storm is occurring outside. Rain is slashing against the windows, lightning brighter than the lights in my room flashes at regular intervals, and the thunder is so loud that it scares me for the first time in my adult life.

And I am thrilled. If it wasn’t 10:00 at night and the end of a long day, I would throw on my rainboots and go play in the rain, rejoicing in the knowledge that, after a downpour like this, tomorrow is guaranteed to be a beautiful day. Charlotte can play her heart out at the playground, I can open the windows and air out my stuffy house, and for a short period of time I can live my life without being constantly conscious of the air I breathe.

Until the pollution builds, and the cycle begins again.