If you live in Chiang Mai, you must make peace with the fact that you will live a good portion of your life wet; either from sweat or rain. Apparently, August is monsoon season. It rains often and really hard - which I love. I just throw open the double doors to my balcony (the runners on the door are really smooth, so I actually can throw them open - it's great) and listen.
The beauty of the rain is even worth getting soaked (which happens in about 2 seconds, especially on your motorbike where raindrops somehow seems to track straight towards your underwear). My expensive, high-tech Marmot jacket is no match for this rain, my giant plastic poncho which covers my whole body somehow only fares slightly better.
The rain rolls down off the mountain every afternoon, usually around the hottest part of the day. The top of the mountain will be obscured by clouds and then this white wave just starts coming down in our direction, the wind picks up, and that delicious pre-rain smell floats around.
In addition to the predictable afternoon rain, there are also completely isolated, unpredictable showers. With the sun shining in one corner of the sky, a stealth ninja raincloud can open up and pour buckets on you without a moment's notice, only to disappear within minutes. These are the kind of storms where you can see the edge of the storm - like a wall of rain. All the roads flood and traffic is even worse than it was before. If I've been away from my apartment, I can tell how recently it's rained where I live by how flooded the end of my soi (side street) is. Oh, only 3 inches of water? it must have stopped raining a while ago...