Flooding in Patong
If you have ever been to Patong in the wet season, then you would have encountered some heavy rain and possibly experienced some flooding. When it rains here it pours and it only takes heavy rain for a few hours for Patong to start flooding.Just about anywhere in the low lying areas of Patong will flood if there is enough rain and it can happen so fast, that it can be a bit hard to believe. You could be at the shopping mall or watching a movie or something and when you come out, the streets are flooded. When the streets flood, the water is usually just above ankle deep, but on some occasions it can go as high as knee deep. Once the rain stops, it usually doesn't take long at all for the streets to subside with the flooding, so that's one good thing about flood situation here.

Not only is there the problem of having so many locals and tourists around all the time to make the task of building new pipes almost impossible, you have the roads which are always clogged with traffic. The roads were not built with the intentions of the place becoming so big, so doing any work on infrastructure will cause major traffic jams, as the roads are already overcrowded.
There has been some construction on roads on the outskirts of Patong and this has helped to ease some of the issues of road safety, but there is so much more work that needs to be done on the major areas of Patong.
The wettest time for weather in Phuket is usually around September - October with October being the wettest month. It can rain at any other random time of the year and with the weather patterns the way they are around the world now, it's anyone's guess as to what each month will hold, but on the average, the best time to visit Phuket for good weather is in December.
Will flooding ruin your holiday in Patong?
As mentioned before, when it floods here, the water usually subsides not long after the rain stops and it doesn't flood often enough to effect your holiday. It should also be noted that the wet season has rain in short hard bursts and it almost never rains all day.