Back on 25 March, Chris at the blog Charvey in Vietnam announced that the rainy season in southern Viet Nam had arrived. I knew this was premature because the winds hadn't changed yet.
The winds all through the dry season here in southern Viet Nam over the past six months have been from the northeast, east, and southeast. During the monsoon or rainy season, the winds come out of the southwest. This morning, for the first time in six months, the wind has shifted to come from the southwest. The breeze is now blowing from the back of our house to the front rather than the other way as it has for the past six months.
Even though it isn't raining today as I write this posting, I am confident that the summer monsoon has arrived and we will see heavy rains with thunderstorms very shortly -- probably tomorrow.