It's crowded and more expensive. Low season features wind predominantly from the southwest. Storms which originate in Antarctica, pass by Sumatra on the way to Phuket. There are periods of one or two weeks during which it rains at least a little on most days. These are actually prime kayaking conditions.
Cloudy days are cooler, making paddling more comfortable.
Conditions often change by the hour. We put on sun screen in the morning and watch approaching rain fronts in the afternoon. Click on the button if you want to read more about this historic two country journey. This means that the hotels, vendors, street merchants and everyone else are asking their highest prices. Negotiating is difficult.