I lived in Nonthaburi for a year then almost three years on the south of Phuket near Chalong Bay. The temps stated in the above article are not even close. Thailand has three seasons: Warm and pretty nice. Dry and very hot. 37+ most days and humid as hell. Dry meaning only that it is not pouring rain. Hot and very wet. I have been kayaking on the khlongs and on the Chao Praya River in Bangkok and the heat index has been in excess of 140 F. If, like most people of retirement age, you have had some healthcare adventures the insurance companies will know all about it already. You must fill out the forms honestly and include everything. Don't be tempted not to because you are now in Thailand. You have a tail. It follows you everywhere. What does this mean? Your healthcare policy will have so many exclusions that you are effectively uncovered for anything that is likely to develop. To keep the policy affordable your deductible will be large, very large. As you age out of the system your premiums will climb, not quite exponentially, but it can seem so. You will be paying for all the routine stuff anyway from your pocket. I was paying just under 2,600 usd a year.
I switched from an O-A retirement visa to an O visa which did not require the health insurance policy. Perhaps that will change in the future. In any event, I felt that all the health insurance premium money I gave out was a complete waste. You will have to decide that for yourself but the above rosy picture is painted by someone trying to sell you health insurance. A bit like being in AARP: An insurance company masquerading as an advocacy group for Seniors.