When should I extend my 60-day tourist visa in Thailand for an additional 30 days?

You can extend your 60-day tourist visa for an additional 30 days at designated immigration offices in Thailand. Major places like Bangkok, Chiang Mai, Phuket, and Buri Ram allow you to extend your visa up to 45 days prior to its expiration, while most other locations permit extensions up to 30 days in advance. It is advisable to extend your visa early, as they will simply add the extra days to your current stamp. Additionally, ensure that your medical insurance covers the extended stay, as proof will be required.