The cheapest time to visit Thailand can vary depending on several factors, including seasonality, holidays, and local events. Generally, the shoulder seasons, which fall between the peak and off-peak seasons, tend to offer lower prices and better deals for travelers. The following periods are typically considered as relatively more affordable times to visit Thailand:

1. Late April to June: This period falls after the peak tourist season, which is usually between December and February. Prices for flights, accommodations, and attractions tend to be lower during this time. However, it’s worth noting that some parts of Thailand may experience higher temperatures and occasional rainfall during this period.
2. September to October: These months are part of the off-peak season due to the monsoon season in Thailand. While it may rain more frequently during this time, the rainfall is usually in short bursts, and there are still plenty of sunny days. Prices for flights and accommodations can be lower, and there may be fewer crowds at popular tourist spots.
3. November: November is considered a transitional month between the wet and dry seasons in Thailand. Prices can be relatively lower compared to the peak season, and the weather is generally pleasant with less rainfall. It’s a good time to visit before the influx of tourists during the December holiday season.

It’s important to keep in mind that even during the cheaper periods, prices can vary depending on specific destinations within Thailand. Major cities and popular tourist areas may still have higher prices compared to more remote or less-visited regions.

Additionally, it’s advisable to book accommodations and flights in advance and compare prices from different providers to secure the best deals. Researching and considering the weather conditions and any potential travel disruptions during the chosen time of visit is also important.

Ultimately, while these periods are generally associated with lower prices, it’s essential to balance cost considerations with personal preferences and the experiences you wish to have while visiting Thailand.