Generally speaking, Thailand is a safe place to go. Yes, there are a few scams here and there but as long as you take the time to read about them beforehand, you’re good.
While you can visit Thailand all year round, avoiding the monsoon season might be smart if much of your holiday plans involve basking in exotic islands. The best time to go to Thailand is December to March (All of Thailand). In a nutshell, the weather in Thailand can be broken down into three parts: Rainy (roughly May-Oct), Cool (Nov–Feb), Hot(March-May). Despite having different seasons, traveling around Thailand is warm, except a few cooler months in Northern Thailand. With that in mind, make sure you bring lots of cool quick dry clothing and well as a scarf or two for visiting temples and other religious sites.
As with most places in the world, there are some common scams and tricks that abound in Thailand’s tourist areas. And, few things can ruin a great day on vacation as fast as realizing you’ve been well and truly conned. Thailand’s laid-back atmosphere and smiling locals can make it easy to fall into a false sense of security. Keep your guard up, though, and maintain a healthy level of skepticism.
While many tourists in Thailand rent scooters to explore, it really may not be the most sensible of moves. Inexperienced riders coupled with Thailand’s terrible road safety records do not go well together. Plus, unless you have a motorbike license from your home country (and, even that’s not a guarantee), you probably won’t be insured. While a small bump can be easy to laugh off, being unable to hike/ swim/snorkel etc. for the rest of your trip really could spoil things. And, that’s if nothing worse happens. If you are adamant about renting a scooter, never, ever ride without a helmet; a full-face helmet is highly recommended. Wear closed footwear and long items of clothing.
220V AC electricity. Power outlets are usually two-prong round or flat sockets. Be sure to pack a universal travel adaptor so you can still use all your electronic gadgets.
Generally speaking, people from the US, UK, and EU passports are given a free 30-day visa when you enter Thailand by air and 15 days if you enter overland. This visa is easily extendable if you want to stay in the country for longer. ASEAN passport holders get a free 30-day visa upon entry (but some aren’t valid for extension). If you want to stay in Thailand for longer, you can look at applying for a tourist visa in any Thai embassy beforehand (this gives you 60 days). Please note that more and more countries in Southeast Asia require you to show proof of onward flights before allowing you to enter the country so make sure you make the necessary booking arrangements.