Thiland:

Thailand’s popularity as a tourist destination owes a great deal to its benign climate. Thailand predominantly has a tropical wet and dry or savannah climate while the south and the eastern tip of the east have a tropical monsoon climate.

Most of Thailand has three seasons:

The cool dry season from late-November to February. Temperatures in December for Chiang Mai average around 15 Celsius at night, rising to around 28 Celsius during the day with clear sunny skies. Higher up in the mountains, temperatures may drop to near freezing at night. In Bangkok and in the central and northeastern plains of Thailand, midday temperatures during the cool dry season average around 30 Celsius and the humidity is much lower.
The hot dry season from March to May can see daytime temperatures in the mid- to high-30s. This is the time for holding festivals (such as Songkran and Rocket Festival) to mark the coming of the rainy season.
The rainy season from May to October has daytime temperatures in the low-30s with nighttime temperatures in the mid= to high-20s. Some areas have a relatively short rainy season, such as Ko Samui where it is typically only approximately six weeks, starting in October and running to November.[31] Rain showers mainly occur late-afternoon or early-evening. Typically, humidity is high.

Deeper south on the Kra Isthmus with its tropical monsoon climate, daytime temperatures year-round tend to hover around 31 Celsius with only a marked increase in rainfall during the monsoons. The west coast is affected by monsoons from May to October, the southeast coast of the isthmus is affected from October to January.

Maldives:

The Maldives, a tropical paradise of pristine beaches, are an archipelago of 1,192 coral islands grouped into 26 coral atolls (200 inhabited islands, plus 80 islands with tourist resorts) in the Indian Ocean. They lie south-southwest of India and are considered part of Southern Asia. (Source: Wikitravel)

Tourism in Maldives
Tourism is the largest economic industry in the Maldives. A tourist resort in the Maldives consists of an exclusive hotel on its own island, with its population entirely based on tourists and work force, with no local people or houses. These islands developed for tourism are approximately 800 by 200 metres in size and are composed of sand and coral to a maximum height of about 2 metres above the sea. In addition to its beach encircling the island, each island has its own “house reef” which serves as a coral garden and natural aquarium for scuba divers and snorkelers. The shallow water enclosed by the house reef also serves as a large natural swimming pool and protects swimmers from the ocean waves and strong tidal currents outside the

Mauritius

In Mauritius, when we speak of “the north”, Grand Bay is the first thing that comes to mind. Grand Bay, through sustained development, has become the premier tourist destination of Mauritius.

The starting point of nautical trips to the northern islands and other sea activities, Grand Bay has two beaches, one of which is “La Cuvette, a discreet hideaway, where you can still found the rare “tec-tec” hidden in the sand, small white shells that need to be preserved.

Take a walk through the narrow streets behind the main road and enjoy what the small local boutiques have to offer. Known for its wide variety of restaurants and its nightlife, you will immediately be drawn to this charming and exuberant village.

Another picturesque village in the north of Mauritius is Cap Malheureux, with its famous red-roofed church, its view of the northern islands and its important fishing community.

Sri Lankha

In the twelfth century, the explorer Marco Polo wrote that Sri Lanka was the finest island in the whole world. For centuries it had been a tourism destination, particularly for European travelers. Recently, the Sri Lankan Civil War that spanned over 25 years and ended in 2009 has had a negative impact on tourism and the growth of the industry stagnated, however following this era a resurgence in Sri Lanka as a tourist destination has been evident. In 2012, post office worldwide holiday costs barometer named Sri Lanka as the best valued destination for holidays.[1] Tourist arrivals to Sri Lanka exceeded 1.5 million in 2014.