Thailand has three seasons; the Hot season, the Monsoon (wet) season and the Cool season.
The hot season runs from March to June, with high temperatures and humidity. The average maximum temperature is 33 degrees Celsius, but due to the humidity often feels much hotter. Some respite is found with some rain towards the end of April and start of May, however April is often the hottest month of the year. March marks the start of the low season for tourists visiting the city, and therefore hotels and vacation property rates can be found to be much cheaper than the high season.
The wet season runs from June to October, with September and October being the wettest months. The worst monsoon weather in Pattaya often arrives during early October and the city receives its highest monthly rainfall and some local flooding may occur. Although the rain can be very heavy at these times, and you can witness some fantastic thunder and lightning storms, it usually only lasts a short time and within a few hours the weather will change and sunny and dry weather will once again be here. Temperatures during this season are still hot, with an average high of 31 degrees Celsius, but as with the hot season, the humidity levels can be high making it feel hotter.
The cool season is the best time to visit Pattaya, between November and February, when the weather will be mainly dry and humidity at its lowest annual levels. Average high temperatures in the cool season range from 26-31 degrees Celsius, and with little humidity feels much cooler and more tolerable than the hot and monsoon seasons. During this season there is an average of 12 hours of daylight, with around 8 hours of sunshine per day. This season is the most popular time for tourists to visit the city, therefore average hotel and vacation rental property prices tend to be higher to reflect the demand. It is recommended that you book your accommodation well in advance, especially over the Christmas and western New Year period, as these are ideal times for tourists to visit Pattaya.