Climate and monthly weather forecast
Tainan, Taiwan

Tainan, Taiwan, possesses a tropical monsoon climate, referred to as Am under the Köppen climate classification. This coastal city resides close to the Tropic of Cancer, exposing the region to high humidity and temperatures consistently above 20°C (68°F) throughout the year.

A salient feature of Tainan's weather patterns is its heavy rainfall, markedly present during the monsoon months between May and September. During this period, rainfall in millimetres surges from 80mm (3.15") in April to a significant 174mm (6.85") in May, reaching a peak of 395mm (15.55") in August. Furthermore, rainfall days increase from an average of 7.2 in April to a substantial 15.3 in August. This season is characterized by high humidity levels, rising from 76.8% in April to as high as 79.7% in August.

Temperature patterns also exhibit variability throughout the year. While the differential between the mean high and low temperatures remains within 8 to 10°C (50°F) per month, overall, the fluctuation between the highest and lowest monthly temperatures is significant, from 22.9°C (73.2°F) in January to 32.9°C (91.2°F) in July. Simultaneously, sea temperatures stream from a minimum 23.3°C (73.9°F) in January to a high of 29.2°C (84.6°F) in August, offering an inviting environment for water activities for most of the year.

Daylight hours marginally oscillate from 10.7 hours in December to 13.5 hours in June, corresponding closely to the change in seasons. Correspondingly, sunshine hours have a minor variation from 5.6 to 6.8 hours per day while UV index, a critical determinant of skin health, oscillates between 6 and 12 throughout the year.

The best time to visit Tainan aligns closely with the dry months when the city experiences lower rainfall days and amounts. From October to February, rainfall remains well below 100mm (3.94"), reducing the likelihood of weather-induced disruptions. The temperature is relatively mild during this time, ranging from 24.1°C (75.4°F) in December to 31.3°C (88.3°F) in May. Sea temperatures retain warmth, encouraging water-related activities ranging between 24.8°C (76.6°F) in December to 27.7°C (81.9°F) in October.

The most challenging period to visit Tainan would coincide with the monsoon months between May to September. During this time, high rainfall, reaching up to 395mm (15.55") in August and increased rainfall days peaking to 15.3 in August, coupled with high humidity levels, may impact outdoor activities and overall comfort.

Spring invariably paves the way for the warmer months in Tainan with temperature highs progressively escalating from 26.4°C (79.5°F) in March to 31.3°C (88.3°F) in May. Correspondingly, the minimum temperature swells from 17.5°C (63.5°F) to 24.1°C (75.4°F). Rainfall patterns show an upward trend from 39mm (1.54") in March to 174mm (6.85") in May, as the season transitions towards the monsoon.

Summer in Tainan, from June through August, sees the highest temperatures. Highs peak at 32.9°C (91.2°F) in July while the lows never fall beneath 26°C (78.8°F). It's the wettest time of the year as well with rainfall topping at 395mm (15.55") in August. Along with the abundant rainfall, humidity levels rise, peaking at 79.7% in August.

The autumn months of September through November witness a decline in rainfall, from 178mm (7.01") in September to 17mm (0.67") in November. Simultaneously, temperatures gradually cool with highs falling from 32°C (89.6°F) to 27.7°C (81.9°F) and lows moderating from 25.3°C (77.5°F) to 19.6°C (67.3°F).

Winter temperatures in Tainan remain mild, with highs falling from 24.1°C (75.4°F) in December to 22.9°C (73.2°F) in January, and lows moderating between 15.6°C (60.1°F) and 14.1°C (57.4°F). Rainfall remains at its lowest during this season, simultaneously seeing the least daylight and sunshine hours, amounting to 10.7 hours and 5.6 hours, respectively, in December.

Starting the year off on a mild note, Tainan, Taiwan enjoys a fairly comfortable January. Historically, the temperatures are neither too hot nor too cold, providing a nice respite from the extremes of the summer and winter months. Weather in January »

Following January, February brings about a mild increase in all weather parameters. The city begins to gradually warm, though temperatures remain relatively mild. Rainfall in Tainan sees a noteworthy increase during this month, with precipitation levels rising to 28mm (1.1"). Weather in February »

As spring officially arrives, the weather in Tainan undergoes further changes. With each passing day, the city emerges from its winter quiet, transitioning to more active weather patterns. One of the most salient characteristics of March is its increase in rainfall to 39mm (1.54"), indicating the city's shift towards its rainier season. Weather in March »

April in Tainan is when the warmer weather truly sets in. It is during this month that the city sees some notable departures from the milder conditions of the preceding months. Rainfall experiences a dramatic surge in April, rising to 80mm (3.15") and marking the onset of the wetter phase of the year. Weather in April »

Onto May, the weather in Tainan takes a decisive turn towards the typical tropical climate. The days get longer and the UV index continues to rise, showcasing the increased presence of sunlight. The standout characteristic of May resides in its heavy rainfall. Weather in May »

June welcomes the peak of the wet season in Tainan, with heavy showers and overcast days being the norm. The weather parameters clearly communicate the onset of this season, which the city adapts to with remarkable resilience. Notably, June experiences an impressive increase in rainfall, reaching a high point of 372mm (14.65") for the year. Weather in June »

July continues the trend set by June, with heavy rainfall, high humidity, and high temperatures being the defining characteristics. Tainan's weather during this period clearly embodies the traits of a tropical rainforest climate. A high rainfall is an integral part of July's weather profile, with the city receiving on average 358mm (14.09") of rain. Weather in July »

The month of August represents the tail end of the wet season in Tainan. Although rainfall remains heavy and the city continues to experience high levels of relative humidity, subtle shifts can be observed in the weather parameters towards the end of the month. Weather in August »

September in Tainan typically sees the end of the wet season, ushering in a period of transition towards drier months. The city witnesses a gradual decline in rainfall, dropping to an average of 178mm (7.01"). This, however, does not translate into a stark drop in humidity or temperatures, which remain quite high. Weather in September »

October brings with it a significant change in Tainan's weather. The city begins to dry out and there is a noted drop in rainfall compared to the preceding months. With merely 28mm (1.1") of precipitation and marginally shorter days, October is quite a contrast to the wet and humid preceding months. Weather in October »

In November, Tainan experiences further steps towards the cooler and drier period of the year. The city sees a considerable drop in rainfall, down to just 17mm (0.67"). November is characterized by shorter days, reduced sunlight hours, and a sharp decrease in the UV index. Weather in November »

December closes out the year in Tainan on a relatively dry note, with the city experiencing the lowest rainfall of the year at 14mm (0.55"). The month is characterized by shorter daylight hours, fewer sunshine hours, and a further decrease in the UV index. Weather in December »