Last updated: August 27, 2025
May in Ko Samui, Thailand offers a tropical climate characterized by warm temperatures and notable humidity. With a maximum temperature reaching 32°C (89°F) and an average of 28°C (84°F), visitors can expect a pleasant atmosphere despite occasional rain. The month sees minimum temperatures around 26°C (79°F), ensuring comfortable evenings. However, be prepared for significant rainfall, totaling 126 mm (5.0 in) over approximately 22 days, making it one of the wetter months of the year. With humidity levels hovering around 77%, the island retains its lush greenery, creating a vibrant backdrop for those looking to explore or relax in this tropical paradise.
May in Ko Samui marks a beautiful transition into the warmest part of the year. As temperatures rise, minimums settle around 26°C (79°F), while averages reach a comfortable 28°C (84°F). The peak temperatures can climb to 32°C (89°F), making it an enticing month for beach lovers and sun seekers. This steady warmth, combined with a gradual increase from the previous months, indicates a summer season in full swing. The weather is ideal for vibrant outdoor activities or simply relaxing by the tropical shores, albeit with the occasional hint of humidity. As May unfolds, it’s the perfect time to embrace all that this island paradise has to offer.
May in Ko Samui typically marks a transition into the wet season, with precipitation totaling 126 mm (5.0 in) over the month. This level of rainfall is accompanied by a notable increase in rainy days, with 22 days of precipitation, making it one of the wetter months of the year. Compared to April, which also experienced significant rainfall (144 mm), May sees a slight decrease but still sets the stage for the more intense rainfalls of the following months. As the island gears up for the peak of the monsoon season, travelers should prepare for the lush, vibrant landscapes that emerge from this seasonal shift, all while keeping an umbrella handy!
In May, humidity in Ko Samui, Thailand begins to rise noticeably, reaching 77%, a jump from the lower levels of the preceding months, which averaged around 68% to 69%. This increase foreshadows the arrival of the wetter months ahead, with June and July peaking at a high 86%, and August reaching an even more oppressive 88%. The trend highlights a humid tropical climate that becomes increasingly pronounced as the year progresses, creating a lush environment ideal for travelers seeking a vibrant escape, though it also calls for preparations against the tropical heat and moisture.
In May, Ko Samui experiences an impressive UV Index of 14, solidifying its position in the extreme exposure category. With a consistent burn time of only 10 minutes, sunlight can be quite intense during this month, just as it has been since the start of the year. Although slightly lower than the peak 15 recorded in March and April, May's UV levels remain remarkably high, continuing the trend of strong sun exposure typical of this tropical paradise. Visitors should take care to protect their skin, just like they would throughout the year. For more detailed insights on UV levels, check out the Ko Samui UV Index.
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May in Ko Samui shines brightly, boasting 331 hours of sunlight, making it one of the sunniest months of the year. This delightful weather follows April's 318 hours, showcasing a trend of increasing daylight as the year progresses. As spring transitions into early summer, the sunny days continue into June, albeit slightly lessening with 308 hours. The overall pattern reflects a tropical climate where the months leading up to the summer often provide ample sunshine. For sun-seekers and beach lovers, May offers a perfect blend of warmth and brightness, setting the stage for the vibrant summer season ahead.
When considering the likelihood of sunny weather in Ko Samui, Thailand, May presents a notable dip in sun exposure, with just 21% chance of clear skies. This decrease follows a trend of fluctuating weather patterns, where the sun shines brightest in the earlier months, peaking at 58% in February. As the seasons progress into April, the probability remains relatively stable at 32%, but then takes a downward turn in May, leading into the rainy season. Interestingly, this trend of diminishing sun continues into the following months, with June and July seeing chances of sunshine drop further to 22% and 18%, respectively. Therefore, travelers intent on soaking up the sun may want to rethink their plans for May, as this month marks a shift towards less predictable weather in this tropical paradise.
In Ko Samui, Thailand, daylight duration exhibits a pleasant rhythm throughout the year. Starting off in January and February, the island enjoys 11 hours of sunlight, offering a cozy atmosphere. As the days progress into March and April, daylight increases to 12 hours, hinting at the approaching summer. This extended daylight continues into May, providing ample time for exploration and relaxation. The consistent 12 hours of daylight remains steady until September, allowing visitors to fully embrace the vibrant tropical life. As October approaches, daylight begins to wane again to 11 hours, leading the way into a more tranquil end of the year during November and December. This consistent pattern of light makes Ko Samui a delightful destination year-round, perfect for any traveler seeking a sun-kissed getaway.
As May unfolds in Ko Samui, Thailand, the island experiences a gentle breeze with an average wind speed of 4.0 m/s (9 mph), presenting a mild contrast to the preceding months. While April boasts the calmest winds at 3.5 m/s (8 mph), May signals a slight uptick, reflecting a gradual transition toward the breezier summer months. Following this pattern, June and July ramp up the winds to 4.8 m/s and 5.4 m/s respectively, enticing beachgoers and water sports enthusiasts alike. This uptick illustrates a notable trend: as the early summer approaches, so does a refreshing shift in the wind, creating a perfect atmosphere for outdoor adventures while still allowing for serene moments of relaxation under the sun.
Weather in Ko Samui varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Ko Samui, focusing on differences in temperature, rainfall, humidity, and UV levels.
In May, temperatures reach a minimum of 26°C (79°F) and can peak at 32°C (89°F), with an average temperature of 28°C (84°F). The month is characterized by significant rainfall, totaling 126 mm (5.0 in) over about 22 days, and humidity is relatively high at 77%. In contrast, January offers slightly cooler temperatures, with a minimum of 24°C (76°F) and a maximum of 28°C (83°F), averaging 27°C (80°F). Although January sees more total precipitation at 144 mm (5.7 in), it spreads over just 13 days, resulting in lower humidity at 72%. For more detailed insights, check out Ko Samui weather in January.
When comparing the weather in May and February, May tends to be significantly warmer and wetter. In May, temperatures range from a minimum of 26°C (79°F) to a maximum of 32°C (89°F), with an average of 28°C (84°F). In contrast, February experiences slightly cooler temperatures, with lows of 25°C (77°F) and highs reaching only 28°C (83°F), averaging 27°C (81°F). Additionally, May sees substantially higher precipitation, with 126 mm (5.0 in) of rain over 22 days, compared to February's 39 mm (1.5 in) over just 8 days. This leads to a noticeably higher humidity level in May at 77%, compared to February's 68%. For more detailed insights, you can visit Ko Samui weather in February.
In comparing the weather between March and May, March offers slightly cooler temperatures with a minimum of 25°C (78°F) and a maximum of 30°C (86°F), while May sees higher temperatures ranging from a minimum of 26°C (79°F) up to a maximum of 32°C (89°F). Additionally, May experiences significantly more rainfall, totaling 126 mm (5.0 in) over 22 days, compared to March's 38 mm (1.5 in) spread over just 7 days. Humidity levels are also higher in May at 77%, compared to March's 68%. For a deeper dive into the specifics, you can check out Ko Samui weather in March.
In comparing the weather of May and April, we find that both months have similar average temperatures, with May slightly warmer at an average of 28°C (84°F) compared to April’s 28°C (83°F). However, May tends to exhibit a higher minimum temperature of 26°C (79°F) against April's 25°C (77°F). Precipitation levels are noteworthy; May experiences 126 mm (5.0 in) of rainfall over 22 days, whereas April has 144 mm (5.7 in) over 15 days. Additionally, humidity rises in May to 77%, compared to April's 69%. For more detailed insights, you can visit Ko Samui weather in April.
In comparing the weather between May and June, both months exhibit similar temperature patterns, with minimums of 26°C (79°F), average highs of 28°C (84°F), and maximums reaching up to 32°C (89°F). However, June tends to be drier, receiving only 96 mm (3.8 in) of precipitation over 18 days, compared to May’s 126 mm (5.0 in) over 22 days. Additionally, while humidity rises slightly in June to 86%, it remains at a high level in May at 77%. For more detailed information, you can refer to Ko Samui weather in June.
When comparing the weather in May and July, both months showcase warm temperatures with high humidity levels. In May, the minimum temperature sits at 26°C (79°F), with an average of 28°C (84°F) and a maximum of 32°C (89°F). This month experiences more precipitation, totaling 126 mm (5.0 in) over 22 days, resulting in a humidity level of 77%. Conversely, July has similar temperature patterns, with a minimum of 26°C (80°F), an average of 28°C (83°F), and a maximum of 31°C (88°F). However, July is slightly drier, with a total precipitation of 79 mm (3.1 in) over 17 days, but with higher humidity reaching 86%. For a more detailed look at the weather conditions, you can check Ko Samui weather in July.
In May, the weather is characterized by slightly warmer temperatures with an average of 28°C (84°F) and maximums peaking at 32°C (89°F), accompanied by a significant amount of precipitation totaling 126 mm (5.0 in) over 22 days, resulting in a humidity level of 77%. In contrast, August offers similar temperature ranges, with minimums and averages remaining at 26°C (79°F) and 28°C (83°F), but with a drop in rainfall to 80 mm (3.1 in) over 18 days and an increase in humidity to 88%. This comparison highlights a wetter May with more rainfall, while August presents a more humid atmosphere with slightly less rain. For more details about the weather in August, you can check Ko Samui weather in August.
In May, the weather features warm temperatures, with a minimum of 26°C (79°F) and an average of 28°C (84°F), peaking at a maximum of 32°C (89°F). However, it also brings significant rainfall, with 126 mm (5.0 in) of precipitation spread over 22 days and an average humidity of 77%. In contrast, September maintains a similar minimum temperature of 26°C (78°F) and an average of 28°C (82°F), but the maximum temperature is slightly lower at 30°C (86°F). Rainfall increases to 151 mm (5.9 in) over 21 days, contributing to a higher humidity level of 87%. For more details on September weather, visit Ko Samui weather in September.
In comparing the weather between May and October, we can see some notable differences. May tends to be slightly warmer, with average temperatures around 28°C (84°F) and maximums reaching 32°C (89°F). In contrast, October features cooler temperatures, averaging 27°C (81°F) with a maximum of 30°C (85°F). However, October experiences significantly higher precipitation levels, with 241 mm (9.5 in) over 28 days, compared to May’s 126 mm (5.0 in) across 22 days. Additionally, humidity levels rise in October, reaching 86%, while May's humidity sits at 77%. For more detailed information, check out Ko Samui weather in October.
In comparing the weather of May and November, we observe notable differences in temperature and precipitation. May typically enjoys warmer temperatures, with average highs reaching 32°C (89°F), while November's temperatures are slightly cooler, averaging a maximum of 29°C (85°F). However, November is characterized by significantly higher precipitation, with 336 mm (13.2 in) of rain spread over 24 days, compared to May's 126 mm (5.0 in) over 22 days. Additionally, November exhibits higher humidity levels at 87%, compared to May’s 77%. For a more detailed look at how weather conditions differ in November, you can check out Ko Samui weather in November.
In comparing the weather of May and December, May tends to be warmer with average temperatures reaching 28°C (84°F) and maximums peaking at 32°C (89°F). It experiences a significant amount of rainfall, averaging 126 mm (5.0 in) over 22 rainy days and maintaining a humidity level of 77%. In contrast, December offers slightly cooler temperatures, with an average of 27°C (80°F) and a maximum of 29°C (84°F). However, it has higher precipitation, totaling 207 mm (8.1 in) over 17 days, along with increased humidity at 83%. For a detailed look at December weather conditions, you can refer to Ko Samui weather in December.
As May arrives in Ko Samui, the island transitions into a wetter season, with increased humidity and frequent rainfall that sets it apart from the drier months preceding it. Temperatures remain warm, while the average humidity level hovers around a sultry 77%, creating a tropical atmosphere that's perfect for those who enjoy lush landscapes and vibrant nature. Despite the rain, many travelers find the lush scenery and the quieter atmosphere to be a refreshing change. While outdoor activities may sometimes be interrupted by showers, the island's charm and beauty persist throughout the month. For more insights into the climate in Ko Samui and how it varies throughout the year, check out Ko Samui Climate.