Best time to visit Sur

Re-score for me — drag the dial — every chart recolours live for your heat & sea limits 27°C · sea 29°C
I'm comfortable up to 27°C feels-like
22° heat-averse 30° heat-loving

Default 27 °C is the upper edge of the Holiday Climate Index "ideal comfort" band (Scott, Rutty, Amelung & Tang, 2016). Above this, most warm-tourism travellers report measurable discomfort.

Sea feels bathtub at 29°C
26° strict 31° tolerant

Default 29 °C is the Beach Climate Index "bathtub" line (Morgan et al.) — where the sea stops being refreshing and starts feeling like a warm bath.

Saved to this browser. Changes update the strips below.
Sea temp cold <18° chilly 18–21° ideal 22–26° warm 27–28° bathtub 29–30° too warm ≥31°
Recent · 2020-2024
Interest Google Trends 2021-2025 searches, not arrivals (?)
Sea Nov 2022 – Dec 2024 (?)
Day · avg daily high (?)
Night · avg overnight low (?)
UV index · On a typical day around midday, UV is about this (?)
6891011109910876
On the sunniest 1 in 10 days, UV reaches this — and even higher
791112116
PM2.5 air quality · on a typical day (?)
161715151118251811131715
On the worst 1 in 10 days, PM2.5 reaches this — and even higher
232526242029403017212825
January 10/10 feels 24°C · HCI 99/100
Day 25° · Night 18° 48% humidity 24 km/h wind 2 rain days (18h) 232h sun sea 25°C
Thermal 10
Sky 10
Rain 10
Wind 9

Higher = better, including rain & wind (green = "doesn't hurt the score", not "lots of it").

Compare with another destination

Add as many as you like — stacked below the main strips above. Each row is just the recent-window score strip and (for beach destinations) sea-temperature strip.

Tours in Sur

6 top-rated tours via Viator. Booking links earn this site a commission at no cost to you. Map locations are approximate (centred on Sur).

  1. 1Half Day Highlights Koh Samui Tour4.89★ (1,504)4hfrom $31🔥 Selling fast
  2. 2Koh Samui Custom Sightseeing Tour with Private Guide4.88★ (506)from $169
  3. 3Full Day Ang Thong Islands Luxury Small Group Tour4.87★ (330)7hfrom $139🔥 Selling fast
  4. 4Koh Tao and Koh Nang Yuan VIP Small Group Tour4.85★ (144)from $139🔥 Selling fast
  5. 5Koh Samui Pig Island Snorkeling by Private Longtail Boat5.00★ (1)4hfrom $121
  6. 6Private SpeedBoat Tour to Koh Madsum and Koh Tan5.00★ (3)from $132

Last refreshed 2026-05-30.

Similar climatesDubai92% · Loreto83% · La Gomera76%

Other destinations with the most-alike year-round climate to Sur (apparent temperature, rain hours, sunshine — matched within the same trip-profile). The ±N chip compares each match's typical score for the current month against Sur's. Based on the 2020-2024 climatology, not this year's actual weather.

Month-by-month

Month Temp °C Feels °C Rain days Rain h Rain h/day Humidity Wind km/h Sun h UV Interest Score
Jan 18–25 24 2 18 9.0 48% 24 232 6 Quiet 10
Feb 19–27 26 1 12 12.0 49% 23 228 8 Quiet 10
Mar 22–31 30 1 9 9.0 39% 25 259 9 Quiet 8
Apr 26–35 35 2 16 8.0 38% 24 256 10 Quiet 5
May 29–39 39 1 4 4.0 31% 27 275 11 Quiet 3
Jun 30–40 41 0 0 35% 28 262 10 Quiet 2
Jul 29–38 41 3 30 10.0 45% 28 232 9 Quiet 2
Aug 28–38 40 0 2 41% 28 245 9 Busy 2
Sep 26–37 38 0 3 37% 25 260 10 Moderate 3
Oct 24–34 35 1 12 12.0 42% 22 253 8 Moderate 5
Nov 22–30 31 1 11 11.0 46% 20 236 7 Peak 8
Dec 20–27 26 1 10 10.0 48% 22 232 6 Peak 10

UV Index in Sur by Month

UV index in Sur peaks at 11 (very high) in May, dropping to 6 (moderate) in December. March, April, May, June, July, August, September, October reach very high or extreme levels — apply SPF 50+, wear a hat and protective clothing, and limit direct sun between 11:00 and 17:00.

Best months in detail

January

10/10

18–25°C (feels 24°C) · 2 rain days (18h) · 232 sun hours · 48% humidity · Quiet crowd · UV 6 (moderate) · sunniest 1 in 10 days reach 7 (high)

February

10/10

19–27°C · 1 rain days (12h) · 228 sun hours · 49% humidity · Quiet crowd · UV 8 (high) · sunniest 1 in 10 days reach 9 (very high)

December

10/10

20–27°C · 1 rain days (10h) · 232 sun hours · 48% humidity · Peak crowd · UV 6 (moderate) · sunniest 1 in 10 days reach 6 (high)

Every month

Show the other 9 months in detail

March

8/10

22–31°C (feels 30°C) · 1 rain days (9h) · 259 sun hours · 39% humidity · Quiet crowd · UV 9 (very high)

April

5/10

26–35°C · 2 rain days (16h) · 256 sun hours · 38% humidity · Quiet crowd · UV 10 (very high) · sunniest 1 in 10 days reach 11 (extreme)

May

3/10

29–39°C · 1 rain days (4h) · 275 sun hours · 31% humidity · Quiet crowd · UV 11 (very high) · sunniest 1 in 10 days reach 12 (extreme)

June

2/10

30–40°C (feels 41°C) · 0 rain days (0h) · 262 sun hours · 35% humidity · Quiet crowd · UV 10 (very high) · sunniest 1 in 10 days reach 11 (extreme)

July

2/10

29–38°C (feels 41°C) · 3 rain days (30h) · 232 sun hours · 45% humidity · Quiet crowd · UV 9 (very high)

August

2/10

28–38°C (feels 40°C) · 0 rain days (2h) · 245 sun hours · 41% humidity · Busy crowd · UV 9 (very high)

September

3/10

26–37°C · 0 rain days (3h) · 260 sun hours · 37% humidity · Moderate crowd · UV 10 (very high)

October

5/10

24–34°C · 1 rain days (12h) · 253 sun hours · 42% humidity · Moderate crowd · UV 8 (very high)

November

8/10

22–30°C · 1 rain days (11h) · 236 sun hours · 46% humidity · Peak crowd · UV 7 (high)

Frequently asked questions about visiting Sur

When is the best time to visit Sur?

January is the highest-scoring month (10/10 on the Holiday Climate Index). Typical conditions: 18–25°C (2 rainy days). The top three months by score are January, February, December.

What is the worst time to visit Sur?

August is the lowest-scoring month (2/10, capped by extreme heat). Typical conditions: 28–38°C (0 rainy days).

Is Sur too hot in summer?

9 months (March, April, May, June, July, August, September, October, November) trip the heat deal-breaker in our scoring: apparent temperature crosses the comfort cap, so even with clear skies and low rain the score is held down. Plan around it if heat tolerance is low.

When are crowds lowest in Sur?

Search-interest seasonality (Google Trends 2021-2025) is lowest in January and peaks in November. Interest tracks both in-trip visitors and lead-time planners, so treat it as a "destination is on people's minds" signal rather than literal arrivals.

Which months in Sur have good weather but fewer tourists?

January (climate 10/10, crowd index 0) and February (climate 10/10, crowd index 1) — shoulder months with above-average climate and below-median search-interest. Often the best value-for-weather trade.

What is the UV index in Sur by month?

UV peaks at 11 (very high) in May and is lowest in December at 6 (moderate). Monthly peak values: Jan 6, Feb 8, Mar 9, Apr 10, May 11, Jun 10, Jul 9, Aug 9, Sep 10, Oct 8, Nov 7, Dec 6. March, April, May, June, July, August, September, October reach very high or extreme levels — apply SPF 50+, wear a hat and protective clothing, and limit direct sun between 11:00 and 17:00.

What is the UV index in Sur in May?

May is the peak UV month in Sur, with a daily-peak UV index of 11 (very high). At this level, sunburn can occur in under 20 minutes on unprotected fair skin. Apply SPF 50+, wear protective clothing and a hat, and avoid direct midday sun (11:00–17:00).

How high can UV get in Sur on the sunniest days?

Most days look like the monthly average, but on the sunniest ~1 in 10 days UV climbs higher than the mean suggests. May is the worst case: typical days average UV 11 (very high), but the top 10% of days reach UV 12 (extreme) — and even higher. Months where the sunniest days routinely exceed the typical reading: January, February, April, May, June, December. Plan sun protection for the worst case, not the average.

Is air quality in Sur bad for travelers?

PM2.5 (fine-particle pollution) exceeds the WHO sensitive-group guideline (15 µg/m³) in 12 months: January, February, March, April, May, June, July, August, September, October, November, December. The worst month is July with a typical-day mean of 25 µg/m³ (unhealthy); on the worst 10% of days PM2.5 reaches 40 µg/m³ (hazardous) and higher. People with asthma, heart conditions, or sensitive children may want to avoid these months or limit outdoor activity. Source: CAMS via Open-Meteo.