Cheow Lan LakeCheow Lan Lake at a Glance
About Cheow Lan Lake
Cheow Lan Lake, also called the Ratchaprapha Reservoir, is a large freshwater reservoir in Surat Thani province, southern Thailand, created by the construction of the Ratchaprapha Dam. The flooded valley contains dramatic limestone karst towers and forested islets within Khao Sok National Park.
The lake is visited for boat trips, guided canoeing and overnight stays in floating bungalows positioned among limestone islands. The karst peaks rise directly from the water, creating a distinctive landscape of steep cliffs and sheltered coves.
The reservoir formed after the dam was completed in the late 20th century; the inundation created the extensive lake and its isolated limestone islands, which are now framed by protected forest. Visitor facilities and boat operators are concentrated at a few embarkation points outside the park.
The lake lies within the Khlong Saeng valley of Surat Thani province and is administered as part of Khao Sok National Park, in southern Thailand; access is by road from nearby towns and by boat from the lake piers.
- Creation: Formed by the construction of the Ratchaprapha (Cheow Lan) Dam in the late 20th century, creating a large freshwater reservoir with steep limestone islands and forested shores.
- Accommodation and access: Floating raft-house accommodation is a common overnight option on the lake; trips are run by licensed operators from nearby piers.
What to See#
- Ratchaprapha Dam (reservoir dam): A concrete gravity dam on the Khlong Saeng river that created the reservoir; it functions as the lake’s main control structure and is the typical embarkation point for boat trips into the reservoir.
Best Time to Visit Cheow Lan Lake
Best visited in the dry season (Nov-Apr) for calm waters and comfortable access to floating guesthouses; monsoon season offers dramatic scenery but less reliable transport.
Weather & Climate near Cheow Lan Lake
Cheow Lan Lake's climate is classified as Tropical Monsoon - Tropical Monsoon climate with consistently warm temperatures year-round. Temperatures range from 21°C to 33°C. Heavy rainfall (2258 mm/year), wettest in September with a pronounced dry season.
| Month | Comfort | Temp | Feels | Rain | Sky | Humidity | Wind | UV | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | Very Good | 21° - 31° | 26° | 26 mm | partly cloudy | 88% | 1.3 m/s | 1.9 very high | 11.5h |
| February | Excellent | 22° - 32° | 27° | 24 mm | partly cloudy | 86% | 1.0 m/s | 2.3 extreme | 11.7h |
| March | Very Good | 22° - 33° | 31° | 68 mm | partly cloudy | 81% | 1.4 m/s | 2.5 extreme | 12.0h |
| April | Good | 23° - 33° | 32° | 138 mm | overcast | 80% | 1.5 m/s | 2.5 extreme | 12.2h |
| May | Acceptable | 23° - 32° | 32° | 247 mm | overcast | 89% | 1.7 m/s | 2.1 extreme | 12.4h |
| June | Acceptable | 23° - 31° | 31° | 239 mm | overcast | 91% | 1.6 m/s | 2.0 very high | 12.5h |
| July | Acceptable | 23° - 30° | 27° | 261 mm | overcast | 92% | 1.5 m/s | 1.9 very high | 12.5h |
| August | Acceptable | 23° - 30° | 27° | 321 mm | overcast | 91% | 1.4 m/s | 2.0 extreme | 12.3h |
| September | Good | 23° - 30° | 26° | 344 mm | overcast | 92% | 1.1 m/s | 2.0 extreme | 12.1h |
| October | Good | 22° - 30° | 26° | 312 mm | overcast | 92% | 1.2 m/s | 1.9 very high | 11.8h |
| November | Good | 22° - 30° | 26° | 210 mm | overcast | 91% | 1.0 m/s | 1.8 very high | 11.6h |
| December | Very Good | 22° - 30° | 26° | 68 mm | overcast | 90% | 1.8 m/s | 1.7 very high | 11.5h |
How to Get to Cheow Lan Lake
Cheow Lan Lake is reached from Khao Sok town in Surat Thani province. From Khao Sok, travel by car or minivan to the Ratchaprapa Dam (approximately 1-1.5 hours), where longtail boats ferry visitors onto the lake. Many tour operators in Khao Sok arrange transfers and overnight stays on floating raft houses.
Boat schedules and weather can affect access; book transfers with licensed operators in advance.
Tips for Visiting Cheow Lan Lake
- Take a private boat tour onto the lake to see limestone karsts and canoe through quieter coves; park boat operators can be arranged from Khao Sok or Cheow Lan departure points.
- Stay overnight in a floating raft house for the best pre-dawn mist and early-morning bird activity.
- Arrive early in the day to see the lake's limestone cliffs in the best light; afternoon monsoon squalls are common.