Sam Roi Yot weather in January

In January, Sam Roi Yot sees average daytime highs of 30°C and overnight lows near 21°C, with 29 mm of rain across 4.7 wet days and about 11.4 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 49% of the time in January, and the air most often feels muggy.

Daylight stretches from about 11 h 18 min at the start of January to 11 h 30 min by month's end. Set against the rest of the year, January is Sam Roi Yot's 2nd-clearest and 8th-windiest month. For the whole year in context, see Sam Roi Yot's year-round climate.

Daytime high
30°
9th warmest
Overnight low
21°
1st coldest
Rainfall
29 mm
4.7 wet days
Daylight
11 h 24 min
6:49 AM – 6:10 PM
Cloud cover
45%
2nd clearest
Wind
7 km/h
8th windiest
Solar energy
5.18 kWh/m²
Travel score
5.7
out of 10

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical January day in Sam Roi Yot reaches about 30°C in the afternoon and slips back to 21°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 32°C. Set against its neighbours, January runs about 1°C warmer than December and about 2°C cooler than February.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13021
23021
33021
43021
53021
63021
73021
83021
93021
103021
113021
123021
133021
143021
153021
163021
173021
183021
193021
203021
213021
223021
233021
243121
253121
263121
273121
283121
293121
303121
313121

How January really feels in Sam Roi Yot

Once humidity and wind are folded in, January averages 8 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
8
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in January is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Sam Roi Yot weather by month

How January compares with the rest of the year at a glance. January is the 9th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 21°294.711.45.7
Feb32° / 22°184.611.64.8
Mar33° / 23°6810.711.93.5
Apr34° / 25°961712.32.5
May33° / 25°18025.412.62.1
Jun32° / 25°14323.312.72.6
Jul31° / 24°17924.512.62.8
Aug31° / 24°18224.712.42.8
Sep31° / 24°23026.112.12.6
Oct30° / 23°23224.811.73.3
Nov30° / 23°629.711.45.2
Dec29° / 21°163.411.36.2

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 19% of January, with mostly cloudy or overcast conditions the remaining 32%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16535
26535
36634
46634
56634
66535
76535
86634
96634
106535
116535
126634
136634
146535
156634
166634
176634
186634
196733
206733
216832
226832
236931
246931
257030
267030
277228
287327
297327
307426
317525

Chance of precipitation in January

Any precipitation

Sam Roi Yot gets around 29 mm of rain over 4.7 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 15% and peaks near 16% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
111
211
312
412
512
613
713
814
914
1014
1114
1215
1315
1415
1515
1615
1715
1815
1915
2015
2116
2216
2316
2416
2516
2616
2716
2816
2916
3016
3115

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

Most of January feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, January lands in the muggy band about 38% of days. Sticky, muggy-or-worse air turns up on roughly 66% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1413283718
2412283818
3411283819
4311283820
5310283821
6310283822
7210273823
829273824
929263825
1029253726
1129253727
1229243728
1329243729
1429233729
1529233730
1629223730
1729223730
1829213830
1928213831
2028213931
2128203931
2228203931
2327203932
2427203932
2527203933
2627203833
2726203833
2826203834
2926203834
3026203734
3127203734

Wind in January

Winds average 7 km/h in January.

Across January, daily wind ranges from about 7 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 11 h 18 min at the start of January to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over January. Sunrise moves from 6:45 AM to 6:50 AM, and sunset from 6:02 PM to 6:18 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.36:456:02
211.36:456:03
311.36:466:03
411.36:466:04
511.36:466:04
611.36:476:05
711.36:476:06
811.36:476:06
911.36:486:07
1011.36:486:07
1111.36:486:08
1211.36:486:08
1311.36:496:09
1411.36:496:09
1511.36:496:10
1611.46:496:10
1711.46:496:11
1811.46:506:11
1911.46:506:12
2011.46:506:12
2111.46:506:13
2211.46:506:13
2311.46:506:14
2411.46:506:14
2511.46:506:15
2611.46:506:15
2711.46:506:16
2811.46:506:16
2911.46:506:17
3011.46:506:17
3111.56:506:18

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 5.18 kWh/m².

For context, solar energy here swings from a low near 4.19 kWh/m² to a high of 6.11 kWh/m² in April across the year — January's 5.18 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.1Bright
25.1Bright
35.1Bright
45.1Bright
55.1Bright
65.1Bright
75.1Bright
85.1Bright
95.1Bright
105.1Bright
115.1Bright
125.1Bright
135.1Bright
145.1Bright
155.2Bright
165.2Bright
175.2Bright
185.2Bright
195.2Bright
205.2Bright
215.3Bright
225.3Bright
235.3Bright
245.3Bright
255.3Bright
265.3Bright
275.4Bright
285.4Bright
295.4Bright
305.4Bright
315.5Bright
Planning a trip in January

Hazard calendar for Sam Roi Yot

In seasonPeak

None of Sam Roi Yot's seasonal hazards are active in January. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Sam Roi Yot sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.

Sam Roi Yot's rainy season runs May–October, when most of the year's rain falls.

Cyclone
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is January a good time to visit Sam Roi Yot?

Our two travel scores rate January for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.7
Sightseeing
2nd-best month of the year
7.9
Beach & pool
2nd-best month of the year

January is a reasonable time to visit Sam Roi Yot for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Sam Roi Yot in January

From January's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In January, Sam Roi Yot sees daytime highs around 30°C and nights near 21°C. Pack light clothes. Worth having: sun protection. About 5 days see rain.

light clothessun protection

Sea temperature near Sam Roi Yot in January

The nearest coast averages about 27°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 30 km away) is warmest in May at about 30°C and coldest in January near 27°C.

The water stays above 20°C all year — warm enough for a swim any month.

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb28Warm
Mar29Tropical
Apr30Tropical
May30Tropical
Jun30Tropical
Jul30Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Sam Roi Yot in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Sam Roi Yot peaks around August 16 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 23 at about 9 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 16UV 14Nov 23UV 9
UV index (midday)Level
Jan9Very high
Feb10Extreme
Mar12Extreme
Apr12Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep12Extreme
Oct11Extreme
Nov9Very high
Dec9Very high

Air quality in Sam Roi Yot in January

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where January falls, not just the annual average.

Air quality in Sam Roi Yot is worst in April — around 26 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (September, 11 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateApr 1025 µg/m³Sep 1211 µg/m³
PM2.5 (µg/m³)Level
Jan24Moderate
Feb24Moderate
Mar25Moderate
Apr26Moderate
May16Moderate
Jun12Moderate
Jul13Moderate
Aug12Good
Sep11Good
Oct14Moderate
Nov19Moderate
Dec20Moderate
Location & terrain

Where is Sam Roi Yot?

Sam Roi Yot sits at 12.3°N, 99.9°E, 17 m above sea level, in Thailand. The nearest listed city is Pran Buri, 13 km away.

PhetchaburiKhao Yoi

Topography around Sam Roi Yot

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Sam Roi Yot.

Within 3 km, the terrain around Sam Roi Yot has only modest variations in elevation — a maximum elevation change of 144 m around an average of 12 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 573 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,303 m.

The land around Sam Roi Yot is covered by trees (47%) and grassland (29%) within 3 km, trees (57%) within 16 km, and trees (56%) and water (35%) within 80 km.

3 km
144 m
16 km
573 m
80 km
1,303 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
January weather nearby: Pran Buri 13 km · Kui Buri 21 km · Hua Hin 35 km · Prachuap Khiri Khan 51 km · Cha-am 60 km · Tha Yang 76 km · Phetchaburi 94 km · Khao Yoi 108 km

Thailand travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 31% of US
price level, 2025
GDP per capita
$8,057
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
4.8
per 100k, 2011
Road deaths
32.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 402
Religion
Buddhist 93%Muslim 5%Christian 1%other 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Sam Roi Yot (12.2708°, 99.872°, elevation 17 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).