Khao Yoi weather in September

In September, Khao Yoi sees average daytime highs of 32°C and overnight lows near 25°C, with 212 mm of rain across 24.9 wet days and about 12.1 hours of daylight. It is the 8th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 2% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 18 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Khao Yoi's 9th-clearest and 12th-windiest month. For the whole year in context, see Khao Yoi's year-round climate.

Daytime high
32°
8th warmest
Overnight low
25°
7th coldest
Rainfall
212 mm
24.9 wet days
Daylight
12 h 06 min
6:13 AM – 6:17 PM
Cloud cover
87%
9th clearest
Wind
6 km/h
12th windiest
Solar energy
4.36 kWh/m²
Travel score
2.5
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 32°C through the month.

A typical September day in Khao Yoi reaches about 32°C in the afternoon and slips back to 25°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 33°C. Set against its neighbours, September runs on par with August and about 1°C warmer than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13225
23225
33225
43225
53225
63225
73225
83225
93225
103225
113225
123225
133225
143225
153225
163225
173225
183225
193225
203125
213125
223125
233125
243125
253125
263125
273125
283125
293125
303125

How September really feels in Khao Yoi

Once humidity and wind are folded in, September averages 30 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
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

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

Khao Yoi weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 21°132.411.35.9
Feb32° / 23°122.411.64.8
Mar34° / 24°477.611.93.4
Apr35° / 26°7912.812.32.3
May34° / 26°14523.112.62.0
Jun33° / 26°12421.112.82.4
Jul32° / 26°14922.512.72.6
Aug32° / 25°15923.912.42.6
Sep32° / 25°21224.912.12.5
Oct31° / 24°19121.511.73.4
Nov31° / 23°476.511.45.1
Dec30° / 22°11211.26.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 2% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 6% of September, with mostly cloudy or overcast conditions the remaining 92%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1694
2694
3793
4793
5793
6793
7793
8793
9793
10694
11694
12694
13694
14694
15694
16793
17793
18793
19892
20892
21892
22991
23991
24991
251090
261090
271090
281090
291189
301387

Chance of precipitation in September

Any precipitation

Khao Yoi gets around 212 mm of rain over 24.9 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 84% and peaks near 87% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
181
281
381
481
581
681
781
881
982
1082
1182
1283
1383
1484
1584
1684
1785
1885
1985
2086
2186
2286
2386
2486
2587
2687
2787
2887
2987
3087

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 50% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
16634
26634
36535
46436
56436
66337
76238
86139
96040
105941
115842
125743
135545
145446
155248
165149
174951
184753
194654
204456
214258
224060
233961
243862
253664
263565
273565
283466
293466
303367

Wind in September

Winds average 6 km/h in September, the calmest month.

Across September, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 18 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 24 minutes over September. Sunrise moves from 6:13 AM to 6:13 AM, and sunset from 6:28 PM to 6:07 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.36:136:28
212.26:136:27
312.26:136:27
412.26:136:26
512.26:136:25
612.26:136:25
712.26:136:24
812.26:136:23
912.26:136:22
1012.16:136:22
1112.16:136:21
1212.16:136:20
1312.16:136:19
1412.16:136:19
1512.16:136:18
1612.16:136:17
1712.16:136:16
1812.06:136:16
1912.06:136:15
2012.06:136:14
2112.06:136:13
2212.06:136:13
2312.06:136:12
2412.06:136:11
2512.06:136:10
2611.96:136:10
2711.96:136:09
2811.96:136:08
2911.96:136:08
3011.96:136:07

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.36 kWh/m².

For context, solar energy here swings from a low near 4.33 kWh/m² to a high of 6.16 kWh/m² in April across the year — September's 4.36 kWh/m² sits near the bottom.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.4Bright
34.4Bright
44.4Bright
54.4Bright
64.4Bright
74.4Bright
84.4Bright
94.4Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.3Bright
174.3Bright
184.3Bright
194.3Bright
204.3Bright
214.3Bright
224.3Bright
234.3Bright
244.3Bright
254.3Bright
264.3Bright
274.3Bright
284.3Bright
294.3Bright
304.3Bright
Planning a trip in September

Hazard calendar for Khao Yoi

In seasonPeak

In September, Khao Yoi sits inside its cyclone and rainy season season. The full year is below, with each hazard's peak months called out.

Khao Yoi sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.

Khao Yoi'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 September a good time to visit Khao Yoi?

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

2.5
Sightseeing
9th-best month of the year
3.9
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Khao Yoi.

What to pack for Khao Yoi in September

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

In September, Khao Yoi sees daytime highs around 32°C and nights near 25°C. Pack light clothes and rain gear. About 25 days see rain.

light clothesrain gear

Sea temperature near Khao Yoi in September

The nearest coast averages about 29°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 35 km away) is warmest in May at about 31°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
May31Tropical
Jun30Tropical
Jul30Tropical
Aug30Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Khao Yoi in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Khao Yoi peaks around August 16 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 14Jan 1UV 9
UV index (midday)Level
Jan9Very high
Feb9Very high
Mar13Extreme
Apr12Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep12Extreme
Oct10Extreme
Nov9Very high
Dec9Very high

Air quality in Khao Yoi in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Khao Yoi is worst in February — around 61 µg/m³ PM2.5 (unhealthy), about 2.6× the cleanest month (August, 24 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyPoorModeratePoorFeb 1861 µg/m³Aug 1024 µg/m³
PM2.5 (µg/m³)Level
Jan58Unhealthy
Feb61Unhealthy
Mar60Unhealthy
Apr47Poor
May33Moderate
Jun24Moderate
Jul24Moderate
Aug24Moderate
Sep29Moderate
Oct46Poor
Nov48Poor
Dec48Poor
Location & terrain

Where is Khao Yoi?

Khao Yoi sits at 13.2°N, 99.8°E, 13 m above sea level, in Thailand. The nearest listed city is Phetchaburi, 19 km away.

Topography around Khao Yoi

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Khao Yoi.

Within 3 km, the terrain around Khao Yoi has only modest variations in elevation — a maximum elevation change of 82 m around an average of 11 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 564 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,498 m.

The land around Khao Yoi is covered by cropland (44%) and grassland (24%) within 3 km, trees (31%) and cropland (30%) within 16 km, and trees (50%) and water (25%) within 80 km.

3 km
82 m
16 km
564 m
80 km
1,498 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
September weather nearby: Phetchaburi 19 km · Samut Songkhram 27 km · Tha Yang 33 km · Ratchaburi 33 km · Damnoen Saduak 34 km · Chom Bueng 49 km · Ban Phaeo 50 km · Photharam 50 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 Khao Yoi (13.2402°, 99.8243°, elevation 13 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).