Rayong weather in September

In September, Rayong sees average daytime highs of 31°C and overnight lows near 26°C, with 301 mm of rain across 26.4 wet days and about 12.1 hours of daylight. It is the 12th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 1% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Rayong's 11th-clearest and 10th-windiest month. For the whole year in context, see Rayong's year-round climate.

Daytime high
31°
12th warmest
Overnight low
26°
7th coldest
Rainfall
301 mm
26.4 wet days
Daylight
12 h 06 min
6:07 AM – 6:11 PM
Cloud cover
89%
11th clearest
Wind
9 km/h
10th windiest
Solar energy
4.49 kWh/m²
Travel score
2.6
out of 10

Rayong is city in Rayong province, Thailand.

Air quality
Elevated
PM2.5 19.2 µg/m³ · 2019
Density
6,297/km²
people per km²
Founded
1917

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical September day in Rayong reaches about 31°C in the afternoon and slips back to 26°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 32°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13126
23126
33126
43126
53126
63126
73126
83126
93126
103126
113126
123126
133126
143126
153126
163126
173126
183126
193125
203125
213125
223125
233125
243125
253125
263125
273125
283125
293125
303125

How September really feels in Rayong

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.

Rayong weather by month

How September compares with the rest of the year at a glance. September is the 12th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°28611.35.1
Feb31° / 24°326.911.64.8
Mar32° / 25°8114.211.94.0
Apr32° / 26°1331912.33.1
May32° / 26°2202512.62.6
Jun31° / 26°21024.512.72.7
Jul31° / 26°2062512.72.8
Aug31° / 26°19624.912.42.8
Sep31° / 26°30126.412.12.6
Oct31° / 25°25623.211.73.1
Nov31° / 24°598.611.44.5
Dec31° / 23°173.411.35.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 5% of September, with mostly cloudy or overcast conditions the remaining 95%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1694
2694
3694
4694
5694
6595
7595
8595
9595
10595
11595
12595
13595
14595
15595
16595
17595
18595
19595
20595
21595
22694
23694
24694
25694
26694
27694
28694
29793
30793

Chance of precipitation in September

Any precipitation

Rayong gets around 301 mm of rain over 26.4 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 89% and peaks near 93% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
182
282
382
483
583
684
785
885
986
1087
1187
1288
1389
1490
1590
1690
1791
1891
1991
2092
2192
2292
2392
2492
2592
2692
2793
2893
2992
3092

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the miserable band about 94% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
1694
2694
3694
4694
5694
6694
7694
8793
9793
10793
11793
12793
13793
14793
15793
16793
17793
18694
19694
20694
21694
22595
23595
24595
25595
26595
27595
28694
29694
30694

Wind in September

Winds average 9 km/h in September.

Across September, daily wind ranges from about 7 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 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 18 minutes over September. Sunrise moves from 6:07 AM to 6:07 AM, and sunset from 6:22 PM to 6:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:076:22
212.26:076:21
312.26:076:21
412.26:076:20
512.26:076:19
612.26:076:19
712.26:076:18
812.26:076:17
912.26:076:16
1012.16:076:16
1112.16:076:15
1212.16:076:14
1312.16:076:14
1412.16:076:13
1512.16:076:12
1612.16:076:11
1712.16:076:11
1812.06:076:10
1912.06:076:09
2012.06:076:08
2112.06:076:08
2212.06:076:07
2312.06:076:06
2412.06:076:06
2512.06:076:05
2611.96:076:04
2711.96:076:03
2811.96:076:03
2911.96:076:02
3011.96:076:01

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.49 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.49 kWh/m² to a high of 5.93 kWh/m² in April across the year — September's 4.49 kWh/m² sits near the bottom.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.6Bright
84.6Bright
94.6Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.4Bright
154.4Bright
164.4Bright
174.4Bright
184.4Bright
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 Rayong

In seasonPeak

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

Rayong sits in the Pacific typhoon belt; the season peaks July–October.

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

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

Is September a good time to visit Rayong?

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

2.6
Sightseeing
11th-best month of the year
3.8
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Rayong.

What to pack for Rayong in September

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

In September, Rayong sees daytime highs around 31°C and nights near 26°C. Pack light clothes and rain gear. About 26 days see rain.

light clothesrain gear

Sea temperature near Rayong 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 14 km away) is warmest in May at about 31°C and coldest in January near 28°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
Jan28Warm
Feb28Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Tropical

UV index in Rayong 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 Rayong peaks around August 16 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 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 14Dec 14UV 9
UV index (midday)Level
Jan9Very high
Feb10Extreme
Mar12Extreme
Apr12Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep12Extreme
Oct10Extreme
Nov9Very high
Dec9Very high

Air quality in Rayong 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 Rayong is worst in January — around 28 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (June, 12 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Rayong's WHO annual average of 19.2 µg/m³.

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateJan 2428 µg/m³Jun 2012 µg/m³
PM2.5 (µg/m³)Level
Jan28Moderate
Feb28Moderate
Mar21Moderate
Apr19Moderate
May15Moderate
Jun12Moderate
Jul13Moderate
Aug12Moderate
Sep15Moderate
Oct22Moderate
Nov22Moderate
Dec21Moderate
Location & terrain

Where is Rayong?

Rayong sits at 12.7°N, 101.3°E, 7 m above sea level, in Thailand. The nearest listed city is Ban Phe, 20 km away.

Topography around Rayong

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

Within 3 km, the terrain around Rayong has only modest variations in elevation — a maximum elevation change of 32 m around an average of 7 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 334 m; within 80 km, large variations in elevation — a maximum elevation change of 1,083 m.

The land around Rayong is covered by artificial surfaces (50%) and trees (25%) within 3 km, water (38%) and trees (35%) within 16 km, and water (47%) and trees (40%) within 80 km.

3 km
32 m
16 km
334 m
80 km
1,083 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
September weather nearby: Ban Phe 20 km · Ban Chang 23 km · Sattahip 39 km · Klaeng 44 km · Pattaya 49 km · Ban Talat Bueng 51 km · Bang Lamung 54 km · Si Racha 65 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 Rayong (12.6809°, 101.258°, elevation 7 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).