Ratchaburi weather in September

In September, Ratchaburi sees average daytime highs of 32°C and overnight lows near 26°C, with 197 mm of rain across 24.1 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 miserable.

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 Ratchaburi's 9th-clearest and 11th-windiest month. For the whole year in context, see Ratchaburi's year-round climate.

Daytime high
32°
8th warmest
Overnight low
26°
7th coldest
Rainfall
197 mm
24.1 wet days
Daylight
12 h 06 min
6:13 AM – 6:17 PM
Cloud cover
86%
9th clearest
Wind
6 km/h
11th windiest
Solar energy
4.5 kWh/m²
Travel score
2.3
out of 10

Ratchaburi is town in Ratchaburi province, Thailand.

Air quality
High
PM2.5 30 µg/m³ · 2019
Density
10,626/km²
people per km²

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 32°C through the month.

A typical September day in Ratchaburi reaches about 32°C in the afternoon and slips back to 26°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 34°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)
13326
23326
33326
43326
53326
63326
73326
83326
93326
103326
113326
123326
133326
143326
153226
163226
173226
183226
193225
203225
213225
223225
233225
243225
253225
263225
273225
283225
293225
303225

How September really feels in Ratchaburi

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
25 feel dangerously hot (≥ 39°C)
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.

Ratchaburi 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
Jan31° / 22°122.211.35.3
Feb33° / 23°102.411.54.2
Mar35° / 25°376.411.93.0
Apr36° / 27°6811.212.31.9
May35° / 27°12721.912.61.7
Jun34° / 27°11420.512.82.1
Jul33° / 26°13322.112.72.3
Aug33° / 26°14323.112.42.4
Sep32° / 26°19724.112.12.3
Oct32° / 25°18821.111.73.2
Nov31° / 24°456.411.44.6
Dec31° / 22°102.211.25.5

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 7% of September, with mostly cloudy or overcast conditions the remaining 90%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1892
2793
3793
4793
5892
6892
7892
8892
9892
10793
11892
12892
13892
14892
15892
16892
17892
181090
191090
201090
211090
221189
231288
241288
251288
261387
271387
281387
291387
301486

Chance of precipitation in September

Any precipitation

Ratchaburi gets around 197 mm of rain over 24.1 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 81% and peaks near 83% on the wettest days.

0%20%40%60%80%151015202530
Rain chance (%)
179
279
379
480
580
680
780
881
981
1081
1182
1282
1382
1482
1582
1682
1782
1882
1982
2082
2182
2282
2382
2482
2582
2682
2782
2882
2983
3083

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 63% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
15545
25446
35446
45347
55248
65248
75149
85050
94951
104852
114654
124555
134357
144159
153961
163862
173664
183466
193268
203070
212872
222773
232575
242377
252278
262179
272080
281981
291981
301882

Wind in September

Winds average 6 km/h in September.

Across September, daily wind ranges from about 5 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
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 6:12 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)
112.36:126:28
212.36:136:28
312.26:136:27
412.26:136:26
512.26:136:26
612.26:136:25
712.26:136:24
812.26:136:23
912.26:136:23
1012.26:136:22
1112.16:136:21
1212.16:136:20
1312.16:136:20
1412.16:136:19
1512.16:136:18
1612.16:136:17
1712.16:136:17
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 4.5 kWh/m².

For context, solar energy here swings from a low near 4.41 kWh/m² to a high of 6.21 kWh/m² in April across the year — September's 4.5 kWh/m² sits near the bottom.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.6Bright
44.6Bright
54.6Bright
64.6Bright
74.6Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.5Bright
174.4Bright
184.4Bright
194.4Bright
204.4Bright
214.4Bright
224.4Bright
234.4Bright
244.4Bright
254.4Bright
264.4Bright
274.4Bright
284.4Bright
294.4Bright
304.4Bright
Planning a trip in September

Hazard calendar for Ratchaburi

In seasonPeak

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

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

Ratchaburi's monsoon runs May–October, when most of the year's rain falls.

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

Is September a good time to visit Ratchaburi?

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

2.3
Sightseeing
8th-best month of the year
4.0
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Ratchaburi.

What to pack for Ratchaburi in September

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

In September, Ratchaburi sees daytime highs around 32°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 24 days see rain.

light clothesrain gearsun protection

Sea temperature near Ratchaburi in September

The nearest coast averages about 30°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 38 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
Sep30Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Ratchaburi 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 Ratchaburi peaks around August 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 20 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 15UV 13Nov 20UV 8
UV index (midday)Level
Jan8Very high
Feb9Very high
Mar12Extreme
Apr11Extreme
May11Extreme
Jun12Extreme
Jul12Extreme
Aug13Extreme
Sep12Extreme
Oct10Very high
Nov8Very high
Dec9Very high

Air quality in Ratchaburi 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 Ratchaburi is worst in February — around 44 µg/m³ PM2.5 (poor), about 2.6× the cleanest month (August, 17 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Ratchaburi's WHO annual average of 30 µg/m³.

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModerateFeb 1844 µg/m³Aug 1017 µg/m³
PM2.5 (µg/m³)Level
Jan42Poor
Feb44Poor
Mar43Poor
Apr33Moderate
May23Moderate
Jun17Moderate
Jul17Moderate
Aug17Moderate
Sep21Moderate
Oct33Moderate
Nov35Moderate
Dec34Moderate
Location & terrain

Where is Ratchaburi?

Ratchaburi sits at 13.5°N, 99.8°E, 8 m above sea level, in Thailand. The nearest listed city is Damnoen Saduak, 15 km away.

Topography around Ratchaburi

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

Within 3 km, the terrain around Ratchaburi has only modest variations in elevation — a maximum elevation change of 43 m around an average of 8 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 231 m; within 80 km, large variations in elevation — a maximum elevation change of 1,189 m.

The land around Ratchaburi is covered by artificial surfaces (47%) and trees (27%) within 3 km, trees (50%) and cropland (29%) within 16 km, and trees (44%) and cropland (25%) within 80 km.

3 km
43 m
16 km
231 m
80 km
1,189 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Damnoen Saduak 15 km · Photharam 18 km · Bang Phae 21 km · Ban I Chang 21 km · Samut Songkhram 24 km · Chom Bueng 26 km · Ban Pong 32 km · Ban Phaeo 32 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 Ratchaburi (13.5367°, 99.8171°, elevation 8 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).