Roi Et weather in September

In September, Roi Et sees average daytime highs of 32°C and overnight lows near 25°C, with 253 mm of rain across 24.5 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 7% 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 Roi Et's 9th-clearest and 12th-windiest month. For the whole year in context, see Roi Et's year-round climate.

Daytime high
32°
8th warmest
Overnight low
25°
7th coldest
Rainfall
253 mm
24.5 wet days
Daylight
12 h 06 min
5:57 AM – 6:02 PM
Cloud cover
83%
9th clearest
Wind
7 km/h
12th windiest
Solar energy
4.47 kWh/m²
Travel score
2.7
out of 10

Roi Et is town in Roi Et province, Thailand.

Density
3,382/km²
people per km²
Founded
1937

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 Roi Et reaches about 32°C in the afternoon and slips back to 25°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 33°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)
13225
23225
33225
43225
53225
63225
73225
83225
93225
103125
113125
123125
133125
143125
153125
163125
173125
183125
193125
203125
213125
223125
233125
243225
253225
263225
273225
283225
293225
303225

How September really feels in Roi Et

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
9 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.

Roi Et 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° / 18°61.611.25.9
Feb33° / 20°112.111.54.6
Mar35° / 24°376.511.92.9
Apr36° / 26°6611.312.42.1
May34° / 26°18021.312.72.0
Jun33° / 26°16921.212.92.2
Jul33° / 26°20723.512.92.4
Aug32° / 25°24025.212.52.5
Sep32° / 25°25324.512.12.7
Oct31° / 24°10912.511.64.0
Nov31° / 22°243.511.35.2
Dec30° / 19°51.211.16.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 7% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 9% of September, with mostly cloudy or overcast conditions the remaining 84%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1793
2793
3793
4793
5793
6793
7892
81090
91189
101189
111189
121387
131387
141486
151585
161684
171783
181882
192080
202080
212179
222179
232278
242377
252476
262575
272575
282674
292773
302872

Chance of precipitation in September

Any precipitation

Roi Et gets around 253 mm of rain over 24.5 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 88% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
187
287
387
488
588
688
788
888
987
1087
1187
1286
1386
1485
1584
1683
1782
1881
1980
2079
2178
2276
2375
2474
2573
2672
2770
2869
2968
3067

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 76% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
101387
201387
301387
401387
501387
601387
701486
801486
911584
1011584
1111683
1211782
1311881
1411980
1511980
1612178
1722276
1822375
1922474
2022573
2122672
2222870
2322969
2423167
2523365
2633463
2733661
2833859
2944056
3044155

Wind in September

Winds average 7 km/h in September, the calmest month.

Across September, daily wind ranges from about 7 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

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 5:56 AM to 5:59 AM, and sunset from 6:15 PM to 5:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:566:15
212.35:566:14
312.35:566:13
412.35:566:12
512.35:566:11
612.25:566:11
712.25:566:10
812.25:566:09
912.25:566:08
1012.25:576:07
1112.25:576:07
1212.25:576:06
1312.15:576:05
1412.15:576:04
1512.15:576:03
1612.15:576:02
1712.15:576:02
1812.15:576:01
1912.05:576:00
2012.05:575:59
2112.05:585:58
2212.05:585:57
2312.05:585:57
2412.05:585:56
2511.95:585:55
2611.95:585:54
2711.95:585:53
2811.95:585:52
2911.95:585:52
3011.95:595:51

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.47 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.47 kWh/m² to a high of 6.16 kWh/m² in April across the year — September's 4.47 kWh/m² sits near the bottom.

024151015202530
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
124.4Bright
134.4Bright
144.4Bright
154.4Bright
164.4Bright
174.4Bright
184.4Bright
194.5Bright
204.5Bright
214.5Bright
224.5Bright
234.5Bright
244.5Bright
254.6Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.6Bright
Planning a trip in September

Hazard calendar for Roi Et

In seasonPeak

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

Roi Et's monsoon runs May–September, when most of the year's rain falls.

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

Is September a good time to visit Roi Et?

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

2.7
Sightseeing
7th-best month of the year
4.2
Beach & pool
10th-best month of the year

September is a weaker month for outdoor sightseeing in Roi Et.

What to pack for Roi Et in September

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

In September, Roi Et 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

UV index in Roi Et 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 Roi Et peaks around August 11 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 10 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 11UV 13Dec 10UV 8
UV index (midday)Level
Jan9Very high
Feb11Extreme
Mar12Extreme
Apr10Very high
May11Extreme
Jun12Extreme
Jul13Extreme
Aug13Extreme
Sep12Extreme
Oct11Extreme
Nov8Very high
Dec8Very high

Air quality in Roi Et 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 Roi Et is worst in March — around 52 µg/m³ PM2.5 (poor), about 2.6× the cleanest month (December, 20 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateMar 1751 µg/m³Dec 1320 µg/m³
PM2.5 (µg/m³)Level
Jan28Moderate
Feb40Poor
Mar52Poor
Apr41Poor
May30Moderate
Jun22Moderate
Jul24Moderate
Aug25Moderate
Sep28Moderate
Oct28Moderate
Nov23Moderate
Dec20Moderate
Location & terrain

Where is Roi Et?

Roi Et sits at 16.1°N, 103.7°E, 148 m above sea level, in Thailand. The nearest listed city is Ban Selaphum, 32 km away.

Topography around Roi Et

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

Within 3 km, the terrain around Roi Et has only modest variations in elevation — a maximum elevation change of 30 m around an average of 147 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 61 m; within 80 km, significant variations in elevation — a maximum elevation change of 385 m.

The land around Roi Et is covered by artificial surfaces (41%) and trees (34%) within 3 km, cropland (76%) within 16 km, and cropland (79%) within 80 km.

3 km
30 m
16 km
61 m
80 km
385 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Ban Selaphum 32 km · Kamalasai 32 km · Maha Sarakham 40 km · Kalasin 45 km · Kaset Wisai 45 km · Yasothon 60 km · Kuchinarai 69 km · Nong Kung Si 76 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 Roi Et (16.0567°, 103.6531°, elevation 148 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. 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).