Udon Thani weather in September

In September, Udon Thani sees average daytime highs of 32°C and overnight lows near 25°C, with 276 mm of rain across 24.5 wet days and about 12.1 hours of daylight. It is the 7th-warmest and 2nd-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 11% 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 Udon Thani's 9th-clearest and 12th-windiest month. For the whole year in context, see Udon Thani's year-round climate.

Daytime high
32°
7th warmest
Overnight low
25°
8th coldest
Rainfall
276 mm
24.5 wet days
Daylight
12 h 06 min
6:00 AM – 6:06 PM
Cloud cover
80%
9th clearest
Wind
5 km/h
12th windiest
Solar energy
4.45 kWh/m²
Travel score
2.7
out of 10

Udon Thani is city in Udon Thani province, Thailand.

Density
2,736/km²
people per km²
Founded
1936

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 Udon Thani 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 34°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)
13125
23125
33125
43125
53125
63125
73125
83125
93125
103125
113125
123125
133125
143225
153225
163225
173225
183225
193225
203225
213225
223225
233225
243225
253225
263225
273225
283225
293225
303225

How September really feels in Udon Thani

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
14 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.

Udon Thani weather by month

How September compares with the rest of the year at a glance. September is the 7th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 17°81.411.16.8
Feb32° / 19°142.411.45.3
Mar34° / 22°315.811.93.5
Apr35° / 25°6210.412.42.4
May34° / 26°21121.912.82.1
Jun33° / 26°22123132.3
Jul32° / 26°26625.612.92.4
Aug32° / 25°3312712.62.4
Sep32° / 25°27624.512.12.7
Oct31° / 23°9611.811.64.3
Nov30° / 21°202.911.25.9
Dec29° / 18°60.9117.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 11% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 10% of September, with mostly cloudy or overcast conditions the remaining 79%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1892
2991
3991
4991
5991
6991
71189
81189
91387
101486
111486
121585
131684
141882
151882
162179
172278
182476
192476
202773
212773
222971
233070
243169
253367
263367
273664
283763
293763
303961

Chance of precipitation in September

Any precipitation

Udon Thani gets around 276 mm of rain over 24.5 wet days in September. 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 91% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
191
291
391
491
591
691
791
890
990
1089
1188
1288
1387
1486
1584
1683
1782
1881
1979
2078
2176
2275
2373
2472
2570
2669
2767
2866
2964
3063

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 81% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
10694
20694
30694
40793
50793
60892
70892
80991
90991
1001090
1111188
1211188
1311287
1411386
1521484
1621583
1721682
1831780
1931879
2031978
2132176
2232275
2342472
2442571
2542769
2642868
2753065
2853263
2953362
3063559

Wind in September

Winds average 5 km/h in September, the calmest month.

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

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
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 5:58 AM to 6:02 AM, and sunset from 6:19 PM to 5:54 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:586:19
212.35:586:18
312.35:596:17
412.35:596:16
512.35:596:16
612.35:596:15
712.25:596:14
812.25:596:13
912.25:596:12
1012.25:596:11
1112.26:006:10
1212.26:006:10
1312.16:006:09
1412.16:006:08
1512.16:006:07
1612.16:006:06
1712.16:006:05
1812.16:016:04
1912.06:016:03
2012.06:016:03
2112.06:016:02
2212.06:016:01
2312.06:016:00
2412.06:015:59
2511.96:025:58
2611.96:025:57
2711.96:025:57
2811.96:025:56
2911.96:025:55
3011.96:025:54

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.45 kWh/m².

For context, solar energy here swings from a low near 4.27 kWh/m² to a high of 6.1 kWh/m² in April across the year — September's 4.45 kWh/m² sits near the bottom.

024151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.3Bright
44.3Bright
54.3Bright
64.3Bright
74.3Bright
84.3Bright
94.3Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.4Bright
154.4Bright
164.4Bright
174.4Bright
184.5Bright
194.5Bright
204.5Bright
214.5Bright
224.6Bright
234.6Bright
244.6Bright
254.6Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.7Bright
Planning a trip in September

Hazard calendar for Udon Thani

In seasonPeak

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

Udon Thani'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 Udon Thani?

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
9th-best month of the year

September is a weaker month for outdoor sightseeing in Udon Thani.

What to pack for Udon Thani in September

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

In September, Udon Thani 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 Udon Thani in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Udon Thani peaks around August 11 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 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 14UV 8
UV index (midday)Level
Jan8Very high
Feb10Very high
Mar12Extreme
Apr10Extreme
May12Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Extreme
Nov8Very high
Dec8Very high

Air quality in Udon Thani 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 Udon Thani is worst in March — around 65 µg/m³ PM2.5 (unhealthy), about 2.4× the cleanest month (July, 27 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecPoorUnhealthyPoorModeratePoorModerateMar 1664 µg/m³Jul 1227 µg/m³
PM2.5 (µg/m³)Level
Jan42Poor
Feb54Poor
Mar65Unhealthy
Apr52Poor
May36Poor
Jun28Moderate
Jul27Moderate
Aug29Moderate
Sep34Moderate
Oct37Poor
Nov35Poor
Dec34Moderate
Location & terrain

Where is Udon Thani?

Udon Thani sits at 17.4°N, 102.8°E, 177 m above sea level, in Thailand. The nearest listed city is Kut Chap, 23 km away.

Topography around Udon Thani

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

Within 3 km, the terrain around Udon Thani has only modest variations in elevation — a maximum elevation change of 19 m around an average of 177 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 70 m; within 80 km, significant variations in elevation — a maximum elevation change of 511 m.

The land around Udon Thani is covered by artificial surfaces (58%) and trees (32%) within 3 km, cropland (48%) and trees (35%) within 16 km, and cropland (62%) and trees (32%) within 80 km.

3 km
19 m
16 km
70 m
80 km
511 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Kut Chap 23 km · Ban Phan Don 36 km · Nong Bua Lamphu 44 km · Ban Nong Wua So 49 km · Nong Khai 52 km · Tha Bo 53 km · Ban Dung 59 km · Vientiane 64 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 Udon Thani (17.4157°, 102.7859°, elevation 177 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).