Khon Kaen weather in September

In September, Khon Kaen sees average daytime highs of 32°C and overnight lows near 25°C, with 237 mm of rain across 23.3 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 8% 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 Khon Kaen's 9th-clearest and 12th-windiest month. For the whole year in context, see Khon Kaen's year-round climate.

Daytime high
32°
8th warmest
Overnight low
25°
7th coldest
Rainfall
237 mm
23.3 wet days
Daylight
12 h 06 min
6:00 AM – 6:06 PM
Cloud cover
81%
9th clearest
Wind
6 km/h
12th windiest
Solar energy
4.58 kWh/m²
Travel score
2.7
out of 10

Khon Kaen is city in Khon Kaen province, Thailand.

Air quality
High
PM2.5 34 µg/m³ · 2019
Density
2,488/km²
people per km²
Founded
1935

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 Khon Kaen 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 30°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)
13225
23225
33225
43225
53225
63225
73225
83225
93225
103225
113225
123225
133225
143225
153225
163225
173225
183225
193225
203225
213225
223225
233225
243225
253225
263225
273225
283225
293225
303225

How September really feels in Khon Kaen

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
16 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.

Khon Kaen 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° / 18°71.611.16.0
Feb33° / 20°112.411.44.5
Mar35° / 24°345.911.92.8
Apr36° / 26°6510.712.42.0
May35° / 26°15220.112.82.0
Jun34° / 26°13419.2132.2
Jul33° / 26°16420.312.92.4
Aug32° / 26°21423.312.62.5
Sep32° / 25°23723.312.12.7
Oct31° / 24°10412.811.64.1
Nov31° / 21°243.511.25.4
Dec30° / 19°51116.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 8% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 11% of September, with mostly cloudy or overcast conditions the remaining 81%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1694
2694
3793
4892
5892
6892
71090
81090
91189
101288
111387
121387
131585
141684
151981
161981
172179
182278
192377
202476
212674
222773
232773
242872
252971
263070
273070
283367
293367
303466

Chance of precipitation in September

Any precipitation

Khon Kaen gets around 237 mm of rain over 23.3 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 78% and peaks near 84% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
184
284
384
484
584
684
784
883
983
1083
1182
1282
1381
1481
1580
1679
1778
1877
1976
2075
2174
2273
2372
2471
2571
2670
2769
2868
2967
3066

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 77% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
101783
201783
301783
401783
501783
601783
701783
801783
901783
1001783
1111782
1211782
1311782
1411881
1511881
1611980
1712079
1822078
1922177
2022276
2122375
2222474
2322672
2422771
2522969
2633067
2733265
2833463
2933562
3043759

Wind in September

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

Across September, daily wind ranges from about 6 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
37calm
47calm
57calm
67calm
77calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

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 5:59 AM to 6:02 AM, and sunset from 6:18 PM to 5:54 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:596:18
212.35:596:17
312.35:596:17
412.35:596:16
512.35:596:15
612.25:596:14
712.25:596:13
812.25:596:12
912.26:006:12
1012.26:006:11
1112.26:006:10
1212.26:006:09
1312.16:006:08
1412.16:006:07
1512.16:006:07
1612.16:006:06
1712.16:006:05
1812.16:006:04
1912.06:016:03
2012.06:016:02
2112.06:016:01
2212.06:016:01
2312.06:016:00
2412.06:015:59
2511.96:015:58
2611.96:015:57
2711.96:015:56
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 4.58 kWh/m².

For context, solar energy here swings from a low near 4.52 kWh/m² to a high of 6.1 kWh/m² in April across the year — September's 4.58 kWh/m² sits near the bottom.

024151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.5Bright
174.5Bright
184.5Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.7Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.7Bright
Planning a trip in September

Hazard calendar for Khon Kaen

In seasonPeak

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

Khon Kaen'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 Khon Kaen?

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
4.3
Beach & pool
10th-best month of the year

September is a weaker month for outdoor sightseeing in Khon Kaen.

What to pack for Khon Kaen in September

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

In September, Khon Kaen sees daytime highs around 32°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 23 days see rain.

light clothesrain gearsun protection

UV index in Khon Kaen 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 Khon Kaen peaks around August 12 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 12UV 13Dec 14UV 8
UV index (midday)Level
Jan9Very high
Feb10Extreme
Mar12Extreme
Apr10Very high
May12Extreme
Jun12Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Extreme
Nov8Very high
Dec8Very high

Air quality in Khon Kaen 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 Khon Kaen is worst in March — around 56 µg/m³ PM2.5 (unhealthy), about 2.5× the cleanest month (June, 22 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Khon Kaen's WHO annual average of 34 µg/m³.

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorPoorModerateMar 1555 µg/m³Jun 2222 µg/m³
PM2.5 (µg/m³)Level
Jan37Poor
Feb48Poor
Mar56Unhealthy
Apr43Poor
May31Moderate
Jun22Moderate
Jul23Moderate
Aug24Moderate
Sep29Moderate
Oct33Moderate
Nov31Moderate
Dec29Moderate
Location & terrain

Where is Khon Kaen?

Khon Kaen sits at 16.4°N, 102.8°E, 167 m above sea level, in Thailand. The nearest listed city is Ban Phai, 44 km away.

Topography around Khon Kaen

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

Within 3 km, the terrain around Khon Kaen has only modest variations in elevation — a maximum elevation change of 64 m around an average of 165 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 80 m; within 80 km, large variations in elevation — a maximum elevation change of 683 m.

The land around Khon Kaen is covered by artificial surfaces (51%) and trees (35%) within 3 km, cropland (54%) and trees (26%) within 16 km, and cropland (75%) within 80 km.

3 km
64 m
16 km
80 m
80 km
683 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Ban Phai 44 km · Nong Kung Si 55 km · Maha Sarakham 58 km · Kalasin 72 km · Kaeng Khro 72 km · Phu Khiao 76 km · Ban Phan Don 79 km · Chum Phae 79 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 Khon Kaen (16.4467°, 102.833°, elevation 167 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).