Phayao weather in September

In September, Phayao sees average daytime highs of 32°C and overnight lows near 24°C, with 208 mm of rain across 23 wet days and about 12.1 hours of daylight. It is the 7th-warmest and 3rd-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 oppressive.

Daylight stretches from about 12 h 24 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Phayao's 9th-clearest and 9th-windiest month. For the whole year in context, see Phayao's year-round climate.

Daytime high
32°
7th warmest
Overnight low
24°
8th coldest
Rainfall
208 mm
23 wet days
Daylight
12 h 06 min
6:12 AM – 6:18 PM
Cloud cover
82%
9th clearest
Wind
5 km/h
9th windiest
Solar energy
4.33 kWh/m²
Travel score
2.8
out of 10

Phayao is town in Phayao province, Thailand.

Air quality
Elevated
PM2.5 18 µg/m³ · 2019
Founded
1938

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 Phayao reaches about 32°C in the afternoon and slips back to 24°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)
13225
23225
33225
43225
53224
63224
73124
83124
93124
103124
113224
123224
133224
143224
153224
163224
173224
183224
193224
203224
213224
223224
233224
243224
253224
263224
273224
283224
293224
303124

How September really feels in Phayao

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.

Phayao weather by month

How September compares with the rest of the year at a glance. September is the 7th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 16°152.5116.8
Feb32° / 17°61.211.35.2
Mar35° / 20°283.911.93.4
Apr35° / 24°719.512.42.4
May34° / 25°16619.712.92.4
Jun33° / 25°14421.513.12.4
Jul32° / 25°22124.8132.5
Aug31° / 25°25326.412.72.6
Sep32° / 24°2082312.12.8
Oct31° / 23°9814.711.64.1
Nov30° / 20°31511.16.0
Dec28° / 17°162.410.97.6

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 10% of September, with mostly cloudy or overcast conditions the remaining 83%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1793
2793
3892
4892
5991
6991
71090
81189
91189
101189
111288
121288
131387
141387
151585
161585
171684
181783
191882
202080
212080
222278
232377
242476
252674
262773
272971
283169
293268
303367

Chance of precipitation in September

Any precipitation

Phayao gets around 208 mm of rain over 23 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 76% 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
283
383
483
583
682
782
882
981
1081
1180
1279
1379
1478
1577
1677
1776
1875
1974
2074
2173
2272
2372
2471
2570
2669
2769
2868
2967
3066

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 70% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
106337
206337
306337
406337
506337
606337
706337
806337
906436
1006436
1106535
1216534
1316633
1416732
1516831
1616930
1717029
1817128
1917227
2027226
2127325
2227424
2327523
2427622
2527820
2637819
2737918
2838017
2938116
3038215

Wind in September

Winds average 5 km/h in September.

Across September, daily wind ranges from about 4 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
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 24 min at the start of September to 11 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 36 minutes over September. Sunrise moves from 6:09 AM to 6:14 AM, and sunset from 6:32 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.46:096:32
212.46:096:31
312.36:096:30
412.36:096:29
512.36:106:28
612.36:106:27
712.36:106:26
812.36:106:25
912.26:106:25
1012.26:106:24
1112.26:116:23
1212.26:116:22
1312.26:116:21
1412.16:116:20
1512.16:116:19
1612.16:126:18
1712.16:126:17
1812.16:126:16
1912.16:126:15
2012.06:126:14
2112.06:136:13
2212.06:136:12
2312.06:136:12
2412.06:136:11
2511.96:136:10
2611.96:146:09
2711.96:146:08
2811.96:146:07
2911.96:146:06
3011.86:146:05

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.33 kWh/m².

For context, solar energy here swings from a low near 4.08 kWh/m² to a high of 6.36 kWh/m² in April across the year — September's 4.33 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.2Bright
44.2Bright
54.2Bright
64.2Bright
74.2Bright
84.2Bright
94.2Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.3Bright
174.3Bright
184.3Bright
194.3Bright
204.3Bright
214.4Bright
224.4Bright
234.4Bright
244.4Bright
254.4Bright
264.4Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
Planning a trip in September

Hazard calendar for Phayao

In seasonPeak

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

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

Phayao's monsoon runs May–September, 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 Phayao?

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

2.8
Sightseeing
7th-best month of the year
4.3
Beach & pool
9th-best month of the year

September is a weaker month for outdoor sightseeing in Phayao.

What to pack for Phayao in September

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

In September, Phayao sees daytime highs around 32°C and nights near 24°C. Pack light clothes and rain gear. About 23 days see rain.

light clothesrain gear

UV index in Phayao 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 Phayao peaks around August 12 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 at about 7 (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 18UV 7
UV index (midday)Level
Jan8Very high
Feb9Very high
Mar9Very high
Apr10Very high
May11Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Phayao 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 Phayao is worst in March — around 51 µg/m³ PM2.5 (poor), about 5.9× the cleanest month (July, 9 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Phayao's WHO annual average of 18 µg/m³.

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateGoodModerateMar 2049 µg/m³Jul 199 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb23Moderate
Mar51Poor
Apr39Poor
May16Moderate
Jun9Good
Jul9Good
Aug9Good
Sep9Good
Oct10Good
Nov11Good
Dec13Moderate
Location & terrain

Where is Phayao?

Phayao sits at 19.2°N, 99.9°E, 409 m above sea level, in Thailand. The nearest listed city is Dok Kham Tai, 12 km away.

San KamphaengChiang MaiNanMae ChanLampangLamphun

Topography around Phayao

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

Within 3 km, the terrain around Phayao has only modest variations in elevation — a maximum elevation change of 61 m around an average of 402 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,289 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,796 m.

The land around Phayao is covered by trees (33%) and water (30%) within 3 km, cropland (45%) and trees (44%) within 16 km, and trees (77%) within 80 km.

3 km
61 m
16 km
1,289 m
80 km
1,796 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Dok Kham Tai 12 km · Chiang Rai 80 km · San Kamphaeng 94 km · Chiang Mai 104 km · Nan 105 km · Mae Chan 106 km · Lampang 108 km · Lamphun 114 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 Phayao (19.192°, 99.8788°, elevation 409 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). 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).