Ban Na San weather in September

In September, Ban Na San sees average daytime highs of 31°C and overnight lows near 24°C, with 235 mm of rain across 26.1 wet days and about 12.1 hours of daylight. It is the 9th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 1% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Ban Na San's 12th-clearest and 6th-windiest month. For the whole year in context, see Ban Na San's year-round climate.

Daytime high
31°
9th warmest
Overnight low
24°
7th coldest
Rainfall
235 mm
26.1 wet days
Daylight
12 hours
6:15 AM – 6:18 PM
Cloud cover
88%
12th clearest
Wind
6 km/h
6th windiest
Solar energy
4.7 kWh/m²
Travel score
2.6
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical September day in Ban Na San reaches about 31°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 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)
13124
23124
33124
43124
53124
63124
73124
83124
93124
103124
113124
123124
133124
143124
153124
163124
173124
183124
193124
203124
213124
223124
233124
243124
253124
263124
273124
283124
293124
303124

How September really feels in Ban Na San

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.

Ban Na San weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan32° / 22°678.411.54.3
Feb34° / 23°37511.73.5
Mar35° / 24°11011.211.92.5
Apr35° / 25°16118.712.22.0
May33° / 25°18924.812.42.2
Jun32° / 24°16022.612.52.7
Jul31° / 24°16623.612.52.8
Aug31° / 24°19324.112.32.8
Sep31° / 24°23526.112.12.6
Oct31° / 24°33328.611.82.6
Nov30° / 23°26823.111.63.1
Dec30° / 23°13915.211.54.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 6% of September, with mostly cloudy or overcast conditions the remaining 93%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1892
2892
3892
4793
5793
6793
7793
8793
9793
10793
11793
12793
13793
14892
15892
16892
17892
18892
19892
20793
21793
22793
23793
24793
25694
26694
27595
28595
29595
30595

Chance of precipitation in September

Any precipitation

Ban Na San gets around 235 mm of rain over 26.1 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 88% and peaks near 93% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
185
285
384
484
584
684
785
885
985
1086
1186
1286
1387
1487
1587
1687
1788
1888
1989
2089
2190
2290
2390
2491
2591
2691
2792
2892
2992
3093

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 57% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
15644
25644
35644
45644
55644
65743
75743
85842
95842
105941
115941
125941
135941
145941
155941
165941
175842
185842
195743
205743
215644
225644
235545
245545
255446
265446
275347
285347
295347
305347

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 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 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 18 minutes over September. Sunrise moves from 6:17 AM to 6:14 AM, and sunset from 6:27 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:176:27
212.26:176:27
312.26:176:26
412.16:176:26
512.16:176:25
612.16:176:24
712.16:176:24
812.16:166:23
912.16:166:23
1012.16:166:22
1112.16:166:21
1212.16:166:21
1312.16:166:20
1412.16:166:20
1512.16:166:19
1612.06:156:18
1712.06:156:18
1812.06:156:17
1912.06:156:16
2012.06:156:16
2112.06:156:15
2212.06:156:15
2312.06:156:14
2412.06:146:13
2512.06:146:13
2612.06:146:12
2712.06:146:12
2811.96:146:11
2911.96:146:10
3011.96:146:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.7 kWh/m².

For context, solar energy here swings from a low near 4.01 kWh/m² to a high of 6.05 kWh/m² in March across the year — September's 4.7 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.8Bright
54.8Bright
64.8Bright
74.8Bright
84.8Bright
94.8Bright
104.7Bright
114.7Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.7Bright
174.6Bright
184.6Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
Planning a trip in September

Hazard calendar for Ban Na San

In seasonPeak

In September, Ban Na San sits inside its cyclone season. The full year is below, with each hazard's peak months called out.

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

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

Is September a good time to visit Ban Na San?

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

2.6
Sightseeing
8th-best month of the year
3.8
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Ban Na San.

What to pack for Ban Na San in September

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

In September, Ban Na San sees daytime highs around 31°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 26 days see rain.

light clothesrain gearsun protection

Sea temperature near Ban Na San in September

The nearest coast averages about 29°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 64 km away) is warmest in May at about 31°C and coldest in January near 28°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
Jan28Warm
Feb28Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul30Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Ban Na San in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ban Na San peaks around August 22 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 10 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeAug 22UV 13Dec 15UV 10
UV index (midday)Level
Jan11Extreme
Feb13Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun12Extreme
Jul11Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov10Extreme
Dec10Very high

Air quality in Ban Na San 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 Ban Na San is worst in April — around 21 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1021 µg/m³Aug 2014 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb18Moderate
Mar20Moderate
Apr21Moderate
May17Moderate
Jun16Moderate
Jul16Moderate
Aug14Moderate
Sep15Moderate
Oct15Moderate
Nov14Moderate
Dec15Moderate
Location & terrain

Where is Ban Na San?

Ban Na San sits at 8.8°N, 99.4°E, 40 m above sea level, in Thailand. The nearest listed city is Tha Kham, 37 km away.

KrabiKo SamuiAo Nang

Topography around Ban Na San

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

Within 3 km, the terrain around Ban Na San has significant variations in elevation — a maximum elevation change of 257 m around an average of 55 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,544 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,784 m.

The land around Ban Na San is covered by trees (85%) within 3 km, trees (89%) within 16 km, and trees (82%) within 80 km.

3 km
257 m
16 km
1,544 m
80 km
1,784 m
treesgrasslandcroplandartificial surfaceswatermangroves
September weather nearby: Tha Kham 37 km · Surat Thani 38 km · Nakhon Si Thammarat 78 km · Thung Song 79 km · Ron Phibun 88 km · Krabi 95 km · Ko Samui 103 km · Ao Nang 104 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 Ban Na San (8.8004°, 99.3637°, elevation 40 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).