Chũ weather in September

In September, Chũ sees average daytime highs of 31°C and overnight lows near 24°C, with 233 mm of rain across 20.1 wet days and about 12.1 hours of daylight. It is the 4th-warmest and 5th-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 20% of the time in September, and the air most often feels miserable.

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 Chũ's 4th-clearest and 11th-windiest month. For the whole year in context, see Chũ's year-round climate.

Daytime high
31°
4th warmest
Overnight low
24°
8th coldest
Rainfall
233 mm
20.1 wet days
Daylight
12 h 06 min
5:44 AM – 5:52 PM
Cloud cover
70%
4th clearest
Wind
7 km/h
11th windiest
Solar energy
4.44 kWh/m²
Travel score
3.4
out of 10

Chũ is ward in Bắc Ninh province, Vietnam.

Density
40,088/km²
people per km²
Founded
1957

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 31°C through the month.

A typical September day in Chũ 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 28°C and 33°C. Set against its neighbours, September runs about 1°C cooler than August and about 2°C warmer than 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
143125
153124
163124
173124
183124
193124
203124
213124
223124
233124
243124
253124
263024
273024
283023
293023
303023

How September really feels in Chũ

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
2 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.

Chũ weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan19° / 14°376.810.86.2
Feb21° / 15°226.311.36.4
Mar23° / 18°491011.86.4
Apr28° / 22°7911.912.55.5
May31° / 24°25420.2133.4
Jun32° / 26°2872213.32.5
Jul32° / 26°30124.613.22.5
Aug32° / 26°36626.212.72.5
Sep31° / 24°23320.112.13.4
Oct29° / 22°10211.911.55.5
Nov25° / 18°557.7117.0
Dec21° / 15°346.510.76.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 20% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 66%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12377
22377
32476
42476
52476
62476
72476
82674
92773
102773
112872
123070
133169
143169
153367
163466
173664
183664
193862
203961
214060
224159
234258
244357
254456
264456
274555
284654
294753
304753

Chance of precipitation in September

Any precipitation

Chũ gets around 233 mm of rain over 20.1 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 67% and peaks near 81% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
181
281
381
480
580
679
778
877
976
1075
1174
1273
1371
1470
1568
1666
1765
1863
1962
2060
2159
2257
2356
2455
2554
2653
2752
2851
2950
3049

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 64% of days. Sticky, muggy-or-worse air turns up on roughly 97% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10011188
20011287
30011386
40121384
50121483
60131581
70131581
80141679
90141778
100251776
110261874
120261874
130271972
140282070
150292069
1603102166
1703112264
1803122362
1903132559
2003132658
2104142755
2204152952
2304163050
2404163148
2505173345
2605183443
2706183540
2807183738
2917193835
3018193833

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 6 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
16calm
26calm
36calm
46calm
56calm
66calm
76calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
288calm
298calm
308calm

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 5:41 AM to 5:48 AM, and sunset from 6:06 PM to 5:38 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:416:06
212.45:416:05
312.45:416:04
412.45:416:04
512.35:426:03
612.35:426:02
712.35:426:01
812.35:426:00
912.35:435:59
1012.25:435:58
1112.25:435:57
1212.25:435:56
1312.25:445:55
1412.25:445:54
1512.15:445:53
1612.15:445:52
1712.15:455:51
1812.15:455:50
1912.15:455:49
2012.05:455:48
2112.05:465:47
2212.05:465:46
2312.05:465:45
2412.05:475:44
2511.95:475:43
2611.95:475:42
2711.95:475:41
2811.95:485:40
2911.85:485:39
3011.85:485:38

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.44 kWh/m².

For context, solar energy here swings from a low near 2.25 kWh/m² to a high of 4.86 kWh/m² in June across the year — September's 4.44 kWh/m² falls in the middle.

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
144.5Bright
154.5Bright
164.5Bright
174.5Bright
184.5Bright
194.5Bright
204.5Bright
214.5Bright
224.5Bright
234.5Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
Planning a trip in September

Hazard calendar for Chũ

In seasonPeak

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

Chũ'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 Chũ?

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

3.4
Sightseeing
8th-best month of the year
5.0
Beach & pool
6th-best month of the year

September is a weaker month for outdoor sightseeing in Chũ.

What to pack for Chũ in September

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

In September, Chũ sees daytime highs around 31°C and nights near 24°C. Pack light clothes and rain gear. About 20 days see rain.

light clothesrain gear

UV index in Chũ in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Chũ peaks around June 21 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJun 21UV 11Dec 15UV 6
UV index (midday)Level
Jan7High
Feb7Very high
Mar8Very high
Apr7High
May9Very high
Jun12Extreme
Jul11Extreme
Aug8Very high
Sep8Very high
Oct8Very high
Nov6High
Dec6High

Air quality in Chũ 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 Chũ is worst in December — around 92 µg/m³ PM2.5 (unhealthy), about 2.6× the cleanest month (July, 35 µg/m³).

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

0306090120JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyPoorUnhealthyDec 2192 µg/m³Jul 1335 µg/m³
PM2.5 (µg/m³)Level
Jan90Unhealthy
Feb80Unhealthy
Mar76Unhealthy
Apr66Unhealthy
May49Poor
Jun37Poor
Jul35Moderate
Aug40Poor
Sep59Unhealthy
Oct74Unhealthy
Nov82Unhealthy
Dec92Unhealthy
Location & terrain

Where is Chũ?

Chũ sits at 21.4°N, 106.6°E, 18 m above sea level, in Vietnam. The nearest listed city is Thị Trấn Đông Triều, 33 km away.

Topography around Chũ

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

Within 3 km, the terrain around Chũ has only modest variations in elevation — a maximum elevation change of 202 m around an average of 17 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 508 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,567 m.

The land around Chũ is covered by trees (84%) within 3 km, trees (87%) within 16 km, and trees (67%) within 80 km.

3 km
202 m
16 km
508 m
80 km
1,567 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Thị Trấn Đông Triều 33 km · Thị Trấn Mạo Khê 35 km · Bắc Giang 40 km · Chí Linh 43 km · Thành Phố Uông Bí 43 km · Việt Yên 46 km · Cung Kiệm 47 km · Hải Dương 54 km

Vietnam travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C / F
220 V · 50 Hz
Prices
≈ 29% of US
price level, 2025
GDP per capita
$5,066
2025
Happiness
6.4 / 10
World Happiness, 2025
Safe drinking water
59%
of population, 2024
Homicide rate
1.5
per 100k, 2011
Road deaths
30.6
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 500
Religion
none 86%Catholic 6%Buddhist 6%Protestant 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 Chũ (21.3738°, 106.5665°, elevation 18 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).