Nam Định weather in September

In September, Nam Định sees average daytime highs of 31°C and overnight lows near 25°C, with 277 mm of rain across 20.6 wet days and about 12.1 hours of daylight. It is the 5th-warmest and 2nd-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 19% 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 Nam Định's 5th-clearest and 12th-windiest month. For the whole year in context, see Nam Định's year-round climate.

Daytime high
31°
5th warmest
Overnight low
25°
8th coldest
Rainfall
277 mm
20.6 wet days
Daylight
12 h 06 min
5:46 AM – 5:53 PM
Cloud cover
72%
5th clearest
Wind
8 km/h
12th windiest
Solar energy
4.4 kWh/m²
Travel score
3.3
out of 10

Nam Định is the former provincial capital of the former Nam Dinh province, Vietnam.

Density
9,660/km²
people per km²
Founded
1921

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 Nam Định reaches about 31°C in the afternoon and slips back to 25°C overnight — a 6°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)
13226
23226
33226
43126
53126
63126
73126
83126
93126
103126
113126
123126
133126
143126
153125
163125
173125
183125
193125
203125
213125
223125
233125
243125
253125
263125
273125
283025
293025
303024

How September really feels in Nam Định

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
7 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.

Nam Định weather by month

How September compares with the rest of the year at a glance. September is the 5th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan20° / 15°285.510.96.6
Feb22° / 17°154.111.36.9
Mar24° / 19°366.411.97.0
Apr28° / 23°638.712.56.0
May31° / 26°19616.3133.6
Jun33° / 28°18916.413.22.6
Jul33° / 28°24618.413.12.6
Aug32° / 27°34223.612.72.6
Sep31° / 25°27720.612.13.3
Oct29° / 23°14213.611.55.1
Nov26° / 20°618.3116.9
Dec22° / 16°296.310.87.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% 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 67%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12080
22080
32080
42080
52179
62179
72377
82476
92476
102674
112773
122971
132971
143169
153367
163466
173565
183763
193862
203961
214060
224258
234357
244456
254456
264456
274555
284555
294555
304753

Chance of precipitation in September

Any precipitation

Nam Định gets around 277 mm of rain over 20.6 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 68% and peaks near 83% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
183
283
383
483
582
681
780
879
978
1076
1175
1273
1372
1470
1568
1666
1765
1863
1962
2061
2160
2259
2358
2457
2557
2656
2756
2856
2955
3055

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 76% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202530
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
100397
200496
300595
401594
511692
611791
711791
812889
912988
10121087
11121186
12131284
13131482
14141580
15141679
16151876
17151975
18162073
19162271
20172369
21172567
22282664
23292762
24292960
252103058
262113156
273113155
283123253
294133350
304143349

Wind in September

Winds average 8 km/h in September, the calmest month.

Across September, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

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 5:43 AM to 5:50 AM, and sunset from 6:07 PM to 5:40 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:436:07
212.45:436:06
312.45:436:05
412.45:436:05
512.35:446:04
612.35:446:03
712.35:446:02
812.35:446:01
912.35:456:00
1012.25:455:59
1112.25:455:58
1212.25:455:57
1312.25:455:56
1412.25:465:55
1512.15:465:54
1612.15:465:53
1712.15:465:52
1812.15:475:51
1912.15:475:50
2012.05:475:49
2112.05:475:48
2212.05:485:47
2312.05:485:46
2412.05:485:45
2511.95:485:44
2611.95:495:43
2711.95:495:42
2811.95:495:42
2911.95:495:41
3011.85:505:40

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.4 kWh/m².

For context, solar energy here swings from a low near 2.42 kWh/m² to a high of 5.27 kWh/m² in June across the year — September's 4.4 kWh/m² falls in the middle.

012345151015202530
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
144.4Bright
154.4Bright
164.4Bright
174.4Bright
184.4Bright
194.5Bright
204.5Bright
214.5Bright
224.5Bright
234.5Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.4Bright
294.4Bright
304.4Bright
Planning a trip in September

Hazard calendar for Nam Định

In seasonPeak

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

Nam Định sits in the Pacific typhoon belt; the season peaks July–October.

Nam Định's monsoon runs May–September, when most of the year's rain falls.

Pacific typhoon
Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Nam Định?

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

3.3
Sightseeing
9th-best month of the year
4.9
Beach & pool
7th-best month of the year

September is a weaker month for outdoor sightseeing in Nam Định.

What to pack for Nam Định in September

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

In September, Nam Định sees daytime highs around 31°C and nights near 25°C. Pack light clothes and rain gear. About 21 days see rain.

light clothesrain gear

Sea temperature near Nam Định 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 40 km away) is warmest in August at about 30°C and coldest in February near 20°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb20Refreshing
Mar21Refreshing
Apr24Refreshing
May27Warm
Jun29Tropical
Jul30Tropical
Aug30Tropical
Sep29Tropical
Oct28Tropical
Nov26Warm
Dec23Refreshing

UV index in Nam Định 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 Nam Định peaks around July 12 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highVery highExtremeVery highHighJul 12UV 11Dec 16UV 6
UV index (midday)Level
Jan7High
Feb8Very high
Mar9Very high
Apr7High
May9Very high
Jun11Extreme
Jul11Extreme
Aug10Very high
Sep8Very high
Oct8Very high
Nov7High
Dec6High

Air quality in Nam Định 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 Nam Định is worst in January — around 67 µg/m³ PM2.5 (unhealthy), about 2.7× the cleanest month (July, 25 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyPoorModeratePoorUnhealthyJan 1166 µg/m³Jul 1525 µg/m³
PM2.5 (µg/m³)Level
Jan67Unhealthy
Feb61Unhealthy
Mar61Unhealthy
Apr51Poor
May37Poor
Jun27Moderate
Jul25Moderate
Aug27Moderate
Sep41Poor
Oct52Poor
Nov56Unhealthy
Dec66Unhealthy
Location & terrain

Where is Nam Định?

Nam Định sits at 20.4°N, 106.2°E, 5 m above sea level, in Vietnam. The nearest listed city is Thái Bình, 17 km away.

Topography around Nam Định

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

Within 3 km, the terrain around Nam Định has only modest variations in elevation — a maximum elevation change of 14 m around an average of 5 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 63 m; within 80 km, large variations in elevation — a maximum elevation change of 1,061 m.

The land around Nam Định is covered by artificial surfaces (53%) within 3 km, cropland (59%) within 16 km, and cropland (36%), water (28%) and trees (23%) within 80 km.

3 km
14 m
16 km
63 m
80 km
1,061 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
September weather nearby: Thái Bình 17 km · Hưng Yên 27 km · Ninh Binh 28 km · Phủ Lý 30 km · Lương Bằng 36 km · Bỉm Sơn 52 km · Nga Sơn 52 km · Mỹ Hào 55 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 Nam Định (20.4339°, 106.1773°, elevation 5 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).