Rājbirāj weather in September

In September, Rājbirāj sees average daytime highs of 32°C and overnight lows near 26°C, with 308 mm of rain across 23.8 wet days and about 12.2 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 22% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 36 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Rājbirāj's 9th-clearest and 7th-windiest month. For the whole year in context, see Rājbirāj's year-round climate.

Daytime high
32°
7th warmest
Overnight low
26°
9th coldest
Rainfall
308 mm
23.8 wet days
Daylight
12 h 12 min
5:48 AM – 5:57 PM
Cloud cover
68%
9th clearest
Wind
9 km/h
7th windiest
Solar energy
3.95 kWh/m²
Travel score
2.8
out of 10

Rājbirāj is municipality in Saptari District, Nepal.

Density
1,255/km²
people per km²
Founded
1950

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 Rājbirāj reaches about 32°C in the afternoon and slips back to 26°C overnight — a 6°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)
13226
23226
33226
43226
53226
63226
73226
83226
93226
103226
113226
123226
133226
143226
153226
163226
173226
183225
193225
203225
213225
223225
233225
243225
253225
263225
273225
283225
293225
303225

How September really feels in Rājbirāj

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
23 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.

Rājbirāj 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
Jan23° / 11°121.610.58.9
Feb27° / 14°141.911.18.2
Mar33° / 19°162.711.84.8
Apr36° / 23°406.812.62.4
May35° / 25°12113.913.32.3
Jun33° / 26°29523.313.62.3
Jul32° / 26°42729.113.52.2
Aug32° / 26°34529.112.92.2
Sep32° / 26°30823.812.22.8
Oct31° / 22°766.911.45.1
Nov29° / 17°30.510.77.5
Dec25° / 13°40.510.49.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% 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 63%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12080
22080
32377
42377
52575
62575
72773
82872
93070
103070
113268
123367
133367
143565
153565
163664
173664
183763
193862
203961
214159
224258
234456
244753
254852
265050
275248
285446
295644
305941

Chance of precipitation in September

Any precipitation

Rājbirāj gets around 308 mm of rain over 23.8 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 79% and peaks near 91% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
191
291
390
490
589
688
787
886
986
1085
1184
1283
1382
1482
1581
1680
1780
1879
1978
2076
2175
2274
2372
2471
2569
2667
2765
2863
2961
3058

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 91% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
10199
20199
30199
40298
50298
60298
70298
80298
90298
100397
110397
120397
130496
140496
150595
160694
170793
180892
190991
2011089
2111287
2211386
2311485
2411683
2511782
2611980
2712178
2812376
2912574
3012871

Wind in September

Winds average 9 km/h in September.

Across September, daily wind ranges from about 7 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 36 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 48 minutes over September. Sunrise moves from 5:41 AM to 5:54 AM, and sunset from 6:14 PM to 5:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.65:416:14
212.55:426:13
312.55:426:12
412.55:436:11
512.45:436:10
612.45:436:09
712.45:446:07
812.45:446:06
912.35:456:05
1012.35:456:04
1112.35:466:03
1212.35:466:02
1312.25:466:00
1412.25:475:59
1512.25:475:58
1612.25:485:57
1712.15:485:56
1812.15:495:55
1912.15:495:53
2012.05:495:52
2112.05:505:51
2212.05:505:50
2312.05:515:49
2411.95:515:48
2511.95:525:46
2611.95:525:45
2711.95:535:44
2811.85:535:43
2911.85:535:42
3011.85:545:41

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.95 kWh/m².

For context, solar energy here swings from a low near 3.71 kWh/m² to a high of 6.31 kWh/m² in April across the year — September's 3.95 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.0Moderate
24.0Moderate
34.0Moderate
44.0Moderate
54.0Moderate
64.0Moderate
74.0Moderate
84.0Moderate
94.0Moderate
104.0Moderate
114.0Moderate
124.0Moderate
134.0Moderate
144.0Moderate
154.0Moderate
164.0Moderate
174.0Moderate
184.0Moderate
194.0Moderate
204.0Moderate
214.0Moderate
224.0Moderate
234.0Moderate
244.0Moderate
254.0Bright
264.0Bright
274.0Bright
284.1Bright
294.1Bright
304.1Bright
Planning a trip in September

Hazard calendar for Rājbirāj

In seasonPeak

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

Rājbirāj's monsoon runs June–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 Rājbirāj?

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
4.4
Beach & pool
9th-best month of the year

September is a weaker month for outdoor sightseeing in Rājbirāj.

What to pack for Rājbirāj in September

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

In September, Rājbirāj sees daytime highs around 32°C and nights near 26°C. Pack light clothes and rain gear. About 24 days see rain.

light clothesrain gear

UV index in Rājbirāj in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Rājbirāj peaks around July 19 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 20 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateVery highVery highModerateJul 19UV 11Jan 20UV 4
UV index (midday)Level
Jan4Moderate
Feb4Moderate
Mar8Very high
Apr7High
May8Very high
Jun7High
Jul11Extreme
Aug9Very high
Sep10Very high
Oct6High
Nov4Moderate
Dec4Moderate

Air quality in Rājbirāj 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 Rājbirāj is worst in January — around 243 µg/m³ PM2.5 (very unhealthy), about 5.3× the cleanest month (July, 46 µg/m³).

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

0306090120150180210240270JanFebMarAprMayJunJulAugSepOctNovDecVery unhealthyUnhealthyPoorUnhealthyVery unhealthyJan 12241 µg/m³Jul 1747 µg/m³
PM2.5 (µg/m³)Level
Jan243Very unhealthy
Feb196Very unhealthy
Mar138Unhealthy
Apr97Unhealthy
May75Unhealthy
Jun62Unhealthy
Jul46Poor
Aug58Unhealthy
Sep73Unhealthy
Oct124Unhealthy
Nov191Very unhealthy
Dec231Very unhealthy
Location & terrain

Where is Rājbirāj?

Rājbirāj sits at 26.5°N, 86.7°E, 89 m above sea level, in Nepal. The nearest listed city is Triyuga, 28 km away.

BiratnagarĪṭahari̇̄SirahaDharānDhankutā

Topography around Rājbirāj

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

Within 3 km, the terrain around Rājbirāj has only modest variations in elevation — a maximum elevation change of 27 m around an average of 83 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 378 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,952 m.

The land around Rājbirāj is covered by cropland (69%) within 3 km, cropland (67%) and trees (20%) within 16 km, and cropland (56%) and trees (38%) within 80 km.

3 km
27 m
16 km
378 m
80 km
2,952 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Triyuga 28 km · Lahān 33 km · Inaruwa 40 km · Biratnagar 53 km · Īṭahari̇̄ 54 km · Siraha 55 km · Dharān 61 km · Dhankutā 76 km

Nepal travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / D / M
230 V · 50 Hz
Prices
≈ 24% of US
price level, 2025
GDP per capita
$1,536
2025
Happiness
5.1 / 10
World Happiness, 2025
Safe drinking water
16%
of population, 2024
Homicide rate
2.1
per 100k, 2020
Road deaths
16.3
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
Moderate
EF EPI 514
Religion
Hindu 81%Buddhist 8%Muslim 5%Kirat 3%

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 Rājbirāj (26.5397°, 86.748°, elevation 89 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).