Ryūgasaki weather in September

In September, Ryūgasaki sees average daytime highs of 27°C and overnight lows near 21°C, with 169 mm of rain across 14.2 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 29°C in the first days to 24°C by the end. The sky is clear or mostly clear about 19% of the time in September, and the air most often feels muggy.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Ryūgasaki's 9th-clearest and 5th-windiest month. For the whole year in context, see Ryūgasaki's year-round climate.

Daytime high
27°
3rd warmest
Overnight low
21°
10th coldest
Rainfall
169 mm
14.2 wet days
Daylight
12 h 12 min
5:27 AM – 5:40 PM
Cloud cover
68%
9th clearest
Wind
10 km/h
5th windiest
Solar energy
3.86 kWh/m²
Travel score
5.5
out of 10

Ryūgasaki is city in Ibaraki Prefecture, Japan.

Density
1,091/km²
people per km²
Founded
1954

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 29°C in the first days to 24°C by the end.

A typical September day in Ryūgasaki reaches about 27°C in the afternoon and slips back to 21°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 31°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12923
22923
32923
42923
52923
62923
72922
82822
92822
102822
112822
122822
132821
142721
152721
162721
172721
182620
192620
202620
212620
222620
232519
242519
252519
262519
272519
282418
292418
302418

How September really feels in Ryūgasaki

Once humidity and wind are folded in, September averages 2 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
2
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.

Ryūgasaki weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 667.31.19.82.1
Feb10° / 647.91.710.62.3
Mar13° / 11312.40.711.73.6
Apr18° / 10°10812.3012.95.5
May23° / 15°12912013.96.3
Jun26° / 19°15014.4014.45.6
Jul29° / 23°15814.8014.24.5
Aug31° / 24°11912.9013.44.2
Sep27° / 21°16914.2012.25.5
Oct21° / 15°19112.6011.16.1
Nov16° / 919.8010.15.2
Dec11° / 628.10.19.63.2

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 18% of September, with mostly cloudy or overcast conditions the remaining 63%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14060
24060
34060
44060
54060
64159
74060
84060
93961
103961
113961
123961
133862
143763
153664
163664
173664
183565
193565
203565
213565
223466
233466
243565
253565
263565
273664
283664
293664
303763

Chance of precipitation in September

Any precipitation

Ryūgasaki gets around 169 mm of rain over 14.2 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 48% and peaks near 49% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
146
247
348
448
548
649
749
849
949
1049
1149
1249
1349
1448
1548
1648
1748
1848
1947
2047
2147
2247
2347
2446
2546
2646
2746
2846
2946
3046

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 30% of days. Sticky, muggy-or-worse air turns up on roughly 64% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1018295012
2019304912
3019304811
40110314810
50111314710
6021132469
7021232459
8031332438
9031432428
10141533417
11151633396
12161733376
13171833365
14281933345
15292033314
163102133294
173112333273
184122432253
195132532233
205152631212
216162830192
227172929172
237183028151
248193127131
259193326111
2610203425101
271120352481
281221362371
291321372261
301421382150

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 10 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
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 5:15 AM to 5:38 AM, and sunset from 6:03 PM to 5:19 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:156:03
212.85:166:01
312.75:176:00
412.75:175:59
512.65:185:57
612.65:195:56
712.65:205:54
812.55:215:53
912.55:215:51
1012.55:225:49
1112.45:235:48
1212.45:245:46
1312.35:255:45
1412.35:255:43
1512.35:265:42
1612.25:275:40
1712.25:285:39
1812.15:285:37
1912.15:295:36
2012.15:305:34
2112.05:315:33
2212.05:325:31
2312.05:325:30
2411.95:335:28
2511.95:345:26
2611.85:355:25
2711.85:365:23
2811.85:375:22
2911.75:375:20
3011.75:385:19

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.86 kWh/m².

For context, solar energy here swings from a low near 2.35 kWh/m² to a high of 5.27 kWh/m² in May across the year — September's 3.86 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.4Bright
34.3Bright
44.3Bright
54.3Bright
64.2Bright
74.2Bright
84.2Bright
94.1Bright
104.1Bright
114.0Bright
124.0Bright
134.0Moderate
143.9Moderate
153.9Moderate
163.8Moderate
173.8Moderate
183.7Moderate
193.7Moderate
203.7Moderate
213.6Moderate
223.6Moderate
233.5Moderate
243.5Moderate
253.5Moderate
263.4Moderate
273.4Moderate
283.4Moderate
293.3Moderate
303.3Moderate
Planning a trip in September

Hazard calendar for Ryūgasaki

In seasonPeak

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

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

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

Is September a good time to visit Ryūgasaki?

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

5.5
Sightseeing
4th-best month of the year
5.7
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Ryūgasaki for sightseeing.

What to pack for Ryūgasaki in September

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

In September, Ryūgasaki sees daytime highs around 27°C and nights near 21°C. Pack rain gear. Worth having: light clothes. About 14 days see rain.

rain gearlight clothes

Sea temperature near Ryūgasaki in September

The nearest coast averages about 25°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 41 km away) is warmest in August at about 26°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 7 to Nov 3 — about 4.9 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec16Cool

UV index in Ryūgasaki in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ryūgasaki peaks around July 21 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJul 21UV 10Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Ryūgasaki 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 Ryūgasaki is worst in March — around 25 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2425 µg/m³Dec 1914 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar25Moderate
Apr25Moderate
May24Moderate
Jun19Moderate
Jul16Moderate
Aug15Moderate
Sep15Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Ryūgasaki?

Ryūgasaki sits at 35.9°N, 140.2°E, 8 m above sea level, in Japan. The nearest listed city is Fujishiro, 6.0 km away.

Topography around Ryūgasaki

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

Within 3 km, the terrain around Ryūgasaki has only modest variations in elevation — a maximum elevation change of 39 m around an average of 6 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 54 m; within 80 km, large variations in elevation — a maximum elevation change of 840 m.

The land around Ryūgasaki is covered by cropland (59%) and artificial surfaces (25%) within 3 km, cropland (36%), trees (30%) and artificial surfaces (22%) within 16 km, and water (28%), trees (25%) and artificial surfaces (25%) within 80 km.

3 km
39 m
16 km
54 m
80 km
840 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Fujishiro 6.0 km · Fukawa 6.0 km · Inzai 7.0 km · Ushiku 9.0 km · Ajiki 9.0 km · Toride 9.0 km · Edosaki 13 km · Inashiki 14 km

Japan travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
100 V · 50 / 60 Hz
Prices
≈ 65% of US
price level, 2025
GDP per capita
$35,951
2025
Happiness
6.1 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.2
per 100k, 2023
Road deaths
3.6
per 100k/yr, 2019
Income group
High
World Bank
English
Very low
EF EPI 446
Religion
Shintoism 49%Buddhism 46%other 4%Christianity 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 Ryūgasaki (35.9°, 140.1833°, elevation 8 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).