Climate and average weather in Akaiwa

In Akaiwa, the summers are muggy, hot, showery, and partly cloudy and the winters are cool and partly cloudy.

Best: mid April to mid June

Over the course of the year, the temperature in Akaiwa typically varies from 2°C to 33°C, and is rarely below -2°C or above 37°C. August is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Akaiwa for warm-weather activities are from mid April to mid June and late September to mid November.

Hottest
Aug
33°
Coldest
Jan
Wettest
Jul
187 mm
Driest
Jan
40 mm
Rain / yr
1264 mm
107 wet days
Daylight
9.7–14.3 h
shortest–longest
Elevation
47 m
34.8°N
Clearest
Dec
51% cloud

Akaiwa weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around mid April to mid June.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Akaiwa, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 3.2 months, from June 19 to September 23, with daily high temperatures above 27°C. The hottest month of the year in Akaiwa is August, with an average high of 33°C and low of 25°C.

The cool season lasts 3.4 months, from December 3 to March 16, with daily high temperatures below 14°C. The coldest month of the year in Akaiwa is January, with an average low of 2°C and high of 10°C.

Days typically run about 8°C warmer than nights year-round.

10°20°30°40°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan102
Feb112
Mar145
Apr2010
May2415
Jun2720
Jul3124
Aug3325
Sep2921
Oct2314
Nov188
Dec124

How hot and cold Akaiwa really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Akaiwa feels like about 38°C (around August 5). About 64 days a year carry some heat stress, peaking in August.

On the coldest nights, wind chill pulls the feels-like down to about -2°C (around January 28), with roughly 68 freezing days a year (feels-like at or below 0°C), worst in January.

10°20°30°40°JanFebMarAprMayJunJulAugSepOctNovDecdangerous heat
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan1010-22
Feb1111-12
Mar141425
Apr2020910
May24241515
Jun28272020
Jul35312424
Aug37332525
Sep30292121
Oct23231414
Nov171878
Dec121214

Average hourly temperature in Akaiwa

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on August afternoons, near 33°C, and coldest before dawn in January, near C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Akaiwa weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan10° / 405.50.39.92.4
Feb11° / 486.40.610.72.8
Mar14° / 929.30.111.74.3
Apr20° / 10°1089.7012.86.2
May24° / 15°1259.9013.86.8
Jun27° / 20°17212.2014.35.8
Jul31° / 24°18713.6014.14.0
Aug33° / 25°10810.3013.33.6
Sep29° / 21°16810.8012.25.5
Oct23° / 14°1147.7011.17.2
Nov18° / 576.1010.26.2
Dec12° / 465.30.19.73.7

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Akaiwa gets about 1264 mm of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.

The wetter season lasts 6.8 months, from around Mar 15 to Oct 6, peaking in June at about 51% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jan 1.

July is the wettest month by volume, with 187 mm over about 14 wet days; January is the driest, with 40 mm.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 30 · 51%Jan 1 · 15%
Rain on a day (%)Rain days
Jan186
Feb236
Mar309
Apr3210
May3210
Jun4112
Jul4314
Aug3410
Sep3511
Oct268
Nov206
Dec175

Monthly rainfall

Over a full year, Akaiwa collects about 1264 mm of rain across 107 wet days — roughly 105 mm in an average month.

It doesn’t fall evenly. July is the wettest month with 187 mm, while January is the driest at just 40 mm. The three wettest months alone bring about 42% of the year’s total, and some of the cold-season precipitation falls as snow.

050100150200JanFebMarAprMayJunJulAugSepOctNovDec4048921081251721871081681145746
Rainfall (mm)Rain daysSnow days
Jan4060
Feb4861
Mar9290
Apr108100
May125100
Jun172120
Jul187140
Aug108100
Sep168110
Oct11480
Nov5760
Dec4650

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Akaiwa, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around September 25 and lasts for 4.8 months, ending around February 16. The clearest month is December, when the sky is clear, mostly clear, or partly cloudy 63% of the time on average.

The cloudier part of the year begins around April 11 and lasts for 4.4 months, ending around August 21. The cloudiest month is June, when it is overcast or mostly cloudy 75% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecDec 30 · 64%Jun 26 · 19%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan5545
Feb4951
Mar4753
Apr4753
May4258
Jun2575
Jul3268
Aug4852
Sep4852
Oct5842
Nov6040
Dec6337

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 8, brings about 14 h 18 min of light; the shortest, around January 1, only 9 h 42 min — a swing of roughly 4 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.97:165:10
Feb10.76:585:39
Mar11.76:226:05
Apr12.85:386:30
May13.85:066:55
Jun14.34:547:14
Jul14.15:067:13
Aug13.35:296:48
Sep12.25:526:05
Oct11.16:165:22
Nov10.26:454:54
Dec9.77:104:50

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Akaiwa averages about 9 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 3 and 14 days.

The sunnier stretch runs 5.5 months, from around Jul 30 to Jan 12. The sunniest month is October, with roughly 13 sunny days (mixed).

The greyest month is June, down near 4 sunny days — about 66% fewer than the October peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergloomymixedbrightOct 2414 daysJun 263 days
Sunny daysSky
Jan9Mixed
Feb7Gloomy
Mar9Mixed
Apr9Mixed
May9Mixed
Jun4Gloomy
Jul6Gloomy
Aug10Mixed
Sep9Mixed
Oct13Mixed
Nov12Mixed
Dec12Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Akaiwa, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.4 months, from around May 29 to October 8. The muggiest month is July, when the air feels humid, muggy or worse about 100% of the time.

The most comfortable stretch runs from around October 9 to May 28, and March is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecMar 9 · 100%Jul 14 · 0%miserablehumidcomfortableoppressivedrymuggycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan10000000
Feb10000000
Mar9910000
Apr84123100
May512916400
Jun9182830150
Jul005245516
Aug015195421
Sep8152425243
Oct552215620
Nov9172000
Dec9900000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Akaiwa is typically calm, near 9 km/h, and varies little with the seasons.

The windier part of the year lasts 5.3 months, from around Nov 26 to May 4. The windiest month is January, averaging about 11 km/h (calm).

The calmer part of the year runs from around May 5 to Nov 25, with July the calmest month at about 8 km/h.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeJan 25 · 11 km/hJul 13 · 8 km/h
Wind speed (km/h)Feels
Jan11calm
Feb11calm
Mar10calm
Apr10calm
May9calm
Jun8calm
Jul8calm
Aug8calm
Sep9calm
Oct9calm
Nov9calm
Dec10calm

Hazard calendar for Akaiwa

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

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

Akaiwa's rainy season runs March–October, when most of the year's rain falls.

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

Best time to visit Akaiwa

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Akaiwa throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late April, Akaiwa is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best times of year to visit Akaiwa for general outdoor tourist activities run from mid April to mid June and again from late September to mid November, with a peak score in the third week of October.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationOct 16 · 7.4

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan2.4poor
Feb2.8poor
Mar4.3fair
Apr6.1good
May6.8good
Jun5.7good
Jul4.1fair
Aug3.7fair
Sep5.5fair
Oct7.2good
Nov6.1good
Dec3.7fair

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Akaiwa for hot-weather activities is from mid May to late October, with a peak score in the third week of September.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationSep 16 · 6.7

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Akaiwa, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around August (highs near 33°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 10°C), pack a warm layer.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Akaiwa sees daytime highs around 33°C and nights near 25°C. Pack light clothes. Worth having: rain gear and sun protection. About 10 days see rain.

Sea temperature near Akaiwa

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea at the nearest coast (about 38 km away) is warmest in August at about 27°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 7 to Nov 12 — about 5.2 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May17Cool
Jun21Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct24Refreshing
Nov20Cool
Dec16Cool

UV index (midday) in Akaiwa by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Akaiwa peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 highVery highModerateJul 13UV 10Dec 22UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Average hourly UV index in Akaiwa

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in July the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb3.50
Mar5.50
Apr73.5
May84.5
Jun8.55.5
Jul8.56
Aug7.55
Sep7.55
Oct5.50
Nov2.50
Dec00

Air quality in Akaiwa by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Akaiwa is worst in April — around 23 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (October, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1422 µg/m³Oct 1613 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb17Moderate
Mar21Moderate
Apr23Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug15Moderate
Sep13Moderate
Oct12Moderate
Nov13Moderate
Dec13Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayReliably frost-free (≥90%)

Akaiwa is mild enough that a frost-free day stays more likely than not even in midwinter. Nights are reliably above freezing from about March 16 to December 11 (271 days); outside that window a hard frost is an occasional risk.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecreliably frost-freeMar 1690%Dec 1190%
Frost-free chance (%)Frost nights
Jan7531
Feb7428
Mar9015
Apr990
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov990
Dec8818

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Akaiwa banks about 2,759 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar9
Apr140
May294
Jun398
Jul539
Aug582
Sep443
Oct269
Nov85
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Akaiwa receives about 4.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.4 and 5.8 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 11 to Sep 19. The brightest month is May, averaging about 5.7 kWh/m² (bright).

The dimmest month is December, down near 2.5 kWh/m² — roughly 57% less than the May peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseMay 225.8 kWhDec 142.4 kWh
Solar energy (kWh/m²)Level
Jan2.7Moderate
Feb3.4Moderate
Mar4.4Bright
Apr5.4Bright
May5.7Bright
Jun5.2Bright
Jul5.3Bright
Aug5.5Bright
Sep4.3Bright
Oct3.6Moderate
Nov2.8Moderate
Dec2.4Moderate

Where is Akaiwa?

Akaiwa sits at 34.8°N, 134.0°E, 47 m above sea level, in Japan. The nearest listed city is Okayama, 20 km away.

Topography around Akaiwa

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

Within 3 km, the terrain around Akaiwa has significant variations in elevation — a maximum elevation change of 251 m around an average of 102 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 518 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,692 m.

The land around Akaiwa is covered by trees (74%) within 3 km, trees (76%) within 16 km, and trees (65%) and water (23%) within 80 km.

3 km
251 m
16 km
518 m
80 km
1,692 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Okayama 20 km · Bizen 20 km · Setouchi 20 km · Hayashino 24 km · Tsuyama 27 km · Sōja 29 km · Kamigōri 32 km · Tamano 33 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 Akaiwa (34.8099°, 134.0215°, elevation 47 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).