Climate and average weather in Kodaira

In Kodaira, the summers are muggy, hot, wet, and partly cloudy and the winters are cool, snowy, and mostly clear.

Best: mid April to early July

Over the course of the year, the temperature in Kodaira typically varies from -0°C to 30°C, and is rarely below -4°C or above 34°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 Kodaira for warm-weather activities are from mid April to early July and early September to mid November.

Hottest
Aug
30°
Coldest
Jan
-0°
Wettest
Oct
215 mm
Driest
Dec
61 mm
Rain / yr
1589 mm
149 wet days
Daylight
9.6–14.4 h
shortest–longest
Elevation
79 m
35.7°N
Clearest
Jan
40% cloud

Kodaira 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 early July.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.1 months, from June 19 to September 21, with daily high temperatures above 25°C. The hottest month of the year in Kodaira is August, with an average high of 30°C and low of 24°C.

The cool season lasts 3.4 months, from December 3 to March 15, with daily high temperatures below 13°C. The coldest month of the year in Kodaira is January, with an average low of -0°C and high of 9°C.

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

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan90
Feb101
Mar134
Apr189
May2214
Jun2519
Jul2923
Aug3024
Sep2620
Oct2114
Nov168
Dec113

How hot and cold Kodaira 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, Kodaira feels like about 35°C (around August 6). About 42 days a year carry some heat stress, peaking in August.

On the coldest nights, wind chill pulls the feels-like down to about -4°C (around January 27), with roughly 82 freezing days a year (feels-like at or below 0°C), worst in January.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan99-30
Feb1010-31
Mar131314
Apr181889
May22221414
Jun25251919
Jul32292323
Aug34302424
Sep27262020
Oct21211414
Nov161678
Dec111103

Average hourly temperature in Kodaira

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 30°C, and coldest before dawn in January, near -0°C.

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

Kodaira 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
Jan / -0°697.52.59.91.9
Feb10° / 658.42.510.62.2
Mar13° / 12013.21.511.73.4
Apr18° / 12312.80.312.95.3
May22° / 14°13913.2013.96.1
Jun25° / 19°17715.4014.45.5
Jul29° / 23°18216.4014.24.6
Aug30° / 24°14215.5013.44.2
Sep26° / 20°20414.9012.25.5
Oct21° / 14°21513.7011.15.9
Nov16° / 9210.2010.15.0
Dec11° / 617.40.49.63.1

Chance of rain

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

Kodaira gets about 1589 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.5 months, from around May 8 to Oct 22, peaking in June at about 59% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 27.

October is the wettest month by volume, with 215 mm over about 14 wet days; December is the driest, with 61 mm. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%70%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 30 · 59%Dec 27 · 19%
Rain on a day (%)Rain days
Jan248
Feb318
Mar4113
Apr4313
May4213
Jun5215
Jul5216
Aug5016
Sep5015
Oct4414
Nov3410
Dec247

Monthly rainfall

Over a full year, Kodaira collects about 1589 mm of rain across 149 wet days — roughly 132 mm in an average month.

It doesn’t fall evenly. October is the wettest month with 215 mm, while December is the driest at just 61 mm. The three wettest months alone bring about 38% of the year’s total, and some of the cold-season precipitation falls as snow.

050100150200250JanFebMarAprMayJunJulAugSepOctNovDec69651201231391771821422042159261
Rainfall (mm)Rain daysSnow days
Jan6983
Feb6583
Mar120132
Apr123130
May139130
Jun177150
Jul182160
Aug142160
Sep204150
Oct215140
Nov92100
Dec6170

Snow in Kodaira

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Kodaira averages about 7 snowy days a year. Snow season runs roughly Dec 22 to Apr 5 — about 3.5 months.

January is snowiest, with roughly 2 days of snow and an estimated 21 cm of snowfall. Over the year that adds up to an estimated 52 cm of snow.

0246JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonJan 21
Snow daysSnowfall (cm)
Jan321
Feb321
Mar27
Apr01
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov00
Dec02

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Kodaira, 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 October 19 and lasts for 5.4 months, ending around April 1. The clearest month is January, when the sky is clear, mostly clear, or partly cloudy 71% of the time on average.

The cloudier part of the year begins around April 2 and lasts for 6.6 months, ending around October 18. The cloudiest month is June, when it is overcast or mostly cloudy 80% 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%JanFebMarAprMayJunJulAugSepOctNovDecJan 1 · 77%Jun 21 · 16%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan7129
Feb6139
Mar5050
Apr4456
May3565
Jun2080
Jul2674
Aug3763
Sep3664
Oct4654
Nov5842
Dec7129

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 10, brings about 14 h 24 min of light; the shortest, around January 1, only 9 h 36 min — a swing of roughly 4 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.96:564:46
Feb10.66:375:16
Mar11.76:005:43
Apr12.95:156:09
May13.94:426:35
Jun14.44:306:54
Jul14.24:426:54
Aug13.45:056:27
Sep12.25:305:43
Oct11.15:554:59
Nov10.16:254:30
Dec9.66:504:26

Sunny days

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

Kodaira averages about 10 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 20 days.

The sunnier stretch runs 4.9 months, from around Oct 20 to Mar 18. The sunniest month is January, with roughly 18 sunny days (bright).

The greyest month is June, down near 3 sunny days — about 83% fewer than the January peak.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedbrightbrilliantJan 120 daysJun 222 days
Sunny daysSky
Jan18Bright
Feb13Mixed
Mar10Mixed
Apr9Mixed
May7Gloomy
Jun3Gloomy
Jul5Gloomy
Aug7Gloomy
Sep6Gloomy
Oct10Mixed
Nov13Mixed
Dec18Bright

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 Kodaira, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.5 months, from around May 27 to October 10. The muggiest month is August, when the air feels humid, muggy or worse about 99% of the time.

The most comfortable stretch runs from around October 11 to May 26, 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 10 · 100%Aug 3 · 0%miserablehumidmuggycomfortabledryoppressivecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan10000000
Feb10000000
Mar9910000
Apr8991000
May463417300
Jun5193430110
Jul019265211
Aug016175719
Sep6122429272
Oct492717610
Nov9371000
Dec10000000

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.

Wind in Kodaira is steady company: average speeds sit near 9 km/hcalm — in every month of the year, with no meaningful windy or calm season.

051015JanFebMarAprMayJunJulAugSepOctNovDeccalmlight breezeApr 11 · 10 km/hNov 8 · 8 km/h
Wind speed (km/h)Feels
Jan9calm
Feb9calm
Mar10calm
Apr10calm
May10calm
Jun9calm
Jul8calm
Aug8calm
Sep9calm
Oct8calm
Nov8calm
Dec8calm

Hazard calendar for Kodaira

In seasonPeak

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

Kodaira 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

Best time to visit Kodaira

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late April, Kodaira 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 Kodaira for general outdoor tourist activities run from mid April to early July and again from early September to mid November, with a peak score in the last week of May.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationMay 27 · 6.2

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
Jan1.9poor
Feb2.2poor
Mar3.4poor
Apr5.3fair
May6.1good
Jun5.5good
Jul4.6fair
Aug4.2fair
Sep5.5fair
Oct5.9good
Nov5.0fair
Dec3.1poor

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 Kodaira for hot-weather activities is from late May to early October, with a peak score in the last week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 31 · 6.0

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 Kodaira, 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 30°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 9°C), pack a warm layer.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Kodaira sees daytime highs around 30°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 16 days see rain.

Sea temperature near Kodaira

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 37 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 (midday) in Kodaira 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 Kodaira peaks around July 20 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 20UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Average hourly UV index in Kodaira

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 5.5 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
Feb30
Mar4.50
Apr6.52.5
May7.54.5
Jun8.55.5
Jul8.55.5
Aug85.5
Sep74
Oct5.50
Nov2.50
Dec00

Air quality in Kodaira 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 Kodaira is worst in April — around 26 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1426 µg/m³Dec 1814 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb21Moderate
Mar25Moderate
Apr26Moderate
May24Moderate
Jun20Moderate
Jul17Moderate
Aug16Moderate
Sep16Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Kodaira typically lasts about 337 days, from around February 10 to January 12 — the span where a frost-free day is more likely than not. It is reliably frost-free from March 19 to December 8.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonFeb 1050%Mar 1990%Dec 890%Jan 1250%
Frost-free chance (%)Frost nights
Jan4931
Feb5728
Mar8717
Apr990
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov990
Dec8123

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. Kodaira banks about 2,428 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

01,0002,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar1
Apr106
May259
Jun357
Jul489
Aug526
Sep398
Oct233
Nov59
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.

Kodaira receives about 3.7 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 2.3 and 5.0 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 4 to Sep 11. The brightest month is May, averaging about 5.0 kWh/m² (bright).

The dimmest month is December, down near 2.4 kWh/m² — roughly 52% less than the May peak.

0123456JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightMay 225.0 kWhDec 32.3 kWh
Solar energy (kWh/m²)Level
Jan2.8Moderate
Feb3.5Moderate
Mar4.0Bright
Apr4.8Bright
May5.0Bright
Jun4.3Bright
Jul4.5Bright
Aug4.6Bright
Sep3.6Moderate
Oct2.9Moderate
Nov2.5Moderate
Dec2.3Moderate

Where is Kodaira?

Kodaira sits at 35.7°N, 139.5°E, 79 m above sea level, in Japan. The nearest listed city is Kokubunji, 3.0 km away.

Topography around Kodaira

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

Within 3 km, the terrain around Kodaira has only modest variations in elevation — a maximum elevation change of 41 m around an average of 77 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 209 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,737 m.

The land around Kodaira is covered by artificial surfaces (81%) within 3 km, artificial surfaces (73%) within 16 km, and trees (42%) and artificial surfaces (28%) within 80 km.

3 km
41 m
16 km
209 m
80 km
3,737 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Kokubunji 3.0 km · Higashimurayama 4.0 km · Koganei 4.0 km · Higashikurume 4.0 km · Tanashichō 5.0 km · Nishi-Tokyo-shi 5.0 km · Akitsu 5.0 km · Higashiyamato 5.0 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 Kodaira (35.726°, 139.4851°, elevation 79 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).