Climate and average weather in Chikuma

In Chikuma, the summers are humid, warm, wet, and partly cloudy and the winters are very cold, snowy, and partly cloudy.

Best: late April to late October

Over the course of the year, the temperature in Chikuma typically varies from -7°C to 27°C, and is rarely below -11°C or above 30°C. August is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Chikuma for warm-weather activities is from late April to late October.

Hottest
Aug
27°
Coldest
Jan
-7°
Wettest
Jul
338 mm
Driest
Feb
129 mm
Rain / yr
2445 mm
224 wet days
Daylight
9.5–14.5 h
shortest–longest
Elevation
388 m
36.5°N
Clearest
Nov
59% cloud

Chikuma 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 late April to late October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.8 months, from June 3 to September 25, with daily high temperatures above 21°C. The hottest month of the year in Chikuma is August, with an average high of 27°C and low of 18°C.

The cool season lasts 3.3 months, from December 5 to March 14, with daily high temperatures below 6°C. The coldest month of the year in Chikuma is January, with an average low of -7°C and high of 1°C.

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

-10°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan1-7
Feb2-6
Mar6-2
Apr133
May199
Jun2214
Jul2518
Aug2718
Sep2314
Oct178
Nov101
Dec4-4

How hot and cold Chikuma 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 coldest nights, wind chill pulls the feels-like down to about -10°C (around February 1), with roughly 149 freezing days a year (feels-like at or below 0°C) 19 of them bitterly cold — worst in February.

-10°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan11-10-7
Feb22-9-6
Mar66-5-2
Apr131313
May191989
Jun22221414
Jul25251818
Aug27271818
Sep22231414
Oct171778
Nov101001
Dec44-7-4

Average hourly temperature in Chikuma

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 27°C, and coldest before dawn in January, near -7°C.

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

Chikuma 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 / -7°15220.121.79.80.0
Feb / -6°12916.716.910.60.0
Mar / -3°18017.814.111.70.5
Apr13° / 15815.53.912.93.1
May19° / 19316.40.113.95.1
Jun22° / 14°28820.6014.44.7
Jul25° / 18°33823.2014.24.6
Aug27° / 18°22519.7013.45.1
Sep23° / 14°25619012.25.1
Oct17° / 22318.50.211.14.3
Nov10° / 14916.85.310.12.1
Dec / -4°15519.717.39.60.1

Chance of rain

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

Chikuma gets about 2445 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.1 months, from around Jun 7 to Oct 9, peaking in July at about 80% chance on a given day. The drier stretch runs the rest of the year, bottoming out around May 1.

July is the wettest month by volume, with 338 mm over about 23 wet days; February is the driest, with 129 mm. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%70%80%90%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJul 4 · 80%May 1 · 49%
Rain on a day (%)Rain days
Jan6520
Feb6117
Mar5618
Apr5216
May5316
Jun6921
Jul7423
Aug6420
Sep6419
Oct5819
Nov5717
Dec6320

Monthly rainfall

Over a full year, Chikuma collects about 2445 mm of rain across 224 wet days — roughly 204 mm in an average month.

It doesn’t fall evenly. July is the wettest month with 338 mm, while February is the driest at just 129 mm. The three wettest months alone bring about 36% of the year’s total, and some of the cold-season precipitation falls as snow.

050100150200250300350400JanFebMarAprMayJunJulAugSepOctNovDec152129180158193288338225256223149155
Rainfall (mm)Rain daysSnow days
Jan1522022
Feb1291717
Mar1801814
Apr158164
May193160
Jun288210
Jul338230
Aug225200
Sep256190
Oct223190
Nov149175
Dec1552017

Snow in Chikuma

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.

Chikuma averages about 80 snowy days a year. Snow season runs roughly Oct 25 to May 4 — about 6.3 months.

January is snowiest, with roughly 21 days of snow and an estimated 139 cm of snowfall. Over the year that adds up to an estimated 507 cm of snow.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 21
Snow daysSnowfall (cm)
Jan22139
Feb17124
Mar1493
Apr419
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov524
Dec17106

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Chikuma, 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 10 and lasts for 3.2 months, ending around January 15. The clearest month is November, when the sky is clear, mostly clear, or partly cloudy 50% of the time on average.

The cloudier part of the year begins around May 17 and lasts for 4.8 months, ending around October 9. The cloudiest month is June, when it is overcast or mostly cloudy 78% 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%JanFebMarAprMayJunJulAugSepOctNovDecNov 1 · 53%Jun 28 · 16%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearer
Clearer (%)Cloudier (%)
Jan4060
Feb4357
Mar4852
Apr4753
May3961
Jun2278
Jul2575
Aug3664
Sep3367
Oct4456
Nov5050
Dec4357

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 12, brings about 14 h 30 min of light; the shortest, around January 1, only 9 h 30 min — a swing of roughly 5 hours.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.87:044:50
Feb10.66:445:21
Mar11.76:065:49
Apr12.95:206:16
May13.94:466:42
Jun14.44:337:02
Jul14.24:457:01
Aug13.45:106:34
Sep12.25:355:49
Oct11.16:015:04
Nov10.16:324:34
Dec9.66:584:29

Sunny days

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

Chikuma averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 10 days.

The sunnier stretch runs 2.7 months, from around Oct 12 to Dec 31. The sunniest month is November, with roughly 9 sunny days (mixed).

The greyest month is June, down near 3 sunny days — about 64% fewer than the November peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergloomymixedNov 410 daysJun 272 days
Sunny daysSky
Jan6Gloomy
Feb6Gloomy
Mar9Mixed
Apr9Mixed
May8Gloomy
Jun3Gloomy
Jul4Gloomy
Aug5Gloomy
Sep5Gloomy
Oct7Gloomy
Nov9Mixed
Dec7Gloomy

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

The more humid part of the year lasts 3.2 months, from around June 18 to September 23. The muggiest month is August, when the air feels humid, muggy or worse about 91% of the time.

The most comfortable stretch runs from around September 24 to June 17, and April 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%JanFebMarAprMayJunJulAugSepOctNovDecApr 21 · 100%Aug 5 · 3%muggycomfortabledryhumidcomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)
Jan100000
Feb100000
Mar100000
Apr100000
May94600
Jun4534192
Jul2155429
Aug284347
Sep2929339
Oct871120
Nov100000
Dec100000

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 Chikuma is steady company: average speeds sit near 6 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmFeb 16 · 7 km/hJul 16 · 4 km/h
Wind speed (km/h)Feels
Jan7calm
Feb7calm
Mar7calm
Apr6calm
May6calm
Jun5calm
Jul4calm
Aug5calm
Sep5calm
Oct5calm
Nov6calm
Dec7calm

Best time to visit Chikuma

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid October, Chikuma is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

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 time of year to visit Chikuma for general outdoor tourist activities is from late April to late October, with a peak score in the second week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 10 · 5.2

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
Jan0.0poor
Feb0.0poor
Mar0.5poor
Apr3.0poor
May5.0fair
Jun4.7fair
Jul4.6fair
Aug5.1fair
Sep5.1fair
Oct4.3fair
Nov2.1poor
Dec0.1poor

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 Chikuma for hot-weather activities is from mid July to mid September, with a peak score in the first week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 7 · 5.2

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 Chikuma, 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 27°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 1°C), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Chikuma sees daytime highs around 27°C and nights near 18°C. Pack rain gear. Worth having: light clothes and sun protection. About 20 days see rain.

Sea temperature near Chikuma

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 67 km away) is warmest in August at about 27°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 20 to Nov 1 — about 4.4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb11Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun20Cool
Jul23Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec15Cool

UV index (midday) in Chikuma 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 Chikuma peaks around July 20 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 highExtremeVery highModerateJul 20UV 10Dec 21UV 2
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Very high
Jul10Extreme
Aug10Extreme
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Average hourly UV index in Chikuma

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
Feb40
Mar5.50
Apr73.5
May85
Jun8.56
Jul8.56
Aug85.5
Sep7.55
Oct5.50
Nov2.50
Dec00

Air quality in Chikuma 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 Chikuma is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1721 µg/m³Dec 1510 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar20Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug13Moderate
Sep12Good
Oct11Good
Nov11Good
Dec10Good
Almanac & agriculture

Growing season

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

The growing season in Chikuma typically lasts about 234 days, from around April 3 to November 22 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 25 to November 1.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonFeb 2610%Apr 350%Apr 2590%Nov 190%Nov 2250%Dec 1610%
Frost-free chance (%)Frost nights
Jan331
Feb528
Mar2431
Apr7424
May990
Jun1000
Jul1000
Aug1000
Sep1000
Oct980
Nov6528
Dec1331

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. Chikuma banks about 1,420 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

05001,0001,500JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar0
Apr2
May113
Jun231
Jul360
Aug387
Sep254
Oct74
Nov0
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.

Chikuma receives about 4.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.3 and 5.8 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 5.7 kWh/m² (bright).

The dimmest month is December, down near 2.3 kWh/m² — roughly 60% less than the May peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseMay 245.8 kWhDec 122.3 kWh
Solar energy (kWh/m²)Level
Jan2.6Moderate
Feb3.5Moderate
Mar4.5Bright
Apr5.4Bright
May5.7Bright
Jun5.2Bright
Jul4.9Bright
Aug5.0Bright
Sep4.0Moderate
Oct3.3Moderate
Nov2.6Moderate
Dec2.3Moderate

Where is Chikuma?

Chikuma sits at 36.5°N, 138.1°E, 388 m above sea level, in Japan. The nearest listed city is Sakaki, 11 km away.

Topography around Chikuma

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

Within 3 km, the terrain around Chikuma has large variations in elevation — a maximum elevation change of 635 m around an average of 539 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,102 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,130 m.

The land around Chikuma is covered by trees (54%) and artificial surfaces (22%) within 3 km, trees (78%) within 16 km, and trees (78%) within 80 km.

3 km
635 m
16 km
1,102 m
80 km
3,130 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Sakaki 11 km · Nagano 16 km · Ōmachi 20 km · Ueda 22 km · Suzaka 24 km · Hotaka 28 km · Kamimaruko 28 km · Toyoshina 30 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 Chikuma (36.5271°, 138.0894°, elevation 388 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. 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).