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1,216 places · sun position · panel angle

Solar data for Japan

Across the 1,216 places in Japan the best fixed tilt for solar panels runs from 17° in Miyakojima to 41° in Kushiro, and flat ground gets 3.2 to 4.3 peak sun hours a day. Every number is computed for each place.

Solar power in Japan at a glance

Averages over 1,216 places with climate data, for a fixed array facing south.

Best panel angle31°average, facing south
Peak sun hours3.78a day on flat ground
1 kWp makes1,284kWh a year at the best angle
Off-grid angle49°average, for the darkest month
TokyoMiyakojima (most sun)
  • 3.17–3.40
  • 3.40–3.64
  • 3.64–3.87
  • 3.87–4.10
  • 4.10–4.34

Peak sun hours a day on flat ground. Each dot is one place (the 900 largest). 2 far-off places lie outside the frame.

The sunniest place in Japan is Miyakojima (Okinawa) with 4.34 peak sun hours a day on flat ground; the least sunny are Wakkanai and one other place with 3.17. A 1 kWp array at its best angle makes from 1,108 kWh a year in Ōmagari to 1,397 kWh in Chūō — 1,284 kWh on average.

The best year-round tilt runs from 17° in Miyakojima to 41° in Kushiro. Off-grid systems are sized for the darkest month and do better steeper, at 49° on average: at 70° that month brings 1.51 kWh per kWp a day in Yoichi and 2.62 kWh in Abashiri.

Size an off-grid system or open any place below for its sun path, monthly table and tilt curve.

Sunniest places in Japan

Ranked by peak sun hours on flat ground: the yearly average of a day's sunshine energy (NASA POWER climatology). Output: 1 kWp at its best year-round angle.

RankPlaceRegionSun hours/daykWh per kWp a yearBest tilt
1MiyakojimaOkinawa4.341,30217°
2HiraraOkinawa4.331,30017°
3YaeseOkinawa4.311,30519°
3NanjōOkinawa4.311,30519°
5ItomanOkinawa4.301,30219°
6YonabaruOkinawa4.291,30019°
6KanegusukuOkinawa4.291,29919°
6TomigusukuOkinawa4.291,29819°
9NakagusukuOkinawa4.281,29819°
9NahaOkinawa4.281,29619°

Least sunny places in Japan

RankPlaceRegionSun hours/daykWh per kWp a yearBest tilt
1212MinamishibetsuchōHokkaido3.221,14636°
1213ShibetsuHokkaido3.211,14636°
1214NayoroHokkaido3.181,13636°
1215MakubetsuHokkaido3.171,14637°
1215WakkanaiHokkaido3.171,14237°

Solar by region in Japan

Averages of the places in each region, sunniest first. Darkest month: what 1 kWp of off-grid panels at 70° makes a day in the worst month of the year.

RegionPlacesSun hours/daykWh per kWp a yearBest tiltDarkest month at 70°Sunniest place
Okinawa244.281,29519°1.98 kWhMiyakojima
Tokushima133.991,33430°2.18 kWhYakami
Shizuoka353.981,37433°2.21 kWhKosai
Kochi123.981,32630°2.07 kWhMuroto-misakicho
Kagawa133.971,32830°2.23 kWhHigashikagawa
Kagoshima293.971,27927°1.87 kWhNaze
Wakayama153.951,32030°2.16 kWhKushimoto
Miyazaki163.951,30429°1.85 kWhNichinan
Ehime183.941,30829°2.13 kWhMishōhirajō
Kumamoto253.911,28729°1.98 kWhHitoyoshi
Aichi533.901,32932°2.25 kWhShinshiro
Yamanashi193.891,38736°2.23 kWhFujikawaguchiko
Kanagawa333.891,35734°2.17 kWhYugawara
Oita163.881,28730°2.04 kWhSaiki
Mie213.881,31331°2.19 kWhKumano
Nagasaki173.881,25727°2.07 kWhTsushima
Okayama163.871,28529°2.28 kWhTamano
Tokyo513.861,35835°2.19 kWhHachiōji
Nara223.861,29830°2.21 kWhŌuda-yamaguchi
Hiroshima243.851,27529°2.24 kWhFukuyama
Saga153.851,25628°2.08 kWhKashima
Saitama633.841,35735°2.21 kWhIruma
Fukuoka523.841,26129°2.11 kWhŌmuta
Osaka383.831,28230°2.23 kWhHannan
Ibaraki533.821,33835°2.24 kWhFunaishikawa
Chiba473.821,30933°2.20 kWhFuttsu
Gunma223.811,35035°2.24 kWhŌwa
Yamaguchi163.801,24628°2.17 kWhYanai
Hyōgo453.801,26530°2.25 kWhFukura
Gifu323.801,29431°2.26 kWhNakatsugawa
Tochigi263.781,33635°2.24 kWhAshikaga
Nagano293.771,31533°2.27 kWhIida
Shiga173.751,25830°2.23 kWhHino
Kyoto223.721,23729°2.22 kWhKizugawa
Shimane93.701,20528°2.09 kWhHamada
Fukui133.641,20329°2.14 kWhTsuruga
Fukushima233.621,26534°2.23 kWhIwaki
Tottori83.591,17228°2.04 kWhKōge
Ishikawa173.591,17728°1.81 kWhWajima
Toyama183.581,18729°1.94 kWhKamiichi
Miyagi273.541,23234°2.24 kWhIshinomaki
Niigata323.511,16829°1.91 kWhShiozawa
Iwate213.471,21234°2.27 kWhKamaishi
Yamagata163.431,16331°2.05 kWhYonezawa
Akita183.341,12231°1.70 kWhOga
Hokkaido493.311,19036°2.01 kWhKushiro
Aomori163.311,14033°1.92 kWhHachinohe

Largest places in Japan at a glance

PlaceLatitudeBest tiltOff-grid tiltSun hours/day (flat)
Tokyo35.7° N34°41°3.86
Yokohama35.4° N34°41°3.87
Osaka34.7° N30°54°3.81
Nagoya35.2° N32°48°3.86
Sapporo43.1° N35°66°3.30
Fukuoka33.6° N28°56°3.83
Kawasaki35.5° N34°42°3.86
Kobe34.7° N30°54°3.84
Kyoto35.0° N30°58°3.74
Saitama35.9° N35°41°3.84
Hiroshima34.4° N29°57°3.82
Sendai38.3° N34°58°3.53
Chiba35.6° N33°42°3.82
Kitakyushu33.9° N28°56°3.83
Sakai34.6° N30°52°3.84
Niigata37.9° N28°57°3.46
Hamamatsu34.7° N32°38°4.04
Ōta35.6° N34°42°3.86
Kumamoto32.8° N29°43°3.90
Aihara35.6° N35°39°3.88

Daylight and clock time in Japan

In Wakkanai (45.4° N), the northernmost place, the longest day of the year lasts 15 h 40 min and the shortest 8 h 43 min; in Ishigaki (24.3° N), the southernmost, 13 h 39 min and 10 h 38 min. Japan does not use daylight saving time: the clocks stay the same all year.

Time zonePlacesUTC offsetClocks change in 2026
Asia/Tokyo1,216UTC+9no daylight saving time

Questions about solar in Japan

What is the best angle for solar panels in Japan?
Facing south, between 17° and 41° depending on the place — 31° on average over 1,216 places. Off-grid systems that must get through the darkest month do better steeper, at about 49° on average.
How many peak sun hours does Japan get?
From 3.2 hours a day in Wakkanai to 4.3 in Miyakojima on flat ground, averaged over the year; 3.8 on average.
How much electricity does 1 kWp of solar panels produce in Japan?
About 1,284 kWh a year at the best fixed angle on average, from 1,108 kWh in Ōmagari to 1,397 kWh in Chūō. These are long-term climate averages; a single year can be several per cent higher or lower.
Where is the sunniest place in Japan?
Miyakojima (Okinawa) gets the most sun of the 1,216 places: 4.34 peak sun hours a day on flat ground, so 1 kWp there makes about 1,302 kWh a year.
Does Japan use daylight saving time?
Japan does not use daylight saving time: the clocks stay the same all year.
How long is the longest day in Japan?
15 h 40 min in Wakkanai; the shortest day lasts 8 h 43 min in Wakkanai.

All places in Japan