Solarposition.org

Gunma · Japan · 36.27° N · 139.25° E

Solar position in Sakai-nakajima

Sun position, daylight and the best solar panel angle for Sakai-nakajima — computed for 36.27° N, 139.25° E, 43 m above sea level.

Sunrise today05:58104° ESE
Sunset today16:55256° WSW
Best panel angle35°year-round, facing south
Off-grid angle38°best for the darkest month

The sun right now

Azimuth180.0°
Elevation41.7°
At solar noon, 11:26Open on the sun map

Sun in Sakai-nakajima today

Sunday, 25 October 2026 · local time UTC+9

EventTimeDirection / height
Astronomical dawn04:32sun 18° below horizon
Nautical dawn05:0212° below
Civil dawn05:326° below
Sunrise05:58104° ESE
Golden hour ends06:34sun 6° up
Solar noon11:2641.7° high
Golden hour starts16:19sun 6° up
Sunset16:55256° WSW
Civil dusk17:216° below
Nautical dusk17:5112° below
Astronomical dusk18:2118° below
Day length10 h 56 min

Sun path diagram for Sakai-nakajima

Where the sun stands in the sky: the centre is straight overhead, the outer ring is the horizon. Numbers mark local clock hours.

15°30°45°60°75°N30°60°E120°150°S210°240°W300°330°June solstice56789101112131415161718EquinoxDecember solstice78910111213141516Today
  • June solstice
  • Equinox
  • December solstice
  • Today

On the June solstice the sun reaches 77.2° at solar noon in Sakai-nakajima; on the December solstice only 30.3°. Sunrise swings from 60° ENE in June to 119° ESE in December — a 59° arc along the horizon.

Sunrise, sunset and sun height by month

Values for the 21st of each month, local clock time including daylight saving time.

MonthSunriseSolar noonSunsetDay lengthNoon elevation
January06:5111:5416:5710 h 06 min33.8°
February06:2411:5617:2911 h 05 min43.2°
March05:4511:5017:5512 h 09 min53.9°
April05:0211:4118:2113 h 19 min65.6°
May04:3211:3918:4614 h 14 min73.9°
June04:2511:4419:0314 h 38 min77.2°
July04:4111:4918:5714 h 16 min74.2°
August05:0511:4618:2613 h 21 min65.9°
September05:2911:3617:4212 h 12 min54.5°
October05:5511:2716:5911 h 05 min43.1°
November06:2511:2816:3110 h 06 min33.9°
December06:5011:4016:319 h 41 min30.3°

A year of daylight in Sakai-nakajima

Each column is one day of 2026. Bright: sun above the horizon; soft: civil twilight; line: solar noon. Steps are daylight saving time changes.

00:0003:0006:0009:0012:0015:0018:0021:0000:00JanFebMarAprMayJunJulAugSepOctNovDec

Best solar panel angle in Sakai-nakajima

Fixed array facing south (azimuth 180°). Energy per kWp from NASA POWER monthly climate, including clouds, temperature and snow reflection.

35°collects the most energy over a year: 1357 kWh per kWp.

38°gives the most in the darkest month — the one an off-grid system is sized for.

40%50%60%70%80%90%100%0°10°20°30°40°50°60°70°80°90°Best year-round 35°Best worst-month 38°70°Yearly energyWorst-month energy
  • Yearly energy
  • Worst-month energy
TiltkWh/kWp per yearShare of best yearOctober kWh/kWp/dayBest ÷ worst month
0°115285%2.542.3×
15°128895%2.981.6×
30°1353100%3.241.3×
35° year-round best1357100%3.291.3×
36° = latitude1357100%3.301.3×
38° off-grid best1356100%3.311.3×
45°134299%3.331.4×
60°125693%3.211.6×
70°116186%3.031.9×
90°89766%2.452.7×

A fixed array in Sakai-nakajima produces the most over a year at 35°. The design month for an off-grid system is October: at 38° it makes 3.31 kWh per kWp a day, and costs 0% of the yearly total. Why steep panels win winter.

Off-grid solar in Sakai-nakajima at 70°

Daily energy of 1 kWp by month. Bars: panels at 70°. Line: panels at 35° (year-round best).

012345January: 4.20 (70°)4.2JanFebruary: 4.13 (70°)4.1FebMarch: 3.69 (70°)3.7MarApril: 3.19 (70°)3.2AprMay: 2.72 (70°)2.7MayJune: 2.26 (70°)2.3JunJuly: 2.24 (70°)2.2JulAugust: 2.67 (70°)2.7AugSeptember: 2.75 (70°)2.8SepOctober: 3.03 (70°)3.0OctNovember: 3.54 (70°)3.5NovDecember: 3.81 (70°)3.8Dec35°
MonthSun hours, flatSun hours at 70°kWh/kWp/day at 70°at 35°Mean temp.
January snow2.604.624.203.80-1.4 °C
February snow3.294.554.134.08-0.5 °C
March4.114.143.694.273.2 °C
April4.843.673.194.279.0 °C
May5.203.222.724.0814.7 °C
June4.682.742.263.4818.8 °C
July4.552.752.243.3822.8 °C
August4.733.272.673.7523.7 °C
September3.793.312.753.4019.6 °C
October3.103.543.033.2913.4 °C
November2.614.023.543.407.3 °C
December2.314.243.813.451.5 °C
Year3.82 avg3.67 avg1161 kWh1357 kWh

Sizing example. To run a 1 kWh-per-day load through July on LiFePO4 batteries (charge controller, battery and inverter losses included) you need about 530 Wp of panels at 70°, versus 360 Wp at 35°. Here the lower tilt is the better winter choice — the sun stays high enough. Size your own system.

Row spacing in Sakai-nakajima

Distance between rows of 2 m long panels (slope length) so that no row shades the next between 10:00 and 14:00 solar time on the winter solstice.

4.4 mrow pitch at 70°

3.9 mrow pitch at 35°

Row spacing calculator

How Sakai-nakajima compares in Japan

Against the other 1,215 places in Japan with climate data, for a fixed array at its best angle.

664thof 1,216 places in Japan for sunshine, shared: 3.82 peak sun hours a day on flat ground.

+6%solar energy a year compared with the average place in Japan: 1,357 against 1,284 kWh per kWp.

+3 mindaylight on the longest day, compared with Tokyo: 14 h 38 min against 14 h 35 min.

35°best year-round tilt here; across Japan it runs from 17° in Miyakojima to 41° in Kushiro.

Of the 1,216 places in Japan, Miyakojima gets the most sun (4.34 peak sun hours a day) and Wakkanai and one other place the least (3.17); Sakai-nakajima ranks joint 664th. In its darkest month, July, 1 kWp of off-grid panels at 70° makes 2.24 kWh a day here, against 2.14 kWh on average in Japan. The shortest day lasts 9 h 41 min, −3 min compared with Tokyo.

The sunniest places in Japan

Solar forecast for Sakai-nakajima, next 48 hours

Expected output of 1 kWp at 70°, computed from the ICON-EU weather model of the Deutscher Wetterdienst (DWD), Europe.

Loading the latest forecast…

Questions about the sun in Sakai-nakajima

What is the best solar panel angle in Sakai-nakajima?
For a fixed array facing south, the best year-round tilt in Sakai-nakajima is 35°, worth about 1357 kWh per kWp a year. An off-grid system that has to get through October does better at about 38°.
What time is sunrise and sunset in Sakai-nakajima today?
On 25 October 2026 the sun rises at 05:58 and sets at 16:55 local time (UTC+9), giving 10 h 56 min of daylight. Solar noon is at 11:26.
How many peak sun hours does Sakai-nakajima get?
On a flat surface 3.8 hours a day averaged over the year, from 2.3 in December to 5.2 in May. Panels tilted at 70° receive 2.8 sun hours a day in July.
How high does the sun get in Sakai-nakajima?
At solar noon the sun stands 77.2° above the horizon on the June solstice and 30.3° on the December solstice.
Is Sakai-nakajima a good place for solar panels?
With 3.8 peak sun hours a day on flat ground, Sakai-nakajima ranks joint 664th of 1,216 places in Japan for sunshine. A 1 kWp array at the best angle (35°) makes about 1,357 kWh a year here, 6% more than the average place in Japan.

Places near Sakai-nakajima

All places in Japan

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Sun positions: NREL Solar Position Algorithm. Climate: NASA POWER monthly climatology (NASA Langley Research Center). Forecast: Deutscher Wetterdienst, ICON-EU (CC BY 4.0), processed. Places: GeoNames (CC BY 4.0). Time zones: IANA. Sources and licences.