Hawaii · United States · 21.34° N · 158.06° W
Solar position in Kapolei
Sun position, daylight and the best solar panel angle for Kapolei — computed for 21.34° N, 158.06° W, 22 m above sea level.
The sun right now
Sun in Kapolei today
Saturday, 24 October 2026 · local time UTC−10
| Event | Time | Direction / height |
|---|---|---|
| Astronomical dawn | 05:16 | sun 18° below horizon |
| Nautical dawn | 05:42 | 12° below |
| Civil dawn | 06:09 | 6° below |
| Sunrise | 06:31 | 102° ESE |
| Golden hour ends | 07:01 | sun 6° up |
| Solar noon | 12:16 | 56.7° high |
| Golden hour starts | 17:30 | sun 6° up |
| Sunset | 18:00 | 257° WSW |
| Civil dusk | 18:23 | 6° below |
| Nautical dusk | 18:49 | 12° below |
| Astronomical dusk | 19:15 | 18° below |
| Day length | 11 h 29 min | |
Sun path diagram for Kapolei
Where the sun stands in the sky: the centre is straight overhead, the outer ring is the horizon. Numbers mark local clock hours.
- June solstice
- Equinox
- December solstice
- Today
On the June solstice the sun reaches 87.9° at solar noon in Kapolei; on the December solstice only 45.2°. Sunrise swings from 64° ENE in June to 115° ESE in December — a 51° 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.
| Month | Sunrise | Solar noon | Sunset | Day length | Noon elevation |
|---|---|---|---|---|---|
| January | 07:12 | 12:43 | 18:15 | 11 h 03 min | 48.9° |
| February | 06:58 | 12:45 | 18:33 | 11 h 35 min | 58.4° |
| March | 06:35 | 12:39 | 18:43 | 12 h 09 min | 69.2° |
| April | 06:08 | 12:30 | 18:53 | 12 h 46 min | 80.8° |
| May | 05:51 | 12:28 | 19:06 | 13 h 14 min | 89.0° |
| June | 05:51 | 12:34 | 19:17 | 13 h 26 min | 87.9° |
| July | 06:01 | 12:38 | 19:15 | 13 h 14 min | 89.0° |
| August | 06:12 | 12:35 | 18:57 | 12 h 45 min | 80.5° |
| September | 06:20 | 12:25 | 18:29 | 12 h 08 min | 69.1° |
| October | 06:30 | 12:16 | 18:02 | 11 h 33 min | 57.7° |
| November | 06:47 | 12:18 | 17:49 | 11 h 02 min | 48.6° |
| December | 07:05 | 12:30 | 17:55 | 10 h 50 min | 45.2° |
A year of daylight in Kapolei
Each column is one day of 2026. Bright: sun above the horizon; soft: civil twilight; line: solar noon. Steps are daylight saving time changes.
Best solar panel angle in Kapolei
Fixed array facing south (azimuth 180°). Energy per kWp from NASA POWER monthly climate, including clouds, temperature and snow reflection.
19°collects the most energy over a year: 1767 kWh per kWp.
32°gives the most in the darkest month — the one an off-grid system is sized for.
- Yearly energy
- Worst-month energy
| Tilt | kWh/kWp per year | Share of best year | December kWh/kWp/day | Best ÷ worst month |
|---|---|---|---|---|
| 0° | 1687 | 95% | 3.20 | 1.8× |
| 15° | 1764 | 100% | 3.94 | 1.4× |
| 19° year-round best | 1767 | 100% | 4.09 | 1.3× |
| 21° = latitude | 1766 | 100% | 4.16 | 1.3× |
| 30° | 1737 | 98% | 4.43 | 1.2× |
| 32° off-grid best | 1725 | 98% | 4.47 | 1.1× |
| 45° | 1608 | 91% | 4.65 | 1.3× |
| 60° | 1389 | 79% | 4.58 | 1.9× |
| 70° | 1202 | 68% | 4.38 | 2.5× |
| 90° | 803 | 45% | 3.62 | 3.9× |
A fixed array in Kapolei produces the most over a year at 19°. The design month for an off-grid system is December: at 32° it makes 4.47 kWh per kWp a day, 9% more than at 19°, and costs 2% of the yearly total. Why steep panels win winter.
Off-grid solar in Kapolei at 70°
Daily energy of 1 kWp by month. Bars: panels at 70°. Line: panels at 19° (year-round best).
| Month | Sun hours, flat | Sun hours at 70° | kWh/kWp/day at 70° | at 19° | Mean temp. |
|---|---|---|---|---|---|
| January | 4.40 | 5.51 | 4.55 | 4.38 | 23.5 °C |
| February | 4.99 | 4.99 | 4.12 | 4.62 | 23.1 °C |
| March | 5.62 | 4.32 | 3.56 | 4.84 | 23.2 °C |
| April | 6.44 | 3.52 | 2.89 | 5.14 | 23.9 °C |
| May | 6.91 | 2.66 | 2.15 | 5.17 | 24.7 °C |
| June | 7.14 | 2.24 | 1.79 | 5.14 | 25.4 °C |
| July | 7.08 | 2.39 | 1.91 | 5.16 | 26.0 °C |
| August | 6.82 | 3.11 | 2.52 | 5.24 | 26.4 °C |
| September | 6.33 | 4.24 | 3.45 | 5.24 | 26.5 °C |
| October | 5.31 | 4.86 | 3.97 | 4.74 | 26.1 °C |
| November | 4.48 | 5.20 | 4.26 | 4.32 | 25.3 °C |
| December | 4.06 | 5.32 | 4.38 | 4.09 | 24.2 °C |
| Year | 5.80 avg | 4.02 avg | 1202 kWh | 1767 kWh |
Sizing example. To run a 1 kWh-per-day load through June on LiFePO4 batteries (charge controller, battery and inverter losses included) you need about 660 Wp of panels at 70°, versus 290 Wp at 19°. Here the lower tilt is the better winter choice — the sun stays high enough. Size your own system.
Row spacing in Kapolei
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.
2.8 mrow pitch at 70°
2.6 mrow pitch at 19°
How Kapolei compares in the United States
Against the other 3,120 places in the United States with climate data, for a fixed array at its best angle.
67thof 3,121 places in the United States for sunshine, shared: 5.80 peak sun hours a day on flat ground.
+17%solar energy a year compared with the average place in the United States: 1,767 against 1,515 kWh per kWp.
−1 h 40 mindaylight on the longest day, compared with New York City: 13 h 26 min against 15 h 06 min.
19°best year-round tilt here; across the United States it runs from 18° in Honolulu to 53° in Fairbanks.
Of the 3,121 places in the United States, Fortuna Foothills and 2 other places get the most sun (5.96 peak sun hours a day) and Juneau the least (2.38); Kapolei ranks joint 67th. In its darkest month, June, 1 kWp of off-grid panels at 70° makes 1.79 kWh a day here, against 2.55 kWh on average in the United States. The shortest day lasts 10 h 50 min, +1 h 35 min compared with New York City.
Solar forecast for Kapolei, next 48 hours
Expected output of 1 kWp at 70°, computed from the ICON-EU weather model of the Deutscher Wetterdienst (DWD), Europe.
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Questions about the sun in Kapolei
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Places near Kapolei
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A free, live card for Kapolei: where the sun is right now on today's path, a countdown to sunset or sunrise, the daylight change, the moon phase at night and the best panel angle.
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.