The core clears 10 degrees during full darkness on most nights from February to October. In January, November and December it's out of reach, either too close to the Sun or too low in the dark.
Core score by month
| Month | Core score | Best week | Moon-free core hours a night | Average cloud |
|---|---|---|---|---|
| January | 0 | No moon-free core hours | 0 | 42% |
| February | 19 | February 10 to 16 | 1.4 | 47% |
| March | 34 | March 9 to 15 | 2.9 | 53% |
| April | 52 | April 5 to 11 | 4.3 | 48% |
| May | 59 | May 3 to 9 | 5.6 | 41% |
| June | 58 | June 1 to 7 | 7.0 | 42% |
| July | 60 | July 1 to 7 | 6.7 | 40% |
| August | 64 | August 1 to 7 | 4.5 | 36% |
| September | 42 | September 21 to 27 | 2.8 | 39% |
| October | 18 | October 18 to 24 | 1.3 | 46% |
| November | 0 | No moon-free core hours | 0 | 48% |
| December | 0 | Core not visible | 0 | 46% |
Times are for the best seven nights in each month. Moon-free means the moon is below the horizon. The core counts as visible above 10 degrees in full darkness, when the Sun is more than 18 degrees below the horizon.
The best nights in 2027
- May: May 8 is the best night. The core is above 10 degrees and the moon is down from 10:44 pm to 4:24 am, with the moon 12% lit that night.
- July: July 1 is the best night. The core is above 10 degrees and the moon is down from 8:34 pm to 3:44 am, with the moon 4% lit that night.
- August: August 1 is the best night. The core is above 10 degrees and the moon is down from 8:24 pm to 1:44 am, with the moon 0% lit that night.
Clock times are Hawaii time, which doesn't observe daylight saving. The best nights fall around the new moon, so the dates shift by about 11 days each year.
About Haleakalā National Park
Haleakala is the huge volcano that makes up most of East Maui. At the summit, 10,023 feet up, a vast crater-like valley about seven and a half miles long opens beneath you. The park also reaches down to the sea, and its Kipahulu district has pools and waterfalls fed by rainforest.
In Hawaiian tradition the name means House of the Sun, from a tale of the demigod Maui lassoing the sun. The area was part of Hawaii National Park from 1916, then became its own park in 1961.
Haleakalā National Park is a national park in Hawaii. The National Park Service places its center at 20.71 degrees north and 156.16 degrees west, and the sky calculations on this page use that point. Visitor information, fees and alerts are on the park's own page. National Park Service (opens in a new tab).
How Haleakalā National Park compares
Its best monthly core score of 64 ranks 22 of 54 national park units that can see the core. The highest is Lassen Volcanic National Park at 86, and the lowest is Voyageurs National Park at 13. Cloud at Haleakalā National Park runs from 36% in August to 53% in March.
The score ranks months and parks. It isn't a forecast for any night, and it leaves out local weather, smoke and light from nearby towns. How the core score works.
How dark is the sky?
The Park Service's sky model covers only the contiguous United States and has no value at the reference point used for Haleakalā National Park, which is outside its coverage or over water, so no sky darkness figure is shown here.
Questions people ask
When is the best time to see the Milky Way at Haleakalā National Park?
May, July and August are the best months. The best week of 2027 is August 1 to 7.
Can you see the Milky Way at Haleakalā National Park all year?
The core clears 10 degrees during full darkness on most nights from February to October. In January, November and December it's out of reach, either too close to the Sun or too low in the dark.
How dark is the sky at Haleakalā National Park?
The Park Service's sky model covers only the contiguous United States and has no value at the reference point used for Haleakalā National Park, which is outside its coverage or over water, so no sky darkness figure is shown here.
Does the moon matter at Haleakalā National Park?
Yes. A bright moon hides the Milky Way. The best night in August is August 1, when the moon is 0% lit and the core is above 10 degrees from 8:24 pm to 1:44 am.
