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 | 39% |
| February | 24 | February 10 to 16 | 1.5 | 36% |
| March | 45 | March 9 to 15 | 3.0 | 39% |
| April | 57 | April 6 to 12 | 4.5 | 43% |
| May | 41 | May 3 to 9 | 5.9 | 59% |
| June | 42 | June 1 to 7 | 7.3 | 58% |
| July | 50 | July 1 to 7 | 6.9 | 50% |
| August | 52 | August 1 to 7 | 4.7 | 48% |
| September | 34 | September 21 to 27 | 2.9 | 53% |
| October | 17 | October 18 to 24 | 1.4 | 52% |
| November | 0 | No moon-free core hours | 0 | 49% |
| December | 0 | Core not visible | 0 | 42% |
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
- April: April 11 is the best night. The core is above 10 degrees and the moon is down from 12:18 am to 4:48 am, with the moon 30% lit that night.
- July: July 1 is the best night. The core is above 10 degrees and the moon is down from 8:28 pm to 3:48 am, with the moon 6% lit that night.
- August: August 1 is the best night. The core is above 10 degrees and the moon is down from 8:18 pm to 1:48 am, with the moon 0% lit that night.
Clock times are Atlantic 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 Virgin Islands National Park
Virgin Islands National Park covers about 60 percent of St. John in the US Virgin Islands. Trunk Bay and other beaches have clear water and easy snorkeling over coral and seagrass. Inland, hiking trails pass old sugar plantation ruins such as Annaberg.
Laurance Rockefeller bought up land on St. John and gave it to the government, and the park was established in 1956. The sugar plantations that once covered the island relied on enslaved labor, and a major revolt took place on St. John in 1733.
Virgin Islands National Park is a national park in the US Virgin Islands. The National Park Service places its center at 18.34 degrees north and 64.74 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 Virgin Islands National Park compares
Its best monthly core score of 57 ranks 26 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 Virgin Islands National Park runs from 36% in February to 59% in May.
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 Virgin Islands 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 Virgin Islands National Park?
April, July and August are the best months. The best week of 2027 is April 6 to 12.
Can you see the Milky Way at Virgin Islands 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 Virgin Islands National Park?
The Park Service's sky model covers only the contiguous United States and has no value at the reference point used for Virgin Islands National Park, which is outside its coverage or over water, so no sky darkness figure is shown here.
Does the moon matter at Virgin Islands National Park?
Yes. A bright moon hides the Milky Way. The best night in April is April 11, when the moon is 30% lit and the core is above 10 degrees from 12:18 am to 4:48 am.
