Will tonight's sky be worth it?
Tell us where you are and we read tonight's clouds, the moon's brightness and how dark your skies really are, then hand back one honest score for the hours after dark.
Treat the score as odds, not a promise. Clouds do what they like.
Add your location to see tonight's stargazing score.
What drives the score
Four things make or break a night under the stars. We weigh each one, then roll them into a single score from 0 to 10.
Clear sky
The biggest factor by far. We look at how cloudy it gets during tonight's dark hours, and even a hazy, half-clouded sky pulls the score down hard.
Site darkness
How much light pollution sits over your spot. A truly dark site shows thousands more stars than a glowing suburb, so where you stand matters almost as much as the weather.
Dark moon
A bright moon drowns out faint stars and the Milky Way. A new moon, or a moon that has already set, leaves the sky at its inkiest.
Dark window
How many genuinely dark hours you actually get after twilight fades. Short summer nights leave you very little time to work with.
Best national parks for stargazing
Every park below is a certified International Dark Sky Place. We rank them on a transparent score that blends site darkness with how often the sky stays clear at night.
| # | Park | State | Certified | Tier | Bortle | Clear nights | Score |
|---|
Best towns for stargazing trips
We ranked and compared towns in the UK and US by sky darkness, average cloud cover, elevation and access to recognised dark-sky areas.
| # | Town | Score | Avg cloud cover | Elevation | Nearby dark-sky area |
|---|
How the score works
No black box. For your location we read tonight's cloud cover, the moon's brightness, how dark your spot is and how many truly dark hours you get, then weigh them into a single number you can trust.
- Clouds carry the most weight, so a clear night beats everything else. We look at the forecast for the dark hours specifically, not whatever it happens to be doing right now, which is why a clear evening still scores well after sunset.
- Your darkness picker sets how much light pollution sits over your site. City skies wash out all but the brightest stars, a certified dark-sky park shows thousands more.
- The moon's brightness comes from its phase, worked out right in your browser with no lookup. A bright moon costs you points, and we ease off when the moon has already dropped below the horizon.
- The dark window is how long the sky stays genuinely dark after twilight. When you are online we pull tonight's exact twilight times, otherwise we estimate them from your latitude and the date. Near midsummer at far-north latitudes the sky may never fully darken, and we say so plainly rather than show a misleading number.
How parks are ranked
Each park's rank blends how dark the site is with how often its nights run clear. Both feed a single 0 to 100 score, so the order is fully reproducible.
- Certification year and tier are verified against DarkSky International's registry and the National Park Service.
- Where those bodies do not publish a number for a specific unit, the darkness rating and the share of clear nights are our own estimates, drawn from the park's tier, how remote it is and its regional climate. Those figures are marked (est.) in the table so you always know which numbers are measured and which are reasoned.
- Download the CSV to see every value, including which ones are estimated.
Sources. DarkSky International certified-places registry, NPS Night Skies program, Open-Meteo for the forecast, sunrise-sunset.org for twilight times, and Sky & Telescope for the Bortle dark-sky scale.
A forecast of a chaotic sky is odds, not a promise. Always check a current local forecast before you drive out.
How towns are ranked
To identify the best towns for stargazing trips, we compare US and UK towns separately using five factors: sky darkness, average cloud cover, access to recognised dark-sky areas, elevation and visitor practicality.
- Sky darkness carries the most weight. For the final published version, sky darkness should be measured with a licensed light-pollution source such as VIIRS Nighttime Lights, supported by recognised dark-sky status and surrounding landscape context.
- Average cloud cover is included because a very dark place is less useful for visitors if clear nights are rare. The ranking uses NASA POWER cloud amount for each town's coordinates.
- Dark-sky access rewards towns near certified DarkSky places, national parks, observatories, reserves or established public viewing areas.
- Elevation is treated as a smaller supporting factor because higher places can have clearer atmospheric conditions, but elevation alone does not guarantee good stargazing.
- US and UK towns are ranked separately because climate, settlement patterns and access to dark-sky areas differ too much for a fair combined table.
Additional sources for the towns ranking. VIIRS Nighttime Lights from the Earth Observation Group, NASA POWER cloud climatology, USGS Elevation Point Query Service, DarkSky International Places, and CPRE dark skies resources.