The nights this month with the most moonless dark, ranked by the Moon’s brightness and hours up, to shortlist nights for deep-sky imaging and meteor watching.
Frequently asked questions
How are the nights ranked?
By the Moon over the whole astronomically dark part of each night (the Sun 18° or more below the horizon): how much of its disc is lit, times the share of those dark hours it is above the horizon. This is the Tonight score’s own Moon rule. A bright Moon that sets soon after dusk costs a night little; a fat Moon up from dusk to dawn costs it the most. Each row gives the moonless dark hours. Each night is named by the date it begins. The list shows the eight darkest nights.
Which calendar and time zone does it use?
Your location’s. The month is the current month where your location pin is, and the dark hours, moonrise and moonset are computed for that place. The Moon’s phase is the same from everywhere on Earth, but when it rises and sets is not.
Is weather included?
No. Pair this list with Stargazing Weather and Tonight Score before you drive.