International Dark-Sky Week 2027
Monday 5 April to Sunday 11 April 2027 · dates set by the organiser each year
Join DarkSky International for a week of celebration, learning, and action.
Also on 5 April: Parkinson’s Awareness Week
What is International Dark Sky Week?
International Dark-Sky Week 2027 runs from Monday 5 April 2027 to Sunday 11 April 2027.
Join DarkSky International for a week of celebration, learning, and action. International Dark Sky Week is held each April, timed around the April new moon when the night sky is at its darkest, and forms a key part of Global Astronomy Month.
Created in 2003 by high-school student Jennifer Barlow, International Dark Sky Week has grown into a worldwide event. Because the dates are tied to the lunar cycle, the exact week shifts each year. In 2027 it is expected to run during the week of 5 to 11 April, around the April new moon. Please check the DarkSky International website for the confirmed 2027 dates.
In explaining why she started the week, Barlow said she wanted people to be able to see the wonder of the night sky without the effects of light pollution. The universe is our view into our past and our vision into the future, and she wanted to help preserve its wonder.
International Dark Sky Week draws attention to the problems associated with light pollution and promotes simple solutions available to mitigate it.
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Why Light Pollution Matters
The nighttime environment is a crucial natural resource for all life on Earth, but the glow of uncontrolled outdoor lighting has hidden the stars, radically changing the nighttime environment.
Before the advent of electric light in the 20th century, our ancestors experienced a night sky brimming with stars that inspired science, religion, philosophy, art and literature, including some of Shakespeare’s most famous sonnets.
The common heritage of a natural night sky is rapidly becoming unknown to the newest generations. In fact, millions of children across the globe will never see the Milky Way from their own homes.
We are only just beginning to understand the negative repercussions of losing this natural resource. A growing body of research suggests that the loss of the natural nighttime environment is causing serious harm to human health and the environment.
For nocturnal animals in particular, the introduction of artificial light at night could very well be the most devastating change humans have made to their environment. Light pollution also has deleterious effects on other organisms such as migrating birds, sea turtle hatchlings, and insects.
Humans are not immune to the negative effects of light in their nighttime spaces. Excessive exposure to artificial light at night, particularly blue light, has been linked to increased risks for obesity, depression, sleep disorders, diabetes and breast cancer.
Frequently asked questions
When is International Dark-Sky Week 2027?
International Dark-Sky Week 2027 runs from 5 April 2027 to 11 April 2027. It is held dates set by the organiser each year.
What is International Dark-Sky Week 2027?
Join DarkSky International for a week of celebration, learning, and action.
More awareness days in April
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22 Apr22 AprThursdayEducation & YouthUK, US, Australia and worldwideInternational Mother Earth Day 2027
23 Apr23 AprFridayArts & CultureInternationalWorld Book Night 2027
25 Apr25 AprSundayCommunityInternationalThe London Marathon 2027
1–30 AprMonth1 Apr to 30 AprMonthAnimals & WildlifeInternationalNational Pet Month 2027
1–30 AprMonth1 Apr to 30 AprMonthHealth & WellbeingInternationalStress Awareness Month 2027
1 Apr1 AprThursdayFun & QuirkyUK, US, Australia and worldwideApril Fools’ Day 2027
5–11 AprWeek5 Apr to 11 AprWeekHealth & WellbeingUKParkinson’s Awareness Week 2027