Home / Editor's Pick /

Weather explained: What are noctilucent clouds?

15:00
28 August 2022

Weather explained
What are noctilucent clouds?

Noctilucent cloudsNoctilucent clouds shine in the night sky over Tynemouth Priory and Castle in June 2022. - © picture alliance

Bright, shimmering noctilucent clouds illuminate the skies each year with a season spanning from May to August, here's how.

Known as noctilucent clouds, these rare clouds form around 50 miles above Earth’s surface in the mesosphere during summer months.

The unusual display of blue and silver ribbon clouds can keep the evening sky bright hours after the sun has set.

It is not known for sure how these clouds form, although we know that they shine thanks to the sun’s light illuminating ice crystals from beyond the horizon.

These crystals reflect the light onto dust particles in the mesosphere, where temperatures reach -134C.

Best viewed when the sun has just set below the horizon, 90 minutes after sunset, the clouds are most likely to appear between June and August for those of us in the Northern Hemisphere although their full season runs from May to August.

If you spot any bright shining clouds at night in the coming months, we would love to see them!

Snap a picture and submit by tapping the image icon in our app or use the dedicated picture uploader.

Weather & Radar editorial team
More on the topic
pinecones
Tuesday 23 September 2025

Did you know?

How pine cones aid the weather forecast
The weather map shows a cold front stretching from France to Scandinavia, with lower temperatures in the west. Eastern and southern Europe will remain very hot, with temperatures reaching up to 30 degrees.
Friday 19 September 2025

Weekend weather

Large temperature contrasts in Europe
WindRadar shows wind speeds exceeding 150 kilometres per hour on the coast of China
Wednesday 24 September 2025

Damage and fatalities

Typhoon RAGASA rages in Southeast Asia
All weather news
This might also interest you
Friday 15 August 2025

Breakfast brief

Split with cooler north, hot south
Friday 22 August 2025

Breakfast brief

Sunny start for some, overcast later
Sunday 24 August 2025

Your weather - Your shots

Mammatus clouds widely spotted
All articles
Weather & Radar

www.weatherandradar.ie

facebooktwitteryouTubeContact uslinkList
Privacy Policy | Legal info | Accessibility statement