A pileus formation is a smooth cap of cloud that appears on top of a large Cumulus congestus that is building rapidly upwards in the sky…

This month’s image, which rightfully belongs in our ‘clouds that look like things’ section, had residents in Exeter, UK, gazing up in disbelief as what looked like a flying carpet passed overhead…

Lightning heats the air around it to a temperature equivalent to four times that of the surface of the Sun. It does so within just a few millionths of a second…

Still water can act as a fantastic mirror on the sky, giving you two cloudscapes for the price of one…

Sunrise is often a tranquil and peaceful scene, perhaps with some wisps of Cirrus cloud or a patch of fair-weather Altocumulus – even, heaven forbid, clear blue skies…

We think of cloudspotting as a predominantly daytime activity. But, as the Cloud of the Month for April shows, it needn’t be when there is a full moon…

This Month’s formation boldly goes where no cloud has gone before. Resembling the Starship Enterprise, it is in fact a dramatic example of a Cumulonimbus incus…

It is a Bird? Is it a Plane? No, it’s an Altocumulus lenticularis – in the shape of a bird. Or a plane…

Is this some strange luminescent green form of cloud? Well, yes and no…

The cloud of the month for December is the Altocumulus asperatus undulatus. It is the cloud that aspires to be recognised…

November’s Cloud of the Month features the cloud feature known as a tuba. This finger of cloud forms within the rotating air below a Cumulonimbus storm cloud…

Clouds come in all shapes and sizes, but Cloud of the Month for October exhibits gigantic proportions…

Cloud of the Month for September is Craig Cooper’s rainbow over Stanton Lacy, Shropshire, UK…

Cloud of the Month for August is the elusive night-shining, Noctilucent cloud…

This month’s image, by Doug Short, shows a mix of cloud types over Anchorage, Alaska…

This month’s choice is taken from one of our favourite parts of the Cloud Appreciation Society photography gallery…

This dramatic lenticularis cloud formation at sunset over Grangemouth, Scotland, looks like a Sci-Fi poster…

The Cloud of the Month for April was photographed over Brazil by Pilot Ron Engels from the flight deck…

This month’s cloud, spotted by Marc Puigdomenech over Tortosa, Catalonia, Spain, is a huge Altocumulus cloud of the species known as ‘lenticularis’…

The Cloud of the Month for February is Basil Stathoulis’s photograph of dramatic thunderstorms lined up across the vast expanse of Botswana’s Okavango Delta…

Very rare arcs and halos appeared at the end of October 2012 as the sunlight shone through the ice crystals of Cirrostratus clouds…

When Cirrus clouds are arranged like the backbone of a fish, they are given the name ‘vertebratus’…

Lenticularis clouds dominate the cloudscape over the Torres del Paine mountains, Chile…

Lightning can take many different paths as the enormous electrical charges that build up with in Cumulonimbus storm clouds suddenly redistribute themselves…

The cloud of the month for September was spotted by Sebastian Luciano Ferla over Monte Cofano in Sicily, Italy…

The Cloud of the Month for August is a display of mamma clouds photographed by Kamila Mazurkiewicz over Puławy, Poland…

A Picture Postcard from The Netherlands

Clouds appearing simultaneously at several different levels of our atmosphere is a common sight, one that is sometimes described as a ‘mixed sky’. The tranquil concoction of clouds chosen as July’s Cloud of the Month was spotted over the hamlet of Huls in the south of The Netherlands.

© Photograph Math Gossens.

The Northern Lights

This month’s image is the notoriously elusive Aurora Borealis, also described as The Northern Lights. Photographer, Norman Shulman, was very fortunate in spotting this enchanting display over Myvatn, in N.E. Iceland. The natural light show in the sky occurs at its most spectacular over Arctic and Antarctic regions and is caused by the collision of energetic charged particles with atoms in the earth’s high altitude atmosphere. The particles originate from solar storms are carried on solar winds before being lured to our atmosphere by the Earth’s magnetic field. And in the foreground? None other than our beloved Altocumulus lenticularis clouds, of course.

© Photograph Norman Shulman.

The Sun Sets Over Bali

This month’s image is from the island of Bali in Indonesia. Unwind beneath the golden Altocumulus clouds. Bathe in the warmth of the sunset colours. On the horizon, the towering Cumulus are darkening in the shadow of the Earth, as the waves lap at your feet on the rippled sand of the water’s edge.

© Photograph Willem Tesselaar.

Iridescence over Independence

This month’s cloud formation is a display of cloud iridescence. This colourful optical effect is caused by sunlight being diffracted as it passes around the cloud particles, and is seen mostly often when a cloud is forming or dissipating, which means its water droplets are all of a similar size. The beautiful and eery example shown here is in an Altocumulus cloud spotted by Andrew Kirk over Independence, California, US.

© Photograph Andrew Kirk.

Florida Fog

This month’s dramatic image of stratus cloud pouring over condominiums, was observed initially by helicopter pilot Mike Schaeffer. He was completing a sightseeing tour when he spotted this strange weather phenomenon along Panama City Beach, Florida. On landing, he told the helicopter company owner, J.R. Hott, about the cloud formation and they both went up for a better view. They moved quickly, knowing that this beautiful effect could only occur in very specific weather conditions.

The fog formation has since been described in the media as a “cloud tsunami” but J.R. disagrees with this name. “The term tsunami implies a natural disaster,” he explained, “but this cloud effect, though it can form quickly, moves in a gradual manner. It only occurs in the presence of a gentle breeze.”

Photograph © JR Hott.

Upside Down Lightning Over Penang, Malaysia.

This month’s image shows a dramatically different perspective on lightning, which here appears to be travelling upwards within the Cumulonimbus storm cloud. This type of lightning is sometimes described as spider or anvil crawler lightning, and was spotted over Penang, Malaysia, by Mike Sharp. He describes the area as “most exciting weatherwise”. How could we disagree?

Photograph © Mike Sharp.

Iridescent Lenticular clouds over Mount Rainier

This month’s image shows the beautiful effect that can result from the sunlight shining through thin parts of a cloud where the tiny droplets or ice crystals all have similar sizes. The sunlight can be ‘diffracted’ as it passes around the miniscule particles. The result is that it is split into different wavelengths, which appear as the colours of the rainbow. This optical effect is called iridescence or irisation and tends to appear at the fringes of clouds. This fantastic example, captured by Ryan Verwest, shows iridescence in lenticular clouds, and was spotted over Mount Rainier, Washington, US.
Photograph © Ryan Verwest.

Classic Cirrus

This month’s image was spotted over South Carolina, US.
© Photograph Betty Owen.

A sunset over Mount Rainier

Mount Rainier’s shadow being cast onto the clouds above makes it look like it is erupting. The dramatic light effect was spotted over Washington, US.
Photograph © Nick Lippert.

Cap clouds over the volcano brothers

The cloud-capped twin volcano brothers, Nevados de Payachata. The one with the crater at the top is the Parinacota volcano. The other is the Pomerape volcano. Location Bolivia, near the border of Chile.
Photograph © Alexandre Militao.

A Singer Serenading the Sunset

Well, at least, it looks like one to us. Spotted over Valona, Albania.
Photograph © Maurizio Barbieri.

Noctilucents over Edmonton

This month’s fantastic display of noctilucent clouds was spotted over Edmonton, Alberta, Canada.
Photograph © Hayley Dunning.

A Light Show over Bangkok

This month’s electric display was spotted over Bangkok, Thailand.
Photograph © Sitthivet Santikarn.

Minnesota Mammatus

The mammatus clouds that are this month’s pinups appeared below a storm rolling in at sunset over Lino Lakes, Minnesota, US.
Photograph © Jackie Zeleznikar.