The Black Rain of Slains

Aberdeenshire's Forgotten Weather Mystery

By the cliffs of Slains Castle, where sea mist drifts through ruined windows and the North Sea pounds against the rocks below, local legend often centres on ghosts, smugglers and Dracula. Yet one of the strangest stories associated with this stretch of the Aberdeenshire coast has nothing to do with folklore. It concerns an extraordinary weather event that left nineteenth-century residents looking skyward in disbelief as black rain fell from the heavens.

Regular visitors to Cruden Bay Life will know that we love to tell our stories through song as well as words. We’ve posted an accompanying audio track alongside this story, and we hope you’ll enjoy listening to it as you read.

The Black Rain Of Slains

by Cruden Bay Life

A Strange Fall from the Sky

The coastline between Cruden Bay and Slains has always been a place where nature commands attention. Towering sandstone cliffs, violent winter storms and rolling sea fog have shaped both the landscape and the lives of those who lived there. Fishermen accepted the sea’s unpredictability as part of daily life, but few could have anticipated the remarkable phenomenon reported during the early 1860s.

Local records describe an unusual event in 1862–63, when rain falling over the Slains estate appeared dark—almost black. Unlike ordinary rain, this shower reportedly left a noticeable deposit, prompting widespread discussion throughout the district.

Adding further intrigue, pieces of pumice stone were discovered washed ashore along the nearby coastline during roughly the same period. Pumice, a volcanic rock so porous it can float for months or even years, was not something local people expected to find on the beaches of northeast Scotland.

Taken separately, the two occurrences might have been dismissed as curiosities. Together, they presented an irresistible mystery.

A Scientific Puzzle

The reports attracted the interest of one of Britain’s leading meteorological figures: Admiral Robert FitzRoy.

Today FitzRoy is remembered not only as the captain of HMS Beagle during Charles Darwin’s famous voyage, but also as the founder of Britain’s organised weather forecasting service. His lifelong fascination with atmospheric conditions led him to investigate numerous unusual weather events, including the strange reports from Slains.

Although FitzRoy examined accounts of the phenomenon, no firm conclusion emerged. Nineteenth-century science simply lacked many of the analytical tools available today. Without chemical analysis of collected rainwater or microscopic examination of the particles suspended within it, investigators could do little more than compare observations and propose theories.

The Volcanic Theory

Among the explanations considered then—and still regarded as the most convincing today—is that the rain carried volcanic ash.

The North Atlantic is home to some of the world’s most active volcanoes, particularly those of Iceland. Modern experience has shown just how far volcanic ash can travel. During the eruption of Eyjafjallajökull in 2010, ash clouds spread across much of northern Europe, grounding aircraft for days and demonstrating the enormous reach of atmospheric circulation.

Although nineteenth-century observers lacked satellites or modern weather models, they recognised that strong upper-air winds could transport fine particles over considerable distances.

The pumice discovered along the Slains coast provides an intriguing piece of supporting evidence. Because pumice floats, it can drift across oceans on prevailing currents before eventually washing ashore hundreds or even thousands of miles from the eruption that created it.

If volcanic pumice reached Aberdeenshire’s beaches, could volcanic ash have reached its skies?

It remains an attractive hypothesis.

Other Explanations

Not everyone accepted a volcanic origin for the Black Rain. Although the presence of floating pumice seemed to support that theory, alternative explanations were also considered, both at the time and by later researchers.

Industrial Britain was producing unprecedented quantities of smoke and soot as factories, foundries and coal-fired steam engines transformed the landscape. Some suggested that dark particles from distant industrial centres could have been carried northwards by prevailing winds before being washed from the atmosphere by rainfall.

Others pointed to extensive peat or forest fires elsewhere in Britain or Scandinavia. Large-scale fires can inject enormous quantities of smoke and fine ash into the upper atmosphere, where they may travel hundreds of miles before eventually falling back to Earth with rain.

Windborne dust offered another possibility. Even today, Saharan dust occasionally reaches Scotland, leaving a fine reddish coating on cars and windows after rainfall. Similar long-distance transport of darker mineral dust was considered plausible.

Yet none of these explanations convincingly accounted for the simultaneous appearance of floating pumice along the nearby coastline, leaving the volcanic theory as perhaps the most compelling, though still unproven, explanation.

Life at Slains in the 1860s

To appreciate how remarkable the event seemed, it is worth imagining daily life in the parish during the 1860s.

The imposing New Slains Castle dominated the landscape from its clifftop position, while tenant farmers worked the surrounding fields and fishing families launched their boats from nearby harbours. Communication was improving thanks to expanding railways elsewhere in Scotland, but news still travelled largely by newspapers and word of mouth.

An unusual shower would quickly become the talk of every village.

People would naturally have examined roofs, walls and clothing for signs of staining. Farmers might have wondered whether crops had been damaged. Fishermen, whose livelihoods depended on reading the weather, would almost certainly have discussed the phenomenon in detail.

Although no reports suggest panic, the event clearly made enough impression to be recorded in local histories and later gazetteers.

The Mystery Endures

Unfortunately, many nineteenth-century observations survive only as brief summaries. References in local histories note the occurrence of “black rain” and the discovery of pumice but provide little scientific detail.

No preserved samples of the rainfall are known to exist.
No laboratory analysis survives.
No definitive meteorological explanation has ever been accepted.

Consequently, historians are left piecing together fragments from contemporary reports, local tradition and scientific knowledge developed long after the event itself.

A Modern Perspective

If an identical event occurred today, scientists would begin investigating almost immediately. Environmental specialists would collect rainwater samples from across the affected area, examining them for microscopic fragments of volcanic glass, industrial pollutants, soot particles, pollen, marine aerosols and windborne mineral dust. Each of these leaves a distinctive chemical signature, allowing researchers to determine not only what had fallen from the sky, but often where it had originated.

At the same time, meteorologists would analyse satellite imagery, weather radar and atmospheric data to trace the movement of air masses over the North Atlantic. Sophisticated computer models could reconstruct wind patterns stretching back days or even weeks, revealing whether the particles had arrived from an Icelandic volcanic eruption, smoke from distant wildfires, industrial emissions or even desert dust carried thousands of miles on high-altitude winds. Modern atmospheric science has become remarkably skilled at tracking the global movement of tiny airborne particles.

The pumice discovered along the Slains coastline would also undergo detailed examination. Geologists could compare its mineral composition with known volcanic sources, while oceanographers would use computer models to estimate how long it had drifted at sea before washing ashore. Together, these investigations would build a comprehensive picture of the event, enabling scientists to determine whether the black rain and the floating pumice were connected or merely an extraordinary coincidence.

Within hours—or perhaps a few days—the mystery might well be solved.

In the 1860s, however, such certainty was beyond reach. Weather forecasting was still in its infancy, laboratory techniques were limited and investigators relied largely upon eyewitness accounts and careful observation. Although respected figures such as Admiral Robert FitzRoy took an interest in the reports, they lacked the scientific tools needed to reach a definitive conclusion.

Instead, the people of Slains were left with an unexplained phenomenon that challenged contemporary understanding. More than 160 years later, that unanswered question remains one of the most intriguing chapters in Aberdeenshire’s natural history, reminding us that even familiar landscapes can still hold remarkable mysteries.

More Than Local Folklore

The Black Rain has never achieved the fame of Scotland’s great natural disasters or famous storms, yet it occupies an unusual place in Aberdeenshire’s history.

Unlike many local legends, this story rests upon documented reports rather than oral tradition alone. Contemporary writers considered it sufficiently remarkable to record, and respected scientific figures regarded it as worthy of investigation.

That combination gives the episode an unusual credibility, even if its precise cause remains elusive.

Overshadowed by Dracula

Ironically, the mystery of the Black Rain has largely been eclipsed by another story forever associated with Slains Castle.

When Bram Stoker spent time in nearby Cruden Bay during the 1890s, the dramatic silhouette of the castle, perched high above the North Sea on sheer cliffs, is widely believed to have helped inspire the fictional home of Count Dracula. Whether or not Slains was the sole inspiration, its imposing towers, ruined grandeur and isolated coastal setting undoubtedly possess the Gothic atmosphere that permeates Stoker’s famous novel. Today, visitors are far more likely to hear tales of vampires, secret passages and literary connections than of Victorian meteorology.

Yet the Black Rain possesses an eerie quality all its own. Unlike the legends surrounding Dracula, this was an event witnessed by ordinary people and recorded in contemporary accounts. Imagine standing on the windswept cliffs as dark clouds gathered overhead, only to see rain falling that left black deposits on the ground. Days later, pieces of floating volcanic stone washed ashore, adding another layer to an already baffling occurrence.

For those who experienced it, the combination of black rain and strange stones must have seemed almost supernatural. Even today, the mystery retains a haunting quality that sits comfortably alongside the Gothic reputation of Slains Castle itself.

An Unanswered Question

More than 160 years have passed since the Black Rain was reported over the Slains estate.

Was it volcanic ash drifting from Iceland?

Industrial soot carried by unusual atmospheric conditions?

A rare combination of unrelated natural events?

The evidence is too limited to provide a final answer.

What remains is a fascinating glimpse into a time when even the weather could become a mystery, and when the people of a small corner of Aberdeenshire found themselves at the centre of a phenomenon that continues to intrigue historians, meteorologists and local researchers alike.

Sometimes the most remarkable stories are not those of castles or ghosts, but of the day the rain itself turned black.

Listen To The Podcast

The Story Lives On

Although the Black Rain of Slains remains a little-known episode in Aberdeenshire’s history, it has found a new audience in recent years through podcasts and online discussions that celebrate Britain’s more curious historical mysteries.

One notable example is an episode of the Loremen Podcast, in which hosts Alasdair Beckett-King and James Shakeshaft revisit the Black Rain from a thoroughly modern perspective. Rather than attempting to solve the mystery, they delight in exploring its more unusual aspects, examining the various theories that have surrounded the event—from volcanic ash and industrial pollution to some decidedly more imaginative explanations.

Their approach is intentionally light-hearted. Where nineteenth-century observers and later historians sought scientific answers, the hosts embrace the enduring mystery, mixing genuine historical research with humour, wit and the occasional absurd tangent. It is a reminder that stories like the Black Rain can be both historically significant and enormously entertaining.

The episode also highlights how enduring local mysteries continue to capture the public imagination. More than 160 years after residents around Slains looked skywards in astonishment, the event still prompts discussion, speculation and fresh interpretations. Modern audiences may smile at some of the more fanciful theories, but the central question remains exactly as it was in the 1860s: what really caused the rain to fall black over the Aberdeenshire coast?

In many ways, that unanswered question is what keeps the story alive. Whether viewed through the careful lens of historical research or the good-humoured curiosity of modern storytellers, the Black Rain of Slains continues to occupy its own distinctive place among Scotland’s most intriguing unsolved mysteries.