How to be an Autumn swimmer

Lance Sagar offers an enthusiast's guide to swimming in the autumn months

Lance Sagar

All the leaves are brown, and the sky is grey… While summer and winter swimming steal much of the limelight, Lance Sagar makes the case for autumn swimming: a singular time of rapidly changing weather and light, the magic of leaf fall on water, and immersion in great migrations above and below the waterline.

The long and carefree swims of summer, enveloped by lush green forest and with a playful lack of concern for direction or duration, are over and winter is on the way, bringing with it pitch-black mornings and icy dips, woolly bobble hats and shivering away the afterdrop over a flask of hot coffee. For many this has been a long time coming. For others though, we’d be happy to see it take a little longer. Thankfully though, summer doesn’t meekly decline into winter. In the natural world at least, autumn provides summer’s glorious crescendo – ending with an explosion of golden leaves, golden light and peerless natural spectacle.

Blink and you may miss it: the autumn that we’ll see as outdoor swimmers and nature lovers is one marked out less by dates and more by natural phenomena. Whether by virtue of the unpredictable nature of the natural transitions or the disruptive weather that so often accompanies them, this is a short season indeed, but it is one that it would be a great shame to miss. So this guide to being an autumn swimmer is in part a celebration of this tiny season of ours. It’s more than a mere bridge to winter; it’s the high-water mark of nature’s year and a fitting sendoff for our summer. Perhaps this also forms an attempt to re-insert this season into the outdoor swimming discourse, back to its place among its better-loved siblings: summer swimming and cold water stoicism. 

Where to go

The complete autumn swimming experience requires immersion in nature and for this you need to go out into the wild places. First among the natural swimming locations in which to enjoy the season must surely be the forests. Lakes and reservoirs can offer a great forest backdrop, a large-scale diorama of autumn colours illuminated by the softer autumnal sunlight. It’s an environment of big skies and enough birdlife to fill them. For me though, nothing compares to the feeling of swimming through the forest, being enclosed by the trees and on rare occasions, showered by the falling leaves. For the full forest bathing experience, look to the forest rivers. Forest rivers tend to be narrower and shallower than other waterways but it is this that makes them worth the extra effort – the forest envelopes you and the canopy covers the sky. In order to have a good swim though, we need to find a deep enough section. Pools below waterfalls can provide the depth and setting for a dramatic forest dip and longer deep sections may be formed above a weir or natural obstruction. Sometimes it’s simply a matter of the topography of the riverbed, where a deep pool is formed in a section of an otherwise shallow river. If nothing else, finding such a spot is a good excuse for an autumnal riverside walk.

One such autumn swim took place in front of a waterfall (pictured right, the swim spot further into the scene) in a forest glen, where the trees spread out above our heads and the leaves were a deep yellow, primed to fall. A strong gust of wind blew, the leaves took flight and for a moment the scene resembled a snow globe. A spontaneous cheer emanated from swimmers and photographers alike. Finding a swimming spot in an open, tree-free space has its own attractions. Though lacking in leaves, wide-open spaces can give back in wildlife, particularly around this time of great migration (see below for more on this). Set in the lower evening and morning sun, the lakes, reservoirs and ponds also shine.

Lance Sagar

The Physical Environment

Leaf swimming: Perhaps the first thing that comes to mind when thinking of swimming in autumn is the fallen leaves. There is something of a tradeoff here though – swim against a backdrop of thick golden forest or swim through the freshly fallen leaves? There is a slim, brilliant window where you can just about do both together, but it doesn’t last long. Expect to see the most significant fall later in autumn after heavy rain or strong winds. Don’t be surprised to see more foam on the water too. Unless derived from pollution, this should not always be a cause for concern. As leaves and other organic matter break down in the water, they produce organic surfactants, breaking the surface tension of the water and allowing air to enter, creating the surface foam. Expect to see it below waterfalls or at the water’s edge wherever waves break. The foam inscribes the flow of the river on its surface, creating complex patterns which are particularly beautiful in eddy pools. If you’re confident of the source, they’re great to swim through at this time of year.

Colder waters: Bodies of water tend to retain the summer heat in proportion to their depth, with the sea staying warmer for longer and rivers becoming icy-cold all too quickly. Still, whilst the initial bite of the cold water may sting, these are no mid-winter temperatures. Those of us left underwhelmed by dips measured in single digit minutes can see this as the last chance for a longer swim, and maybe even the last time we’ll dare to place our faces in the water. Our foreheads will be thankful for any remnant heat.

Changing weather: Autumn is a season of changing weather, often across the course of a single day. There’s something particularly energising about swimming in the rain, more so when there is a chance that the sun will break through the clouds and radically alter the experience. It brings rainbows and rain to waters which, while cold, still carry enough warmth to help us greet the changing weather with excitement. The rains will swell the rivers (and hopefully our alarmingly low lakes and reservoirs) too. This does necessitate a bit more planning around when to swim, particularly around strong currents and with consideration for what the flow could be bringing downstream. The weather itself seems to determine the length of the season as experienced by the swimmer. Strong winds can dislodge the leaves from the trees early, heavy rains can make rivers unsafe. It’s hard to plan for but then this isn’t a season that you can predict too far in advance. Every autumn is unique.

Shorter days, glorious light: Autumn is the perfect season to experience the light and the dark together. Sunrise swims are possible without having to set a painfully early alarm. The lower sun means that on a sunny day, late afternoons are flooded with golden light. Night swimming is also possible at more socially acceptable times, and more desirable than in winter when the sensation of being in darkness may be somewhat less of a treat.

Autumn is a season of changing weather, often across the course of a single day. There’s something particularly energising about swimming in the rain, more so when there is a chance that the sun will break through the clouds and radically alter the experience.

Natural companions

To swim in autumn is to immerse ourselves in the great arrival. Spring and autumn are of course known as those transitional seasons where migratory species make their journeys. From the point of view of the UK and Western Europe though, it is autumn that brings the greatest spectacle. One reason for this is the dynamics of what is often referred to as the East Atlantic Flyway – many of our bird species spend their summers in the north and return here for a (comparatively) mild winter. From a UK perspective in particular, the water is where so much of it happens. Naturally lacking in any great land migrations, the migratory species either fly or swim here and the birds that winter in the UK are often water-based. To swim in the autumn then is to share the space with these arrivals, and as we watch them we know that we could be seeing their arrival in real time.

Skeins of geese are a regular sight for the lake and reservoir swimmers in the autumn, flying in their distinctive v-shape and communicating with honks and rolls. You may well hear the swans before you see them too, the movement of their wings creating a drumbeat as they fly low over the water. Many of these large migratory birds have spent the summer in the arctic circle or Iceland and will loudly announce their return. The sights aren’t limited to large birds migrating from colder climates though, starling numbers are boosted as migrants return from Europe and the Middle East, leading to stunning murmurations over lakes and wildlife reserves in the late autumn. Keep an eye out for the goosander too – they won’t get as close to you in the water but many males return from Norway in late autumn, with more local populations moving towards lakes and reservoirs from their upland river summer homes.

The migration also happens below the waterline, and no migration is more spectacular than the salmon run. Returning in the autumn to spawn at the site of their birth, the salmon initially congregate in lowland waters. As the rain swells the rivers, the salmon make their journeys upstream, famously jumping to clear obstructive waterfalls. I am not best placed to explain any effect that a swimmer may have on a passing salmon but I might like to assume they’d at least be pleased we’re not fly-fishing for them. Whilst low on the list of barriers they face, it must be best for swimmers to stay out of the specific areas that they’re jumping from (and it is vital not to disturb the locations where they spawn). However, I can attest that a morning of swimming amongst the fallen leaves followed by an afternoon of watching the salmon (who must have passed me in the water) jump upstream of the swim location is a great way of filling up on nature.

It isn’t just the migratory species that shine in autumn. Swimmers amongst the reed beds on a foggy autumn morning are likely to spot dew-strewn spider webs. The webs, present all year round, are at their most visible at this time of year. Keep an ear out for the deer too, as the rut begins late in the season. It’s foraging season for humans and animals alike and we can watch squirrels and other hibernators gather fallen nuts before the winter. Autumn is also known for an abundance of mushrooms and there is no better place to spot the low-lying fungi than the water’s edge. Look for them around the exposed roots of waterside trees.

Grey skies and pewter water of autumn swimming. Photo: Lance Sagar.

This autumn

The autumn season is unpredictable in any year but this has been no standard year. Here in the UK we’ve seen a heatwave record the hottest temperature in our history by a clear margin. Our lakes and reservoirs are perilously low, as is the groundwater. At the time of writing (mid-October 2022), temperatures remain elevated and whilst the rain has finally started, we have not yet seen enough to register any meaningful improvement to the levels of our reservoirs.

For a while, it appeared that our false autumn (where trees shed leaves early in an attempt to maintain moisture amid high temperatures) would simply become an early autumn. Whether it counts as a second spring or not, there turned out to be more life left in the forests, with trees near to water and away from harsher environments still retaining leaves late into the season.

The waters remain significantly warmer than their winter temperatures, the migrant species are arriving and the waterside trees are turning gold and dropping their leaves. Now is the time then. Our most unpredictable and spectacular season is here, bringing with it the return of our seasonal swim buddies and giving us one last chance to say goodbye to the verdant summer landscape. By the time it is finished, we’ll be halfway to spring.