In one sentence: August is the busiest month on the Sella, but also the one with warm water, the riverside bars open and very long days. Done with your head screwed on —a weekday, a 10:30 start and booking ahead— it is still a brilliant month. Done badly, an obstacle course.
Let us be honest from the very first line: August is the busiest month on the Sella. And we are the ones saying it, having spent more than twenty-five years bringing people down the river from Arriondas and living off the summer. There is no point selling it to you any other way, because when you reach the launch ramp you are going to see it with your own eyes.
But the fact that it is the most crowded month does not mean it is a bad month to do the Sella descent. It means you need to choose the day well, book ahead and, above all, set off at the right time. Done with your head screwed on, the descent in August gives you warm water, the riverside bars in full swing, clear skies and very long daylight hours to take it at your own pace. Done badly —turning up with no booking on a Saturday the 15th at noon— it turns into an obstacle course between canoes that you neither want nor need.
In this guide we tell you which dates to avoid, which times work best, how to handle the water and air temperature in August, what is the deal with horseflies and dogs, and why on Saturday 8 August 2026 the river is closed to tourism for the Descenso Internacional del Sella. If you have calendar flexibility, we will also tell you when it is worth moving your booking to July or the first half of September. Our priority is that your day goes well, not that you book at all costs.
Why August gets so busy (and exactly when)
In August the Sella concentrates most of the active tourism in northern Spain. Families coinciding with the school holidays, groups of friends rounding off their week in Asturias, and the most high-profile event on the river —the Descenso Internacional del Sella, declared a Festival of International Tourist Interest— which draws thousands of spectators every year.
Within the month there are very sharp peaks:
- Peak week (15-20 August): the worst for crowds. It coincides with the Assumption holiday (15 Aug) and with many holidays starting on the 11th or 12th. If you can, avoid these six days.
- The Descenso Internacional Saturday (this year, 8 August 2026): the river is closed to tourism during the competitive starts. You cannot do the tourist descent that Saturday. The days before (Thursday 6 and Friday 7) and Sunday 9 you can, although still with huge crowds.
- Weekends in general: Saturday and Sunday of any week in August double the crowds compared with a Tuesday or a Wednesday.
- 31 August if it falls on a weekend: the last push before the schools go back, it tends to be very full.
The quietest within August, paradoxically, are the last days of the month on weekdays (Monday to Thursday of the last week), when many families are already getting ready for the back-to-school routine.
Real temperatures in August · water, air and what you will feel
In August the climate in Arriondas and along the navigable stretch of the Sella tends to be very stable:
- Air temperature (highs): between 24 and 28 °C on most days. Some occasional days can climb to 30-32 °C when air comes in from the south, but it is not the norm in the Sella valley.
- Water temperature: between 16 and 19 °C. Warm by northern standards. It feels fresh when you dip your foot in, but it does not take your breath away like in June. For children from five years it is entirely manageable.
- Hours of sunlight: a good fourteen hours. The sun rises around 07:00 and sets after 21:30. You have plenty of margin for a relaxed descent with a stop to eat.
- Chance of rain: low, but we are in Asturias and it is never zero. A short shower in the mid-afternoon is possible one day in every four or five.
The important thing for your body: you do not need a wetsuit. You will go out in your swimwear and an old T-shirt, and the water —when it splashes or when you get in on purpose— is going to feel pleasant. Children and adults who feel the cold appreciate it enormously compared with June or the end of September. If you want to understand properly when the river is at its best, we break it all down in the best time to do the Sella descent.
Anti-crowd strategy · the five decisions that change the day
There is no magic wand, but there are five levers that, combined, guarantee you a descent in August with no stress:
- 1. Set off early. We open at 10:30 in the morning and it is the best time of day to start paddling. Most of the big companies move their people between 11:30 and 13:00. If you are already on the water at 10:45, you are ahead of the bulk of the canoes for the whole stretch. We go deeper into it in what time of day has the fewest people.
- 2. Choose Tuesday, Wednesday or Thursday. The difference between a Wednesday 19 August and a Saturday 22 August is enormous. We are talking half the canoes, the riverside bars without queues and free changing rooms when you get back.
- 3. Dodge the hot dates. Saturday 8 August (Internacional, river closed to tourism), 14-16 August (the Assumption and peak week) and the last weekend of the month. If your calendar allows it, dodging these seven or eight specific dates solves 80% of the problem.
- 4. Book 5 to 10 days ahead. You do not need to book in February, but turning up in Arriondas on an August Friday with no booking is a gamble. For August weekends, ideally book the week before. For weekdays, three or four days is plenty.
- 5. Work with small companies with controlled capacity. The ones that move 400 or 500 people a day generate inevitable queues at ticket desks, changing rooms and coaches. We work with limited groups (K3 maximum 3 canoes per monitor) precisely so the day does not feel like a funnel. It is a conscious decision; we tell you why on about us.
If you keep just one idea: in August the fight is not against the river, it is against the clock and the calendar. A weekday + a 10:30 start + booking ahead = 80% of the problem solved.
Saturday 8 August 2026 · what happens with the Descenso Internacional
The first Saturday of August in even-numbered years has marked the Sella calendar since 1930. In 2026, the official date falls on Saturday 8 August (not the first Saturday of the calendar, but the Saturday closest to the start of the month according to the organisers). That day the river is not navigable for tourist descents during the competitive start times. It is a safety rule that every commercial operator respects.
What this means for you depending on the plan you have:
- If you want to watch the Internacional: go as a spectator to the starts in Arriondas, to the intermediate bridges or straight to Ribadesella. It is one of the loveliest festivals of the Asturian summer and it has atmosphere from Friday night. You have the full story in the history of the Sella Descent.
- If you want to go down the Sella that weekend: move your descent to Thursday 6, Friday 7 or Sunday 9 August. A word of warning: those three days are the busiest of the entire year. You will have river, yes, but with far more company than usual.
- If peace and quiet is your thing: that whole weekend, better not. Move the descent to midweek or to another week of the month.
More detail on the festival, its official route and why they declared it a Festival of International Tourist Interest is on our page dedicated to the Descenso Internacional del Sella.
The good of August · advantages you do not get in other months
Before it looks like we are putting you off, let us make clear the good things August gives you that you will not find in May, June or September:
- All the riverside bars along the route are open. All six (Riverland, El Oasis, El Prau, El Bosque, La Mediana and Toraño) are running at full tilt. In months like May or late September, some have already closed. In August, a guaranteed stop with a cold drink halfway down. We break them down one by one in the riverside bars of the Sella descent.
- Very long days. If you set off in the morning, you have the whole afternoon ahead to eat slowly, stop at a river beach like Pozo del Arco and reach Ribadesella with no rush.
- Sun practically guaranteed. It is not a desert, but the chance of having a sunny day in August on the lower Sella is far higher than in other months.
- Warm water. As we said above, the 16-19 °C of the water make the voluntary dips inviting, not compulsory for survival.
- A festive atmosphere. The whole valley is in summer mode. Bars with terraces, cider houses full, music through the streets of Arriondas and Ribadesella. If you come in the mood for atmosphere, August delivers; we make the most of it in what to do after the descent in Ribadesella.
Children, pets and August · the details that do matter
With children: August is probably the best month of the year to go down the Sella with little ones. The warm water removes the "I am scared of the cold" factor, the open riverside bars allow stops for an ice cream or a snack, and the long days take the pressure off the timings. The minimum age is still 5 years old and 1.15 m tall for safety. If you want to dig deeper, we have two complete guides: Sella descent with children (main page) and Sella descent with small children (operational detail). And if you are worried about it being tiring, we take that apart in is the Sella descent tiring?.
With pets: yes, pets come down free with us (canine life jacket included). And in August there is a real detail almost nobody mentions: horseflies. There are some, especially between the second half of July and mid-August, above all in the stretches with low vegetation. They are not dangerous, but they bite and can bother the dog. Bring a repellent suitable for dogs (from any vet shop or chemist) and apply it before you set off. The full operational detail in Sella descent with a dog.
Stag/hen dos and big groups in August call for extra advance notice: book at least two weeks ahead, avoid Saturday 8 (Internacional) and the week of the 15th. We have a complete guide in Sella descent for groups and stag/hen dos. Write to us first at info@aventuraenelsella.es to organise a grouped start.
If you have flexibility, consider July or September · honesty first
You would not write this section if you wanted to maximise bookings in August. We write it because we would rather you live a brilliant day than book and come away with a bad taste in your mouth.
- July: very similar to August in temperatures, but with fewer crowds. Especially the first half. If your family calendar allows it, July is our usual recommendation.
- The first half of September: the flow rises slightly with the first rains, the riverside bars are mostly still open, and the crowds drop sharply from the first weekend onwards. One of our favourite times of the year.
- May and June: colder water (12-15 °C in May), but gorgeous rivers, intense greens and zero crowds. For anyone after quiet, these are the months.
To see the month-by-month comparison with all the pros and cons, you have it in detail in the best time to do the Sella descent. And if your doubt is about timings, how long the Sella descent takes sorts out your hourly planning.
Book smart · how to organise your descent in August
To sum up what we have learnt, this is the plan that works for August:
- 1. Choose a weekday if you can. Tuesday, Wednesday or Thursday are the quietest. Avoid 14-16 Aug, the 8 Aug (Internacional, river closed) and the last weekend if it falls at the end of the month.
- 2. Book 5 to 10 days ahead. By website, WhatsApp, phone or email. It is the honest way to guarantee yourself a place and a time. For the same day, call us before you come; if there is a slot in the calendar, we will confirm it right away.
- 3. Set off at 10:30, our opening time. You are ahead of the bulk of the canoes and you have the cleanest river for the first two hours.
- 4. Decide the route by experience:
- Mini route, 7 km: ideal with small children or if you have never paddled. It finishes before the stretch of the final riverside bars.
- Complete route, 14.5 km: the classic Arriondas-Ribadesella. A good four hours with stops at your own pace.
- 5. Consider the Premium option if you want the day with no friction: a start in the open 10:30-12:30 window, reserved changing rooms and lockers.
- 6. Bring: swimwear on, an old T-shirt, footwear that can get wet (water shoes or old trainers), a towel in the car for the way back, water-resistant mineral sun cream, a cap and around €20 in cash for the riverside bars. The full list in what to bring to the Sella descent.
€25 children aged 5 to 12 · €35 adults · pets free with canine life jacket included. Same price for Mini and Complete. Detail in prices and conditions.
Remember: the river closes at 18:00 by order of the Confederación Hidrográfica del Cantábrico. Setting off late is not an option in August.
If you are coming from far away and want to plan the journey, we help you on how to get to Arriondas and where to stay near the descent. And for those who want to see where it all begins, the Sella descent from Arriondas tells you about kilometre zero of the river.
August on the Sella is possible, it is beautiful and it is perfectly enjoyable. It just asks for a bit more planning than other months of the year. If you choose the day well, set off early and book ahead, you take home the river in its brightest version: with sun, with warm water, with the riverside bars open and with that Asturian summer atmosphere only someone who lives it understands. And if you choose us to come along with you, we will do it the way we have been doing it for twenty-five years: with small groups, monitors who are never in a hurry and the feeling —told by our 147 reviews with an average of 4.5 stars— that you are in good hands from minute zero.
See you on the river. Book your descent here and we confirm time and route in under 24 hours in high season, usually the same day.
What you ask us most
- Is it a really bad idea to do the Sella descent in August?
No, but it takes planning. August is the busiest month of the year and the one with the most crowded river, especially at weekends and during the peak week (14-16 Aug). By picking a weekday, setting off at 10:30 and booking 5-10 days ahead, August gives you the river in its brightest version: warm water (16-19 °C), sunshine, very long days and all the riverside bars along the route open.
- Can you do the Sella descent on Saturday 8 August 2026, the day of the Descenso Internacional?
No. That Saturday the river is closed to tourism during the competitive start times of the Descenso Internacional del Sella (International Sella Descent). It is a safety rule that every commercial operator respects. If you want to go down that weekend, move your booking to Thursday 6, Friday 7 or Sunday 9 August (with huge crowds). If you want to watch the Internacional, go as a spectator to Arriondas or Ribadesella.
- Which specific days should you avoid in August?
The hot dates are: Saturday 8 August (Internacional, river closed), 14-16 August (the Assumption and peak week), and the last weekend of the month if it falls near the 31st. Weekends in general double the crowds compared with weekdays. The quietest within August are the Mondays, Tuesdays, Wednesdays and Thursdays of the last week of the month.
- What temperature is the Sella water in August?
Between 16 and 19 °C, warm by northern standards. It feels fresh when you dip your foot in but it does not take your breath away like in May or June. You do not need a wetsuit. You go out in your swimwear, an old T-shirt and footwear that can get wet. The voluntary dips are inviting, not compulsory. For children from 5 years and 1.15 m it is entirely manageable.
- How far in advance do I need to book for August?
For August weekends, ideally book the week before (5-10 days). For weekdays, 3 or 4 days is plenty. You do not need to book in February, but turning up in Arriondas on an August Friday with no booking is a gamble. Book by website, WhatsApp, phone or email; for the same day, call us before you come and, if there is a slot in the calendar, we will confirm it right away.
