It’s 18 April 2026 and my boat is suspended from the crane. And although the cloud cover is thick, the temperature is already 17 degrees, which really whets the appetite for more. As soon as the boat is in the water and we set off across the Kiel Fjord towards our mooring, the anticipation of clocking up the miles grows immeasurably.
I certainly wasn’t the only one feeling that way back then. What was missing that day, however, was the wind. Just 48 hours later, it arrived. And how! Because whilst the Scandinavian high was still sufficiently extensive during the crane-lifting weekend, it retreated northwards two days later, making way for a low-pressure system over Poland. Between the two, an easterly wind built up, reaching up to 40 knots in the Bay of Lübeck. Conditions you certainly don’t need right at the start of the season. Wind, yes, but not quite that much of it straight away.
On top of that, in spring there’s the cold water. After all, when you’re out sailing, you’re inevitably surrounded by it, so the air temperature can hardly be any warmer. That’s why you always need to wrap up warm in April and May, even when the sun is already beating down. Whilst the water temperatures rose only slowly at first, things looked a little different in the air. By the end of April, temperatures had just about reached the 20-degree mark. Just in time for the 1 May bank holiday, they even exceeded it. And just 24 hours later, thanks to a stable high-pressure system, we recorded the first summer’s day almost nationwide – that is, a daily maximum of 25 degrees or more. This was immediately followed, however, by a two-week cold spell, during which there were even some light late-season frosts.
Drought and the first major heatwave
Whether warm or cold, one thing had already become apparent across much of Germany since winter: a rainfall deficit that was set to persist in large parts of the country well into midsummer. The images of historically low water levels in the Rhine and on Lake Constance are still fresh in our minds.
Returning to the weather chronology, by mid-May the next high-pressure system had built up over Scandinavia. A low-pressure system lingered off the British Isles as its counterpart. Without bringing much rain to the UK – between February and September, the island experienced its lowest ever rainfall – the low-pressure system instead brought us the first surge of properly warm air. From 22 May to 2 June, temperatures in inland areas rose to well over 25 degrees, and in the south and west even exceeded the 30-degree mark.
These were the first hot days we’d seen here. Particularly in south-western Germany – and especially in the Breisgau region – a heatwave began which was to last almost without interruption right through to September. The transition from May to June was therefore a smooth one, with warm to hot weather. On top of this, there were the first reports of an even more intense heatwave between Spain and France, with record-breaking readings from over 200 weather stations – some of which had never recorded such high temperatures so early in the year, with some already exceeding 40 degrees.
How heat domes influenced the wind and weather
These heatwaves, which occurred more than seven times in Western Europe this summer, were expected to affect the North Sea and Baltic Sea regions mostly only intermittently and in a less intense form. One can picture them as large heat bubbles that built up over France and extended as far as the UK. Because they are almost circular in shape, these so-called ‘heat domes’ sometimes extend as far as the German coast, but rarely any further. Occasionally, however, these domes would drift over our waters for a few days, such as during the North Sea Week over Whitsun. In a T-shirt and shorts, it already felt like the height of summer. Yet with the high-pressure system situated almost directly over Heligoland at the time, only weak thermals could provide a little sailable wind.
With the start of the Pantaenius Skagen Rund, the weather in northern Denmark suddenly turned stormy. This is because as soon as a new bubble of hot air builds up in western Europe, the air currents flow round this heat balloon. And at that very moment, it creates a corridor over the North Sea and the Baltic Sea through which air masses from the far north flow.
This also explains why, after the heatwave in late May and early June, the weather immediately became changeable and cooler again, whilst the next heatwave was building up between the Balearic Islands and the Bay of Biscay. As a counterbalance, a low-pressure system developed over Scandinavia, resulting in a prolonged spell of cooler weather and stronger north-westerly winds, along with showers, for us sailors between the IJsselmeer and the eastern Baltic Sea.
Kiel Week turns into a battle against the heat
With the start of Kiel Week on 20 June, the time had come, and the next heat dome was so large and extensive that it stretched all the way to Germany. It was set to be a week that could break records. Record-breaking calm winds on the one hand, but also record-breaking heat.
In any case, over the past ten years we have seen the 30-degree mark being exceeded more and more often during the last full week of June off the coast of Kiel. A clear trend can be seen here. After all, this practically never happened until ten years ago. This year, however, there were as many as three days of extreme heat during Kiel Week, peaking on 27 June at 35.8°C. That was just below Kiel’s all-time record of 36.5°C, which was, however, recorded in July 2022. This therefore marked a new monthly record for June. And not only that, but much more besides. Across Germany, the German Weather Service’s approximately 500 weather stations recorded 223 monthly highs and as many as 247 all-time highs. It hasn’t been this hot in Germany since records began in 1880. The absolute maximum of 41.8°C was recorded in Möckern-Drewitz in Saxony-Anhalt.
These Heat It wasn’t just the cruising sailors who felt the effects, but also the athletes taking part in Kiel Week, some of whom were kept ashore due to the lack of wind so as not to be left baking in the sun on the water. Because even though one might think it was bearable out on the water – if there’s absolutely no breeze, it’s no longer pleasant either.
My first Kiel Week as the meteorologist in charge was therefore a memorable one and, in many ways, a sweaty affair. Drinking plenty of water was the order of the day, and ice cube production in the office in Schilksee was in full swing.
The height of summer brings strong north-westerly winds
Following the world’s biggest sailing festival, we moved into July – the first month of high summer. June doesn’t quite count as part of it yet, so there were fears that this might well mark the start of further extremes for us too. And yes, it did get even hotter, with new records set – though only in Western Europe. We were largely spared from further waves of extremely hot air. That said, there was yet another astonishing new high. Namely, on 30 July, when the temperature reached 33.4°C at the Kiel lighthouse. Right in the middle of the water, which was around 9°C cooler. But without wind, it’s hard to cool things down there.
Otherwise, July was relatively uneventful. Right up until the end, we hardly reached 30°C, at least in the coastal regions. But night-time temperatures remained in double figures with striking frequency. And this was despite the fact that, naturally, air masses from the north were once again reaching us in phases. Many summer sailors will certainly be able to confirm this. There were frequent days with a north-westerly wind, which also blew more strongly from time to time. The weather conditions required for this have already been described.
A quick glance at France, which was once again extremely hot, and the exceptionally dry UK shows us what this extensive northward expansion in the atmosphere brings about: low-pressure systems and a pressure equalisation process, originating in Iceland and moving very rapidly across the North Sea to the German and Danish coasts. The greater the difference between high and low pressure, the stronger the wind blows. And at times, it blew very strongly.
The weather window for the trip to Marstal
This also had an impact on my summer sailing trip. Just in time for Travemünde Week, we set off on holiday with the family, though things turned out differently from what we’d originally planned. As I’m the only one in our crew who’s truly sea-worthy, the plan was initially to sail in short stages along the coast of Schleswig-Holstein towards Als. However, as the north-westerly winds showed no sign of letting up, this would have been a real challenge for my inexperienced crew. On 21 July, though, a perfect Weather window The wind was expected to veer slightly westerly as the day went on and remain fairly moderate. So I managed to persuade everyone to take the plunge and head for Marstal. We were not to regret it.
But that also meant casting off by nine o’clock at the latest, because we first had to get to the point where we’d catch the favourable wind behind the Bülke lighthouse. Once we had it abeam, however, the favourable wind was already there and carried us comfortably towards our destination. As the models had shown, a sudden increase in wind with strong gusts was forecast for 5 pm. So we had to be in a safe harbour by then. We were moored in good time, and right on the dot the first powerful gusts hit. Others were clearly aware of this too, because as we entered the harbour there was not a single free box left And so we slotted straight in as the third boat in the convoy. Plenty more boats followed in our wake. After all, the wind was set to pick up even more the next day. Marstal thus became a compulsory stop for countless crews, with the result that the harbour was absolutely bursting at the seams for two days. In the narrow channels, the boats were sometimes moored six abreast.
As we later learnt, the same scene was unfolding opposite us in Bagenkop on Langeland. Left, right, up, down – there was barely any room left for boats. But somehow we managed to sort things out, and everyone helped everyone else. When the wind died down again, everyone streamed out of the harbour in various directions the following morning. As I’d already been keeping an eye on the weather forecast for the following week and could see that a new high-pressure system was set to move in, it was quite clear what weather and wind conditions we could expect. And so we decided to bid farewell to Denmark once again, with a stop-off in Bagenkop. That way, we could still make the most of the north-westerly wind and, with the wind shifting to south-east a week later, sail back home.
This weather plan worked out perfectly. And it had already factored in the likelihood of another day spent in Heiligenhafen harbour during a storm. In fact, after the harbour festival had ended, the weather stations there recorded wind gusts of up to 38 knots during the night, which didn’t abate much the following day either.
In the last week of July, the way was once again clear for a French high-pressure system to bring more heat our way. As expected, the wind began to shift and, coming from the south, pushed us via Lemkenhafen on Fehmarn back into the Bay of Kiel. All of this in a T-shirt and shorts. That was exactly the sort of sailing summer one could wish for. On the day the temperature record was set at the Kiel lighthouse – not far from there – Schilksee was our final port of call. It was stifling heat, which could only be escaped with a sun awning, plenty of water and a dip at the beach. There was even talk of breaking the all-time record for Kiel-Holtenau, but clouds rolling in a little earlier narrowly prevented that from happening.
Unusually warm water in the North Sea and the Baltic Sea
In August, the deadlocked situation continued. At times, low-pressure systems swept through, bringing a heatwave on their leading edge and cooler air on their trailing edge. Incidentally, on a clear, windless night, the cold air from the north was even enough to cause a light ground frost in the inland areas of Schleswig-Holstein. This was followed by the next, weakened heatwave from the west. According to an analysis of global data, it was nevertheless the warmest August since weather records began. Temperatures were already 1.65°C above pre-industrial levels.
Even though our sailing waters did not experience sustained extreme heat during this period, the situation in the water was quite different. As the Federal Maritime and Hydrographic Agency in Hamburg pointed out, temperatures there were not only in the Temperatures in the North Sea are up to 4°C and in the Baltic Sea up to 3°C above the usual summer levels, whilst off Heligoland there was even a 66-day marine heatwave.
No wonder that, under high-pressure systems, hardly any thermal wind could form. So at times there was no wind at all, and then, under low-pressure systems, there was suddenly too much of it. These ups and downs continued throughout the summer and did not stop even after 28 August. That’s when I set off on a 234-nautical-mile voyage. From Amsterdam, I boarded the training yacht belonging to the Benes Sailing School from Föhr – an X-421 – and sailed through the English Channel to Ramsgate.
In strong winds from Amsterdam to Ramsgate
In the hope that the high-pressure system over France would hold, anticipation was building for the a new hunting ground for me with every passing day since we set sail. Although we were drawing closer to France and the high-pressure system there, given the time of year, that system was also set to gradually come to an end here. And so we had to spend our first day in port in IJmuiden. It was already too stormy just twelve hours after setting sail from Amsterdam. Fortunately, however, this lasted only a day. Thanks to the tides, we were able to set sail at 4 am the next morning to cover some distance. This day’s sailing turned out to be almost perfect, despite the tail end of a low-pressure system. Sailing close-hauled took us as far as Vlissingen. From there, with a brief stopover in Nieuwpoort, Belgium, we made our way on to Dunkirk in France.
Here we had to weather the storm once again. For two full days the wind howled through the rigging; the boat listed noticeably in the gusts. I have rarely felt such pressure whilst moored in harbour. Yet the low-pressure system was actually quite far away, with its centre near Iceland. However, with a pressure of 985 hPa and the high-pressure system over southern France acting as a counterbalance, an enormous pressure gradient built up.
Time was ticking away and my deadline for the return journey from London was drawing ever closer. Suddenly, a possible – and perhaps even ideal – weather window for 5 September appeared in the models. The high-pressure system was initially expected to bring a north-westerly wind on the low-pressure side. Perfect for getting as far as Calais. Afterwards, the wind was due to veer south-westerly as a high-pressure wedge moved southwards, coinciding precisely with the change in the tide. We would be pushed through the traffic separation scheme all the way to Ramsgate.
The forecast couldn’t have been better. And that’s exactly how it turned out. The wind and current were pushing us along so strongly that, due to a container ship crossing our path, we had to slow down by furling the headsail and running the engine slightly in reverse. Once past the traffic separation scheme, the log showed speeds of up to 9 knots over ground. We therefore arrived in Ramsgate swiftly in the late afternoon. It was the perfect end to a wonderful and action-packed week of sailing.
What the 2026 sailing season means for the future
So, in this area too, the situation was not really any different from that seen in the preceding weeks on the North Sea or the Baltic Sea. The weather systems alternated with a certain regularity, like the moon and the sun. Here too, the low-pressure systems brought quite a lot of pressure with them. The fact that we no longer saw any prolonged heatwaves here is due to the time of year. Nevertheless, it was still very mild, not only on the water but also on land at night. This was clearly noticeable. Especially as, at the same time, new monthly records were set in the south of France on 4 September.
Nevertheless, the warmth also slowly retreated in western Europe, and the long nights caused the air to cool down increasingly. Consequently, more low-pressure systems developed again at lower latitudes and even made their way as far as the English Channel. The fact that weather patterns over the summer were so entrenched with high-pressure systems, and that the low-pressure systems sometimes brought very strong winds, is clearly linked to the higher temperatures caused by climate change and also to the increased humidity that warmer air masses can hold. Consequently, weather systems have a greater amount of energy at their disposal.
We must adapt to this in future. Furthermore, the fact that these heat domes in particular persist in one location for weeks on end, whilst elsewhere low-pressure systems pass over the same regions time and time again like a string of pearls, is a clear sign of climate-induced changes in atmospheric circulation. We have been observing this behaviour for years. However, these extremely stable heat domes do not necessarily always linger over Western Europe. Next year, such a heat dome could just as easily form over Germany, or – as in 2025 – over Scandinavia, with the corresponding effects on wind and weather in our sailing areas.
If we look at the raw figures for the summer months of 2026 in the North Sea and Baltic Sea region, the figures for rainfall and hours of sunshine were actually rather normal. It was only in terms of temperatures that we were slightly more than 2°C above the expected values. Looking in detail, however, one can repeatedly identify distinctive phases that stood out once again. Across Germany, the summer of 2026 ranks second in the statistics after 2003. However, the persistent heat in the south-west overshadows the cooler and more changeable conditions in the north. In Western Europe, due to the heat dome, it was actually the warmest summer ever recorded.
It is now over, but the seas are still quite warm. Low-pressure systems are also drawing energy from this to herald the arrival of autumn with great force. It will be interesting to see what else lies ahead, including for the coming 2027 sailing season.
Book recommendations
Meteorology for Water Sports Enthusiasts explains the basics for making sound decisions in changeable weather conditions: from air pressure, high and low-pressure systems and weather charts to wind, waves, thunderstorms and rough seas. The book thus complements the ‘Summer 2026’ guide by providing practical tools for better assessing weather forecasts and adapting your sailing plans accordingly.
Sailing conditions in the Baltic Sea focuses specifically on the area between the Kattegat and the Gulf of Bothnia. The book covers wind, sea state, currents and temperatures, as well as typical large-scale weather patterns and changes in the climate. For sailors on the Baltic Sea, it thus provides in-depth regional information on the months characterised by exceptionally warm weather, but also by strong winds.
Have extreme swings between calm, heat and strong winds long since become the new normal for summer sailing trips on the North Sea and the Baltic Sea? Share your experiences from the 2026 season and join the discussion in the comments.
Sebastian Wache
Freier Mitarbeiter