When is the first shorts day of the year?

The first shorts day of 2026 is probably behind us

We cannot say that for certain: we see only three days ahead, and our own record does not reach far enough back. So we cannot tell you which day it was either, and we would rather leave the date out than invent one.

On 1 January 2027 the count starts over. From that day on, any day can be the first — including a day in January.

What the forecast shows

The verdict per day for Amsterdam, as far ahead as the forecast reaches.

Today

September 26, 2026

21% chance of rain20°CYes

Tomorrow

September 27, 2026

14% chance of rain23°CYes

Day after tomorrow

September 28, 2026

72% chance of rain21°CYes

For each day we use the warmest moment of that day. The bar at the top is about the felt temperature right now; on a day with a cold morning those two can disagree.

What counts as the first shorts day?

The first day of the calendar year on which the KorteBroekAan.nl verdict for Amsterdam turns yes. That verdict is a single rule: felt temperature above 15°C and less than a 90% chance of rain, on the standard setting.

So a warm day in February counts, plain and simple. We do not move the date to a moment that feels more sensible: if the verdict says yes on 19 February, then 19 February was the first shorts day of that year. Even if it stayed cold for the four weeks after it.

Amsterdam is the reference point, the same place the front page uses by default. One fixed place is necessary, otherwise 'the first day' lands on a different date for everyone. If you want the answer for your own town, enter it on the front page.

For the days in the forecast we look at the warmest moment of that day. The live verdict looks at the felt temperature at this moment. The difference is small, but it is real, and you are better off knowing about it than us hiding it.

What we know and what we do not

What we can see live

The verdict for Amsterdam for today and the two days after it. That is the whole of the look-ahead our weather source gives us.

How far back we can look

Our vote record currently holds 400 days with votes; the oldest is August 23, 2025. We cannot look back further than that.

That is why nowhere on this page does it say 'on average the first shorts day falls around 12 April'. A sentence like that needs years of measurements and we do not have them yet. The moment we do, we will put the figure here — not before.

What visitors voted

Today more visitors are voting yes than no.

Those votes come from visitors everywhere, not only from Amsterdam, and they are about what people think themselves. They sit alongside the verdict, not in place of it.

What makes an early shorts day possible

An early first day is almost never the result of a mild winter. It is the result of one weather pattern: an area of high pressure pulling air up from far to the south, landing on a day with little wind and plenty of sun. What matters then is not the season but where the air came from, and in February it can come from Spain just as easily as it does in June.

Sunshine helps more than people expect. At 15°C in full sun with no wind, the felt temperature climbs to around 20°C, comfortably above the threshold. The same 15°C under a closed deck of cloud stalls at about 14°C and just misses. On a day like that the difference between yes and no is not the thermometer, but whether the sun breaks through.

Why March fools people

March is the month of false hope. The sun is noticeably higher than in January, you can feel it on your face, and that feels like spring. But air temperatures in March still sit between 5 and 11 degrees, and the ground and the sea are still cold. It is warm in the sun and cold in the shade, sometimes with a large gap between two spots five metres apart.

Then there is acclimatisation. After three months of winter, 12°C feels like a gift, and your body rewards that feeling with the idea that it is warm enough. That is a real experience, not imagination — but it is not a measurement. Which is exactly why this page looks at the felt temperature and not at how the day feels after a long winter.

Why the first day is usually a false start

The first shorts day of the year is rarely the beginning of anything. Far more often it is a single day that stands out of line, followed by a week in which it is out of the question again. That is in the nature of the pattern that causes it: a southerly flow rarely lasts long, and what follows behind it is usually cooler than what came before.

That does not make the day worth less. It just makes it something other than the start of the season. The first day is an outlier; the season only begins when the no-days stop appearing in between. That is why this page counts the first day separately and says nothing about what comes after it.

The felt temperature decides, not the thermometer

KorteBroekAan.nl works with the felt temperature: the temperature your skin experiences once wind, humidity and solar radiation are counted in. On a spring day that easily differs by several degrees from what the thermometer reads. At 15°C with sun and no wind it feels like about 20°C. At 15°C overcast and still it stays around 14°C. At 15°C overcast with 20 km/h of wind it drops to roughly 11°C.

So the same day produces three different answers depending on whether you are standing in a sheltered spot or riding a bike. The 15°C felt-temperature threshold sits where it sits for a reason: it is the point at which most people still find bare legs pleasant. Below that line it becomes a matter of pushing through rather than comfort.