The nortada is a summer wind from the north-northwest that blows along Portugal's west coast mainly between June and September, and coastal residents adapt to it by getting in the water early and picking afternoon spots by which way they face. It comes from a thermal low over the Iberian Peninsula pulling against the Azores High out in the Atlantic (Wikipedia, Nortada). On the Algarve, one yacht-charter guide describes the rhythm plainly: the wind rises around noon, peaks at 15 to 18 knots by mid-afternoon and dies away by sunset (Blue Ocean Club). We have no equivalent published figure for the west coast, so treat that as a shape, not a timetable. People who live by the water stop treating a summer day as one block. Mornings go to open, exposed beaches. Afternoons go to spots that turn their back to the north, or to things that don't mind wind. Evenings sometimes hand the calm back.
One summer day west of Lisbon, read three ways
Picture a household on the coast between Cascais and Ericeira in July. One person surfs before work. One swims distance. One fishes from the rocks when the tide suits. Nobody in the house has a fixed ocean hour. The wind sets it.
Before work: the exposed beaches
The night before, the surfer reads the hourly forecast rather than the daily headline. The open, west-facing beach scores well from first light and then falls away by late morning, because the wind is rising while the swell stays roughly where it was. So the session is at dawn.
The swimmer goes in at the same hour for the opposite reason. No wind chop yet, so the long swim along the beach is still a swim rather than a wrestle. The water is cold. Upwelling sees to that, and it does not care that the air is already warm.
Around midday: the wind fills in
By lunch the north-northwesterly is up. On the exposed beaches the surface turns to texture, then to whitecaps. Near Guincho the local terrain strengthens the wind, which is why that beach is a known windsurfing and kitesurfing spot (Wikipedia, Nortada). The kites arrive about when the surfers leave. Same wind, different customers.
Late afternoon: change the beach, keep the plan
Nobody writes the day off. The surfer drives to a beach that faces away from the north, where the same wind arrives cross-shore or offshore. The swimmer looks for whichever nearby beach is calmest in the late hours instead of going back to the morning one. The angler waits for the evening, when the tide turns near sunset and, if the usual pattern holds, the wind drops with the light.
Why does the nortada get stronger through the afternoon?
Two pressure systems do the work. The Azores High sits over the Atlantic; a thermal low forms over the heated Iberian interior. Air moves from one toward the other, and along the west coast it arrives mainly from the north-northwest (Wikipedia, Nortada). A thermal low is a product of land heating up. That is the reasoning behind the afternoon peak: the hotter the interior gets through the day, the sharper the contrast with the ocean.
The upwelling loop
There is a second engine. Research presented at the European Geosciences Union in 2016 describes a persistent nortada driving upwelling from Galicia to the Algarve, lifting deep, cold, nutrient-rich water onto the shelf. That cold water sharpens temperature and pressure gradients at the coast, which pushes wind speed up further (Rijo et al., EGU 2016). A run of nortada days can help feed the next one.
The reverse shows up too. In July 2026, IPMA meteorologist Jorge Ponte explained that northern beaches had warmer water than the Algarve because the nortada had failed, so sun-warmed water stayed near the coast longer (figueiradafoz.net). We cover the temperature side in more depth elsewhere on the blog.
How strong is a normal nortada, and when does IPMA issue a warning?
A typical Algarve afternoon peaks at 15 to 18 knots, according to the charter guide. That converts to roughly 28 to 33 km/h. Plenty to wreck a west-facing beach and turn a long swim into hard work, but well below the gust level at which IPMA, Portugal's weather institute, starts issuing wind warnings. As reported by Diário Distrito, IPMA's criteria put yellow at gusts of 70 to 90 km/h, orange at 91 to 130 km/h, and red above 130 km/h.
| Figure | Value | Source |
|---|---|---|
| Main nortada season | June to September, mainly NNW | Wikipedia, Nortada |
| Typical Algarve afternoon cadence | Rises around noon, peaks 15–18 kn, gone by sunset | Blue Ocean Club |
| Algarve sea temperature, early summer, nortada blowing hard | 17–19°C (about 63–66°F) | Blue Ocean Club |
| Algarve sea temperature, late August–September | 21–23°C (about 70–73°F) | Blue Ocean Club |
| IPMA wind warnings (gusts) | Yellow 70–90 km/h, orange 91–130 km/h, red above 130 km/h | Diário Distrito |
An ordinary nortada afternoon is a nuisance, not an emergency. The warning colors matter on the days the wind is reinforced, and those are worth checking on IPMA directly.
What a forecast can and can't separate
Our accuracy panel puts average wind error at ±1–3 kn depending on lead time. So a forecast can tell a 5-knot morning from an 18-knot afternoon with room to spare. It cannot reliably tell 15 knots from 17.
Where does the coast amplify the nortada, and where does it hide from it?
Two places are named for local strengthening: Praia do Guincho near Lisbon, and Praia do Martinhal in Sagres, where the wind blows fully offshore (Wikipedia, Nortada). Martinhal is the useful lesson. Strength and direction are separate questions. A beach can get a lot of wind and still have it blowing from land to sea.
At Peel Watch we handle this per spot. Each spot's coastline facing is measured from OpenStreetMap, and its profile carries a wind tolerance plus sheltered wind sectors, which is how the nortada gets modeled. A spot whose sheltered sector covers the north keeps its wind factor up while exposed neighbors drop. Neighboring spots share one offshore forecast; orientation, seabed and tide are what separate them. Why facing matters in general is covered in its own post, so we will leave it there.
One practical habit: residents keep two beaches in mind, an exposed one for mornings and a sheltered one for afternoons, and check a live beachcam on the spot page before committing to the drive.
What changes in a routine built around the wind?
Surfers plan by the hour
The 0–5 score multiplies its factors, so one bad wind hour sinks that hour no matter how good the swell is. Our forecast refreshes four times a day, at 03:30, 09:30, 15:30 and 21:30 UTC. In Portuguese summer time (UTC+1) that is 04:30, 10:30, 16:30 and 22:30 local. The late run is the one to read before bed. The mid-morning run tells you whether the afternoon backup still holds. A 0.2 difference between two spots is noise.
Swimmers look for the calm hour and the lifeguard
Our swim board ranks beaches 0–10 for calmness, a separate scale from the surf score, with a day picker for the calmest hours. Rips, flags and lifeguards are not in that data. National Maritime Authority figures reported by Executive Digest show nine of 12 fatal drownings over two years happened on unsupervised beaches, with the agueiro (rip current) named among the main causes (Executive Digest). A calm hour on an unwatched beach is still unwatched.
People fishing work the evening
For shore fishing, the useful overlap is a turning tide and a dropping wind near sunset. Line up the two on the tides page against the hourly wind. Bring a layer. Upwelled water makes the rocks feel colder than the inland forecast suggests.
The hourly wind, score and best-wind notes for 115+ spots sit side by side on the surf dashboard, which is where the morning-versus-afternoon choice usually gets made. On most summer days, the wind has decided which beach the afternoon belongs to by about 10:30.