Benagil in August: Weather, Sea Temperature and Crowds at the Cave

BENAGIL · AUGUST · ALGARVE COAST

Algar de Benagil is a cathedral with a hole in its roof, and in August the sun climbs high enough to drop a column of light straight onto the sand inside it. The village above is tiny: a slipway, a ramp down to the beach, a handful of restaurants, and a clifftop path running east and west along the prettiest limestone on the Algarve. Almost everything people fly in for happens inside half a mile of coast.

What August hands you is 84.6°F afternoons, 0.12 inches of rain for the entire month and 13 hours 37 minutes of daylight on the 15th. What it takes back is elbow room, because this is the month Europe books off work. And the water, at 66.8°F, is cooler than the photographs let on.

On this page

• August highs, lows and rain days84.6°F days and 0.2 rain days
• Sea temperature for swimmingA 66.8°F sea, and what it feels like
• How busy Benagil gets in AugustCrowds, booking and what we could not price
• Things to do in Benagil in AugustThe cave, Praia da Marinha and the Sete Vales path
• A two-day plan for BenagilTwo days built around sunrise and the boat slot
• August or September on this coast?How August, July and September compare
• Is August a good time to go?Who should come in August, and who should wait

Benagil has no weather station of its own. Every figure here is measured at IPMA’s station 554 at Faro, 5 meters above sea level and roughly 60 km east along the same coast, so treat it as a sea-level coastal reading and not as a guide to high ground inland, which runs colder and far wetter. For the twelve-month view of the region, see our Portugal calendar, and for bases, drives and beaches beyond this village, the Algarve guide.

Benagil weather in August: average highs, lows and rain days

IPMA, the Portuguese institute for the sea and the atmosphere, puts the August average high at 84.6°F and the average low at 67.8°F over 1991-2020, with 0.12 inches of precipitation for the whole month. That comes from a real thermometer in a screen at 5 meters, not from a reanalysis grid cell, and the distinction is worth a few degrees: station and model data routinely disagree most on the overnight minimum.

Measurable rain is close to a rumor. IPMA counts 0.2 days in an average August reaching 1 mm (0.04 inch) and 0.1 day reaching 10 mm (0.39 inch), which works out to one wet day across roughly five Augusts and a genuine soaking in about one August in ten. Those are the Portuguese thresholds, not the 0.10-inch bar most US tables use, so the counts are not interchangeable with the rain-day numbers on an American forecast page. Plan eight straight outdoor days and expect to lose none of them.

Between the 84.6°F afternoon and the 67.8°F small hours sits a spread of 16.8°F, modest by American summer standards and still enough to change what you carry. Midday on an unshaded clifftop wants water, a hat and a real siesta. Dinner outdoors wants one light layer, because the breeze comes off the Atlantic and the terraces above the beach catch it. Our packing guide has the rest of the list.

On August 15 the sun rises at 6:47 a.m. and sets at 8:24 p.m. local time, for 13 hours 37 minutes of daylight (sunrise-sunset.org gives 05:47 and 19:24 UTC, and Portugal keeps clocks an hour ahead through the summer). Light lingers after the sunset hour, so a late swim and a walk back up the ramp both happen without a flashlight.

Can you swim in Benagil in August? Sea temperature and what it feels like

The sea surface off Benagil averages 66.8°F in August. That number is the mean of daily maxima over 2015-2024 from Open-Meteo’s marine series, which makes it a shade warmer than a 24-hour average would be, and it comes from a model rather than a buoy off this beach. Water you meet at eight in the morning reads a little below it; water at five in the afternoon, a little above.

In practice, 66.8°F is swimmable for most adults after a short and undignified adjustment, and cold enough that small children turn blue faster than their parents expect. A shorty wetsuit is standard issue on kayak and paddleboard trips for exactly this reason. Much of the cave floor sits in shadow outside the high-sun hour, and the water inside feels colder than the open beach, so the swim through the arch stays brief unless you are in neoprene.

Wind and swell are the missing measurements. No station on this stretch records sea state, and sea state is what decides whether a boat gets into the cave at all, so we give no wave height and no wind speed for August. Operators call it off on the morning, not the night before. Put the boat on your first full day rather than your last, so a scrubbed departure still has somewhere to go.

How busy is Benagil in August? Crowds, prices and the demand peak

August is when the continent takes its holiday, and a good share of it lands on this coast. That is a calendar fact rather than a price one: we found no occupancy series and no monthly room-rate series for Benagil, so we crown no month the most expensive and quote no percentage. What we can say is that the village itself holds very few beds, and in August the demand for them arrives from everywhere at once.

Book the bed before you book the flight. Most people who visit the cave sleep in Carvoeiro, Lagoa or Albufeira and drive in, which puts the car and its parking inside the plan (tolls and airport desks are in our rental guide, and US routings into Faro in the flights guide). For the last two weeks of the month we would be locking rooms and the cave boat around six weeks out (est.) rather than gambling at the slipway.

On lodging tax we have to leave a hole. We could not verify whether a municipal tourist tax applies to this stretch of coast in August, or at what rate, so no per-night figure appears. Ask when you book rather than at checkout. The broader arithmetic of a Portugal trip, meals, car and nights included, lives in what a trip costs, and bases across the country in where to stay.

If one line of the August budget deserves more money, it is the boat. A first-departure small craft out of Benagil’s slipway buys light inside the cave, minutes inside it, and fewer hulls queueing at the arch beside you. Book the earliest slot an operator sells, then walk the clifftop above the roof opening while you wait for it.

Things to do in Benagil in August

August is the month the light goes vertical. Around the middle of the day the sun stands high enough to send a shaft through the cave’s roof opening onto the sand below, which is the photograph everyone has seen and the reason midday departures sell out first. Stack that against 13 hours 37 minutes of daylight, 0.12 inches of rain for the month and the warmest sea of the three months measured here, and you get a week of water days you can actually schedule.

Algar de Benagil has no land entrance: you arrive by boat, kayak or paddleboard from Praia de Benagil, the small beach at the foot of the village ramp, or you look down at it from the fenced clifftop. East along the coast, Praia da Marinha is the Algarve’s postcard beach and the far trailhead of the Percurso dos Sete Vales Suspensos, the cliff path that runs west to Praia de Vale Centeanes above Carvoeiro. Further west again, the stacks of Ponta da Piedade make the other great boat morning on this coast.

The water at those places barely notices the calendar: 66.8°F in August against 65.4°F in September is a rounding error to a swimmer. The air notices. An 17.8°F gap between the 84.6°F afternoon and the sea is what makes the first ten seconds of an August swim a shock, and it is why the Sete Vales path, which has no shade worth the name, belongs to seven in the morning in this month rather than to three in the afternoon.

Most of the good stuff costs nothing: the beaches, the clifftop viewpoint over the cave roof, the whole Sete Vales walk, and the last swim of the day between seven and the 8:24 p.m. sunset, once the boats have gone home. We could not verify parking charges at Benagil or Praia da Marinha for the summer months, so arrive expecting to pay and be pleased if you do not.

Benagil in August: a two-day itinerary

Day one runs on the light. Up for the 6:47 a.m. sunrise on the clifftop above the cave, into the first boat or kayak slot the operators sell, back on the sand by mid-morning before the 84.6°F part of the day arrives. Lunch, then a flat hour in the shade. At four, walk to Praia da Marinha as the cliffs start throwing shade onto the beach, swim in the 66.8°F water, and take dinner outdoors with a layer on hand for the 67.8°F end of the night.

Day two belongs to the path and the neighbors: the Sete Vales route early, west toward Vale Centeanes, lunch in Carvoeiro, or east to Albufeira if the group wants volume. Rain is not what reroutes an August day here, with 0.2 days reaching 1 mm; wind is. If the boat is canceled at breakfast, swap the two days, walk while the swell runs, and take the cave at first light tomorrow. Faro‘s old town absorbs an unplanned afternoon without complaint.

Benagil in August vs July and September

July and August are near twins on the thermometer: 84.9°F against 84.6°F by day, 67.3°F against 67.8°F at night, and an identical 66.8°F sea (the marine figures come from Open-Meteo’s 2015-2024 series, not from IPMA’s station record). September is where the line bends. Days drop to 79.5°F, the sea to 65.4°F, and the rain normal jumps to 0.85 inches spread across 1.9 days at 1 mm or more, against August’s 0.12 inches and 0.2 days.

Move four weeks later and you trade 5.1°F off the afternoon and 1.7 extra rain days for a coast whose school holidays have ended. Move four weeks earlier and you get July, which is essentially the same month with a hair less rain and exactly the same water temperature. Neither swap changes the swim much, and both change the queue at the slipway a great deal.

Is August a good time to visit Benagil?

Yes, if you came for the cave, the water and a week you can plan without a contingency. A rain normal of 0.12 inches, 13 hours 37 minutes of daylight and a sea that will not get any warmer this year add up to the most reliable outdoor month of the three measured here. No, if your version of this coast involves a parking space at ten in the morning, a quiet stretch of Praia da Marinha, or a dinner table without a reservation.

When the answer is no, September is the swap. You keep 79.5°F afternoons and a 65.4°F sea, you lose the peak-season scrum, and you accept 1.9 rain days at 1 mm or more instead of 0.2. October sits outside the figures we read here, so we make no promises about it. Families tied to a school calendar have no swap available, and for them the fix is scheduling: earlier booking, earlier alarm.

The hour August owns is the middle of the day: sun high enough to drop light through the cave’s roof opening onto lit sand, 13 hours 37 minutes of daylight wrapped around it, and 0.12 inches of rain standing between you and any of it.

The last word

Choose the boat first and build everything else around it: the earliest departure from Benagil’s slipway is the difference between a lit cave and a raft of hulls at the arch. One figure not yet spent: August nights average 67.8°F against July’s 67.3, so of the three months here it is August, not July, that gives the warmest late dinner on a terrace, with the sun still up until 8:24 p.m. on the 15th.

Sources & data for this guide

• August normals, high 84.6°F, low 67.8°F, 0.12 in · IPMA station 554 Faro, 5 m, 1991-2020 · checked Sep 23, 2026
• Rain-day counts at the 1 mm and 10 mm thresholds · IPMA, same station and period · not interchangeable with US 0.10-inch tables · checked Sep 23, 2026
• July and September normals, air only · IPMA station 554 Faro, 1991-2020 · checked Sep 23, 2026
• Sea surface, 66.8°F in July and August, 65.4°F in September, mean of daily maxima 2015-2024 · Open-Meteo Marine API · checked Sep 23, 2026
• Daylight 13 h 37 min, sunrise 05:47 UTC and sunset 19:24 UTC on August 15, converted to local summer time · sunrise-sunset.org · checked Sep 23, 2026
• Faro’s station sits about 60 km east of Benagil, and no station on this stretch measures sea state, so we give no wave height and no wind figure for August.
• We could not verify boat-tour fares, parking charges at Benagil or Praia da Marinha, or any municipal lodging tax, so no price appears above · operators’ departures and hours change, check when you book.

To plan your stay

• Best Time to Visit Benagil: Sea Temperature, Rain Days and the Quiet Months
• Benagil in July: Weather, Sea Temperature, Crowds and What to Do
• Benagil in September: Weather, Sea Temperature and How It Compares to August and October
• Benagil in June: Sea Temperature, Rain Days and How May and July Compare

Nearby places

• Albufeira, Portugal: The Three Zones, the Beaches and the Old Town Hill
• The Algarve: Beaches, Towns and the Two Coasts of Portugal's South
• Carvoeiro, Portugal: the Cove, Algar Seco and the Seven Hanging Valleys Trailhead