SINTRA · SEPTEMBER · PENA PALACE
Sintra’s hill grows its own cloud, and September is the month it goes easy on you. At the nearest official gauge, the 1991-2020 normals give an average high of 80.2°F, an average low of 63.3°F and 1.41 inches of rain spread over 3.7 wet days. August runs hotter and almost bone dry. October collects 4.05 inches.
So the date question has a shape. In September you get afternoons about 4.0°F cooler than August’s, 12 hours 29 minutes of daylight on the 15th, and a sun that sets at 7:45 pm local. You pay for it with rain that has started to return, and with a hilltop that can spend a morning inside a cloud while Lisbon sits in the sun.
THE MONTH AT A GLANCE · PENA PALACE · SEPTEMBER
September gives Pena afternoons around 80.2°F, only 3.7 wet days and a 7:45 pm sunset, so the hill walks well all day and the evening light is yours if you sleep in Sintra.
AVG HIGH 80.2°F · 3.7 WET DAYS · SUNSET 7:45 PM ON THE 15TH · IPMA 1991-2020
Go for: full-length walks between the two hilltops at 80.2°F, a 7:45 pm sunset over the terraces, and rain still limited to 3.7 days in the month.
Think twice before: promising anyone a clear view from Cruz Alta, since the hill makes cloud in every month and the gauge behind these numbers stands 400 m lower.
Normals: IPMA station 579 (1991-2020) · Light: sunrise-sunset.org · full sources at the end
On this page
- Pena Palace weather in September80.2°F days, 1.41 inches, 3.7 wet days
- How cold the hilltop gets at nightLows of 63.3°F, and what to wear
- Crowds and booking at Pena in SeptemberWhere the month sits in the season
- Things to do at Pena Palace in SeptemberThe park, the castle ridge, the village
- A two-day Sintra plan built on PenaHour by hour, dry day and wet day
- September, August or October at PenaHow the three months compare
- Is September a good month for Pena Palace?Our answer, and who should shift
The short version: September is the hill’s last warm month before the rain comes back, and the numbers behind that sentence start below.
Pena Palace weather in September: average highs, lows and rain days
| Measure | September normal, 1991-2020 |
|---|---|
| Average high | 80.2°F (26.8°C) |
| Average low | 63.3°F (17.4°C) |
| Monthly precipitation | 1.41 in |
| Days with 0.04 in or more | 3.7 |
| Days with 0.39 in or more | 1.3 |
| Daylight on September 15 | 12h 29m · sunrise 7:17 am, sunset 7:45 pm local |
Every figure here comes from IPMA, Portugal’s national weather service, and from its 1991-2020 normals at station 579, Lisboa Gago Coutinho. That is a real thermometer at a known altitude, not a model grid cell averaged over a box. It also sits about 25 km from Sintra and some 400 m below Pena’s terraces, and the hill has its own weather: colder, wetter and mistier than the normals below. Read them as the regional floor, then add a layer for the climb.
3.7 days in an average September record at least 0.04 inch of rain, and 1.3 of them bring 0.39 inch or more. Across a week on the hill, that comes out at roughly one wet day, and the wet often arrives as Atlantic mist rather than as a proper shower. One caution on the arithmetic: those are IPMA’s own thresholds, not the 0.10-inch cut most American tables use, so the two sets of rain-day counts do not swap.
Between the average high and the average low sits 16.9°F, and that gap works at both ends of the day. A 9 am start on the ridge wants sleeves. By mid-afternoon, 80.2°F on the low ground means shirt weather. Pack for both in one small bag: a light layer you can tie around your waist, and shoes that grip, because Sintra’s cobbles and garden paths hold damp long after the mist lifts. Our packing guide has the full list.
On September 15 the area gets about 12 hours 29 minutes of daylight. Portugal runs on UTC+1 in September, so sunrise falls at 7:17 am and sunset at 7:45 pm local. The useful consequence is a long evening: the last hour of light runs from roughly 6:45 pm, and that is when the palace walls stop looking like a postcard and start looking like paint.
How warm is Pena Palace in September?
Days average 80.2°F (26.8°C) and nights average 63.3°F (17.4°C) at the gauge, both of them averages of thirty Septembers of daily readings. Individual afternoons land on either side. With August at 84.2°F and October at 72.7°F, the month is a descent, so the first week behaves more like summer and the last week already leans toward fall.
In practice that means a t-shirt plus a light layer for the morning climb, the layer off by late morning, and the layer back on for the terrace at dusk, where the altitude does what the airport gauge cannot show. For rain, take a fold-away shell instead of an umbrella. An exposed hilltop in Atlantic wind is no place for one.
The September normals carry no freezing night, and with lows averaging 63.3°F frost is not part of this month. We also found no sea-surface series for the coast below Sintra, so no water temperature appears here. Where you read one elsewhere, check what it measures: sea figures are usually averages of daily maxima, a little warmer than a true 24-hour mean, and that is why two tables can disagree by a couple of degrees about the same water.
How busy is Pena Palace in September? Crowds, booking and lodging tax
September sits at the end of Portugal’s summer run. European school terms restart in the first half of the month and American trips tilt toward the second half, so the hill thins gradually rather than emptying on a date. What we will not do is rank the month on price: we found no occupancy or room-rate series for Sintra, so we crown no month cheap and no month expensive.
Booking is where September still behaves like high season. We could not verify Pena’s 2026 admission price or its entry-slot rules, so we quote neither. Check Parques de Sintra before you travel, and if timed slots are on sale, take the earliest one offered. The morning hour is the one that changes the visit, because the same hill that collects mist also collects everyone who left Lisbon after breakfast.
Several Portuguese municipalities add a per-night lodging tax, but we could not verify a rate for Sintra, so we give no percentage. Budget for one in case your hotel adds it at checkout, and read the booking confirmation rather than the headline nightly rate. Our trip-cost guide covers how those lines usually show up on a Portuguese bill.
The one upgrade that changes September is a bed in Sintra itself. A day trip from Lisbon costs you both ends of the light: you arrive once the morning cloud has burned off, and you leave before 7:45 pm does its work. Stay on the hill and both hours are yours, the 7:17 am start and the last of the evening. In a month with only 3.7 wet days, those two hours are what September is selling.
Things to do at Pena Palace in September
September opens the long walks that the neighboring months close. At 80.2°F the climb from the village up to the castle ridge is work you can do in the middle of the day. August’s 84.2°F makes the same climb unpleasant, and October’s 8.3 wet days make it a gamble on the forecast.
Five places carry the month, and each sells its own ticket: the Park of Pena with the Cruz Alta high point and the fern valley below the palace, the ramparts of the Moorish Castle on the ridge opposite, Quinta da Regaleira and its initiation well down in the valley, the National Palace of Sintra under the twin conical kitchen chimneys in the village, and the gardens at Monserrate west of town. We could not verify 2026 rates for any of them, so no prices appear here. Our Sintra guide handles the logistics.
What September changes at those places is the air, not the planting. The camellias and tree ferns in Pena’s park stay green all year on that hill, and the mist that feeds them turns up in most months. The variable is temperature: 4.0°F below August, 7.5°F above October, with well under half of October’s wet days. That is the difference between a garden you walk through and a garden you shelter in.
We could not verify a free-admission day at Pena for September, so we promise none. What costs nothing in the month: the streets of Sintra-Vila, the roadside viewpoints on the climb toward the two hilltops, and the woodland lanes between the village and the park gates, all of them usable right up to the 7:45 pm sunset.
Pena Palace in September: a two-day itinerary
Day one runs on the light. The sun is up at 7:17, so be on the hill before 9 and start with the palace while the terraces are still quiet. Give the park two hours after that, downhill to Cruz Alta and back through the fern valley. Lunch in Sintra-Vila around 1:30, when the 80.2°F stretch of the day arrives and shade earns its price. Quinta da Regaleira from 3 to 5, then back up the hill for the last hour before 7:45 pm.
Day two takes the opposite ridge: the Moorish Castle walls in the morning, Monserrate’s gardens after lunch, the village in the evening. If the date lands on one of the month’s 3.7 wet days, reverse the order and go inside, to the National Palace’s painted rooms and chimney kitchens, Regaleira’s tunnels and Pena’s interiors, all of them worth a ticket in weather. Heavy rain is rarer still: 1.3 days in an average September at 0.39 inch or more.
Pena Palace in September vs August and October
| Measure | August | September | October |
|---|---|---|---|
| Average high | 84.2°F | 80.2°F | 72.7°F |
| Average low | 65.3°F | 63.3°F | 58.8°F |
| Precipitation | 0.20 in | 1.41 in | 4.05 in |
| Days with 0.04 in or more | 1.0 | 3.7 | 8.3 |
Set side by side, the three months form a slope. August averages 84.2°F by day and 0.20 inch of rain across a single wet day. September comes in at 80.2°F and 1.41 inches over 3.7 days. October drops to 72.7°F and 4.05 inches over 8.3 days, which is 2.9 times September’s rainfall and more than twice its wet days. Nights follow the same descent, 65.3°F to 63.3°F to 58.8°F.
Shift four weeks and the trade is easy to price. Go back to August and you gain 4.0°F plus near-certain dry weather, and you lose the cooler climbs and the gradual thinning that starts once European school terms resume. Go forward to October and you gain 58.8°F nights for sleeping and a month past the summer travel season, but you hand over 7.5°F of daytime warmth and 4.6 extra wet days. Our August page argues the hotter case.
Is September a good time to visit Pena Palace?
Yes, for anyone who came to walk the hill. Afternoons at 80.2°F, 3.7 wet days and a 7:45 pm sunset suit walkers, garden people and photographers who want the same facade in two lights. No, for anyone who needs a guaranteed clear view from Cruz Alta. Sintra’s ridge makes cloud in every month of the year, and the first hours after 7:17 am are the likeliest to be white.
If the answer is no, October is the month to move to, and it is a trade rather than an upgrade. You take 72.7°F days and a calendar past the summer season, and you accept 4.05 inches of rain across 8.3 days. Travelers who care more about painted interiors than about terraces come out ahead on that swap. For the country-wide picture rather than the hill, see our best-time guide.
Only September pairs afternoons under 81°F with a month total under an inch and a half of rain: August is 4.0°F hotter, October collects nearly three times the water, and neither offers the middle.
The last word
Book the bed in Sintra and the rest falls into place: the 7:17 am start and the 7:45 pm light are what you came for, and neither belongs to a day-tripper watching a return train. One number to keep in mind while you read any forecast for the hill: the thermometer behind every figure here stands at 103.9 m at Lisbon’s airport, and Pena’s terraces sit some 400 m above it. Whatever the app says for Lisbon, carry a layer up.
Sources & data for this guide
- September normals, plus August and October, 1991-2020 · IPMA station 579, Lisboa Gago Coutinho, altitude 103.9 m · checked Sep 24, 2026
- Rain-day counts at the 1 mm and 10 mm thresholds · IPMA, same station and period · checked Sep 24, 2026
- Daylight, sunrise and sunset on September 15, converted from UTC to local time (UTC+1) · sunrise-sunset.org · checked Sep 24, 2026
- Distance and altitude gap between the gauge and Pena’s terraces · IPMA station metadata · checked Sep 24, 2026
- We could not verify Pena’s 2026 admission price, its entry-slot rules or any free-admission day · check Parques de Sintra when you book.
- We found no occupancy or room-rate series for Sintra and no municipal lodging-tax rate, so no crowd ranking and no percentage appear.
To plan your stay
- Best Time to Visit Pena Palace: Weather, Rain Days and the Quiet Months
- Pena Palace in August: Weather, Crowds and How It Compares to July and September
- Pena Palace in October: Weather, Rain Days and How It Compares With September
- Pena Palace in July: Weather, Crowds, Daylight and a Two-Day Sintra Plan