Alentejo in September: Weather, Rain Days and a Two-Day Plan from Évora

ALENTEJO · SEPTEMBER · IPMA NORMALS 1991-2020

September hands the Alentejo back to people who want to walk in it. The Portuguese national weather service puts the average afternoon at Évora at 85.1°F and the dawn at 58.3°F, which is 7.2 degrees off August’s high and nearly ten above October’s. The plain is gold rather than green, the cork oaks still throw the only shade for miles, and the sun holds on until 19:40.

What the month will not give you is a promise about water. We could not verify a sea-surface temperature for the Alentejo coast, so we give no swimming figure and we invent none. On land the arithmetic is friendlier: 1.33 inches of rain across the whole month, spread over 3.6 wet days. Where you sleep is a separate decision, and our where-to-stay guide takes it.

On this page

• Alentejo weather in September85.1°F highs, 1.33 inches, 3.6 wet days
• How hot the afternoons get, how cool the nights fallA 26.8-degree swing inside one day
• Crowds and prices in SeptemberWhat we verified, and what we could not
• Things to do in SeptemberÉvora, Monsaraz and the Alqueva shore
• A two-day itinerary built around the heatDay one in Évora, day two east
• September vs August and October92.3°F, 85.1°F, 75.4°F
• Is September a good time to visit?Yes for walkers, no for swimmers

We would give the region three nights at a minimum: Évora as the base, one day east to the reservoir, one day west toward the coast. Most Americans fly into Lisbon (the flights guide covers the routes) and collect the car on the way out of the city, as our rental guide recommends. The date is the question here. Everything that holds true all year lives in the Alentejo guide.

Alentejo weather in September: average highs, lows and rain days

These are IPMA numbers, the Portuguese national weather service, covering 1991 to 2020, and every figure here comes from station 558 at Évora: a real thermometer standing 247.6 meters up in the plain, not a model grid cell. The distinction matters when you pack. The Alentejo runs from an Atlantic coast to high inland ground, the hills are colder and far wetter than Évora, and the beach towns keep weather of their own.

A month total of 1.33 inches sounds like something you would plan around. Spread over 3.6 days that record 0.04 inch or more, it works out to measurable rain roughly one day in eight, and a September week can pass without a drop. Note the yardstick before you compare tables at home: IPMA counts at 1 mm and 10 mm, not at the 0.10 inch used by US summaries, so the two sets of counts are not interchangeable.

Dawn at 58.3°F and mid-afternoon at 85.1°F is a 26.8-degree swing inside a single day, standard behavior for a dry inland plain. Two climates go in the bag, then: a light layer for the 8 a.m. walk and the evening terrace, linen and a brimmed hat for the hours either side of four. Our packing guide has the rest of the list.

On September 15 you get about 12 hours 29 minutes of daylight, sunrise at 07:12 and sunset at 19:40 in Portuguese summer time. The back end is the useful part. A drive that finishes at seven still shows you the country, sites close well before the light does, and a nine o’clock dinner starts in full dark.

How hot does Alentejo get in September, and how cool do the nights fall?

The month averages 85.1°F by day and 58.3°F at night, 26.8 degrees apart. Averages flatten the tail of any month, and we verified no record figure for September here, so treat 85 as the shape of a typical afternoon rather than a ceiling. Half the day sits well below it: the plain cools fast once the sun drops behind the cork oaks.

In practice you dress twice. Long sleeves at breakfast, nothing heavier than a shirt by ten, shade and water from two until five, then the layer comes back out around nine. On the coast, where the Atlantic runs the thermometer, we have no verified water temperature to offer. If you find one elsewhere, check what it measures: most tables publish an average of daily maxima, which reads a shade warmer than a true 24-hour mean.

Freezing is not a September question in this part of Portugal. We found no frost-day count in the normals we read, and with the average low at 58.3°F the thing to plan for runs the other way: a bedroom that has absorbed an 85-degree afternoon and releases it at midnight. Ask whether the room has real air conditioning or shutters that actually close.

How busy and how expensive is Alentejo in September?

We found no occupancy series and no monthly room-rate series for the Alentejo, so we crown no month the cheapest and none the peak. The calendar is the fact we do hold: the August crowd here is a school-holiday crowd, Portuguese and European, and those holidays end. September inherits the same roads with the schools back in session. For the broader shape of the year, see the 12-month verdict.

That leaves booking to judgment rather than to data, and we could not verify lead times, so no number of weeks appears in our advice. One sequencing rule we will defend: reserve the car before the room. Évora, the Alqueva shore and the coast are driving distances apart, and our getting-around guide lays out what the alternatives cost you in time.

On the municipal tourist tax, we could not verify a rate for Évora or the other Alentejo municipalities, so we give no per-night amount. Where such a tax applies in Portugal it lands as a separate line at checkout rather than inside the nightly rate. Ask the property when you reserve, and budget the trip with our cost guide instead of a guess.

One upgrade genuinely changes September: a place with shade, a pool and cooling you can trust at four in the afternoon, when 85.1°F is doing its work. Everything else, the dinner, the wine, the extra day, buys you the same pleasure it buys in May. The siesta hours are the part of the day this month taxes.

Things to do in Alentejo in September: Évora, Monsaraz and the Alqueva shore

At 85.1°F a full morning outdoors is a pleasure rather than an ordeal, which August at 92.3°F cannot claim. The sun still sets at 19:40, an evening length October gives up along with 9.7 degrees and four extra wet days. Walkable mornings plus long evenings is the combination September owns here, and it decides what fits in a day.

Évora is the base: a walled center you cross on foot, the Roman temple at the top of the rise, the cathedral with its roof terrace, the bone chapel at São Francisco. Check current hours and admission prices on the day of your visit. East, Monsaraz sits on its ridge above the Alqueva reservoir. West, the Costa Vicentina cliffs run past Vila Nova de Milfontes. Our Évora guide goes deeper on the town.

Those stones read the same in February. The air is what moves, from 92.3°F in August to 75.4°F in October, and September’s 85.1 puts the indoor rooms exactly where they belong, in the early afternoon, with the walls and the ridge at either end of the day. Out at Alqueva the dark arrives after 19:40 and the temperature slides toward 58.3°F, which is stargazing weather without a jacket.

What costs nothing: the circuit inside Évora’s walls, the ramparts at Monsaraz, the sky over the reservoir once the last car leaves. We could not verify any free-admission day at the ticketed sites for September, so we name none rather than send you on a wasted walk.

Alentejo in September: a two-day itinerary

Day one belongs to Évora. Sunrise is 07:12, so an eight o’clock start buys three cool hours for the walls, the temple and the cathedral before the coach groups land. Lunch at one, then keep the two-to-five block indoors or beside water, because that is when the 85.1°F average is earned. Back out at five for the ramparts, dinner at eight, and the sun goes at 19:40 while you are at the table.

Day two runs east to Monsaraz: the montado roads in the morning, the ridge in late afternoon, the reservoir below, then the sky. The odds sit with you if the weather turns, since only 3.6 days in an average September record 0.04 inch and just 1.1 day gets 0.39 inch or more. On that one day, swap the ridge for Évora’s interiors and drive between showers.

Alentejo in September vs August and October

August runs 7.2 degrees hotter by day and very nearly dry, 0.24 inch across 0.7 wet days. October drops to 75.4°F and takes on 3.21 inches over 7.7 wet days, more than double September’s count and well over twice its rainfall. Night lows move least of the three, 60.8 to 58.3 to 54.1. No water temperature is verified for any of the three months, so the swimming column stays empty.

Move four weeks earlier and you gain near-certain dry weather and the longest evenings, and you take on the school-holiday calendar plus afternoons in the low nineties. Move four weeks later and hiking becomes comfortable at 75.4°F, while measurable rain jumps from about one day in eight to roughly one in four and the light quits earlier. Our August page makes the other case in full.

Is September a good time to visit Alentejo?

Yes, for the traveler whose days are built on walking a town, driving a country road and eating outside after eight. Dawns at 58.3°F, afternoons at 85.1°F and one wet day in eight make a workable set of conditions. No, for two groups: anyone planning long hikes in full sun, and anyone whose vacation stands or falls on Atlantic swimming, because we cannot hand you a water temperature.

If the answer is no, October is the month to shift to, and the bill is legible: 75.4°F by day, 54.1°F at night, 3.21 inches of rain across 7.7 days. You trade one wet day in eight for one in four and lose evening light with it. August goes the opposite way, 92.3°F and 0.24 inch, which makes a pool holiday rather than a walking one.

Of these three months, September is the only one that pairs a 19:40 sunset with afternoons under 86°F and a rain total of 1.33 inches.

The last word

Reserve the car before the room and let the clock do the planning: mornings on foot, the hot block indoors, the road again at five. One figure to carry while you pack: the thermometer behind all of this stands 247.6 meters up, about 812 feet, in the middle of the plain at Évora. The coast reads cooler, the high ground wetter, so 85.1°F is the interior’s afternoon and nobody else’s. Check monument hours the week you travel, then hold the evening open for the sky over Alqueva.

Sources & data for this guide

• September, August and October normals, station 558 Évora, altitude 247.6 m · IPMA (Instituto Português do Mar e da Atmosfera), 1991-2020 climate normals · checked Sep 23, 2026
• Rain-day counts at the 1 mm and 10 mm thresholds, not the 0.10-inch bar used by US tables · IPMA, 1991-2020 · checked Sep 23, 2026
• Daylight of 12 h 29 min, sunrise 06:12 UTC and sunset 18:40 UTC on Sep 15, converted to Portuguese summer time · sunrise-sunset.org · checked Sep 23, 2026
• We found no occupancy series and no monthly room-rate series for the Alentejo, so we name no cheapest and no busiest month.
• We could not verify a municipal tourist-tax rate for Évora or neighboring municipalities, so we give no per-night amount.
• We could not verify a sea-surface temperature for the Alentejo coast, and we verified no festival or harvest dates for September, so none are named.
• Monument hours and admission prices change · check each site when you book.

To plan your stay

• Things to Do in the Alentejo: Évora, the Almendres Stones, Alqueva's Dark Sky and the Wine Towns
• Best Time to Visit the Alentejo: Weather Month by Month, Summer Heat and the Quiet Season
• Alentejo in August: Weather, Crowds and 92.3°F Days vs July and September
• Alentejo in October: Weather, Rain Days, Crowds and a Two-Day Plan

Nearby places

• Évora, Portugal: the Roman Temple, the Walled Center and the Train from Lisbon
• Cascais, Portugal: the Town Beaches, Guincho and Where to Stay
• Ericeira, Portugal: the Surf Reserve, the Beaches by Level and Where to Stay