Lisbon Weather in September

🇵🇹 Portugal

25°C

High

18°C

Low

Rain Days

11h

Sunshine

65%

Humidity

Europe › 🇵🇹 Portugal › Lisbon

Updated: March 2026

Is September a Good Time to Visit Lisbon?

8/10

Excellent

September is a excellent time to visit Lisbon (8/10). With 11 daily sunshine hours and only 4 rain days, this month delivers genuinely reliable outdoor conditions, ranking it 6th sunniest of the year in Lisbon. Beach and outdoor-focused visitors will find September ideal, though hotel prices reflect demand and popular sites get crowded by mid-morning. October offers a similar profile at lower hotel rates if dates are flexible. The main practical note: Lisbon's popular sites are busiest between 10am and 3pm regardless of season. Arriving at opening time or after 4pm makes a significant difference to the experience. Planning tips: book accommodation at least 6-8 weeks ahead, as popular hotels fill quickly during September. Purchasing skip-the-line tickets for major attractions in advance saves meaningful time. If you have flexibility, arriving a few days before or after peak weekends reduces both crowds and prices noticeably.

vs August:27°C avg high

Based on 30-year climate normals (1991 to 2020), September in Lisbon averages 25°C by day and 18°C overnight, a range that places it firmly in the warmer tier of the annual calendar. The month records approximately 11 sunshine hours per day and 29mm of total rainfall across 4 wet days, giving it a sunshine-to-rain ratio that is decidedly favourable for outdoor travel.

25°C

Avg High

18°C

Avg Low

4 days

Rain Days

11h

Sunshine

65%

Humidity

Temperature in Lisbon in September

The 7°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. Humidity averages 65%, which is comfortable for most visitors. On warmer days, lighter fabrics help with the mild stickiness in the afternoon. UV index averages 6 this month, classed as moderate. Sunscreen is a sensible precaution for extended outdoor time, particularly at midday. Wind averages 21 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 77°F average high, 64°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).

Temperature in September

Monthly Precipitation (mm)

What to Wear in Lisbon in September

Morning18°CBefore the day warms up

Afternoon25°CPeak daytime temperature

Evening21°CAfter sunset cools down

Packing for Lisbon in September means dressing for 25°C days and 18°C evenings. A light cotton tee with a casual overshirt works well at 25°C, the overshirt doubles as a layer for air-conditioned venues. Evening temperatures settle at 18°C, a modest 7°C drop that a light cardigan or denim jacket covers. European cobblestones reward low-profile walking shoes over flip-flops or heels, with cushioned trainers or leather walking shoes being the practical choice.

💡

Local tip: Many of Lisbon's museums and galleries maintain cool interior temperatures regardless of outdoor conditions. A compact layer in your daypack lets you move between warm streets and chilled exhibition halls without discomfort.

Events in Lisbon in September

September has no major festivals or public holidays in Lisbon, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.

What to Pack for Lisbon in September

Based on 25°C average highs and 4 rainy days

Light layers for morning and evening
Breathable T-shirts and comfortable trousers
UV-protective sunglasses
SPF 30+ sunscreen
Comfortable walking shoes (a second pair lets the first air out overnight)
Universal travel adapter
Small day pack for city exploration
Reusable water bottle

Best Activities in Lisbon in September

Explore outdoor markets and street food stallsMid-morning (10am-12pm)At 25°C, the temperature is ideal for extended walking without overheating
Guided walking tour of the historic centreMorning or late afternoonComfortable temperatures allow several hours on foot without fatigue
Visit rooftop viewpoints and observation decksGolden hour (1 hour before sunset)Warm clear evenings provide exceptional visibility for panoramic photography
Day trip to the surrounding countryside or coastFull day (depart by 8am)September is reliably dry enough for rural day trips without weather risk
Afternoon in a world-class museum or galleryAfternoon (2-5pm)Pairs well with outdoor morning activities and provides a mid-day rest from sightseeing
Coffee-house or traditional cafe culture experienceMid-morning or post-lunchA cultural ritual in this region that rewards slow appreciation regardless of weather
Evening live music, theatre, or opera performanceEvening shows typically at 7-9pmConsistent evening temperatures make getting to and from evening venues comfortable
Visit the main botanical garden or city park at seasonal peakYear-round; best light in morningSeptember brings distinct seasonal changes to public green spaces worth exploring
Try the seasonal farmer's market for local produce and street foodSaturday morning markets typically 8am-1pmSeptember seasonal produce is at peak availability, offering dishes not found at other times of year

Why is Lisbon warm in September?

Lisbon's September weather is dominated by the Azores High, a semi-permanent subtropical anticyclone that blocks Atlantic rain systems from reaching the Mediterranean. As a result, September delivers reliably sunny, dry conditions with temperatures averaging 25°C. The sea moderates extreme heat and keeps overnight lows around 18°C, making the city noticeably more comfortable than inland Mediterranean destinations. Climate data: Open-Meteo ERA5 (1991–2020).

Sunshine Hours

The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.

UV Index

A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate -- wear sunscreen. UV 6-7: High -- hat and SPF 30+ essential. UV 8-10: Very High -- limit midday exposure. UV 11+: Extreme -- seek shade between 10am-4pm.

Rain Days

A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.

Humidity

Relative humidity as a percentage. Below 40%: Dry -- skin and throat may feel parched. 40-60%: Comfortable -- ideal for most people. 60-80%: Sticky -- light, breathable fabrics recommended. Above 80%: Muggy -- heat feels more intense; quick-dry clothing is essential.

Frequently Asked Questions: Lisbon in September

In September, Lisbon experiences average highs of 25°C (77°F) and lows of 18°C (64°F). Expect around 4 rainy days and 11 hours of sunshine per day, with humidity averaging 65%. The 7°C gap between daytime and overnight temperatures is worth planning around: light layers work for most visitors during the day, but an overshirt or cardigan handles the cooler evenings. UV index averages 6, so sun protection is advisable on clear days.

Lisbon typically sees 4 rainy days in September, with total precipitation of around 29mm. This makes September one of the drier months of the year, and a reliable window for outdoor sightseeing and day trips. Rain showers tend to be brief when they do occur. For context, the driest month in Lisbon typically sees 4-6 fewer rain days than September.

Pack light layers, a light jacket for evenings, comfortable walking shoes, and sunscreen for Lisbon in September. Daytime temperatures of 25°C are pleasant, but the evening drop to 18°C means a jacket is essential if you plan to be out after dark. Rain is infrequent with only 4 wet days, so a light rain layer is optional. Comfortable walking shoes are a priority given the amount of ground most visitors cover.

Yes, September is an excellent time to visit Lisbon. With 11 daily sunshine hours and only 4 rainy days, conditions are ideal for sightseeing and outdoor activities. Temperatures averaging 25°C during the day are comfortable for long walks and outdoor dining. This is peak travel season, so booking accommodation in advance and arriving at popular attractions early in the morning helps avoid the busiest periods.

The average high temperature in Lisbon in September is 25°C (77°F), and the average low is 18°C (64°F). The mean daily temperature is approximately 22°C (71°F). The day-to-night range of 7°C is moderate, meaning a single light jacket covers most situations. These are 30-year climate normals based on the 1991 to 2020 reference period; individual years will vary, particularly in transitional months like spring and autumn.

The best month to visit Lisbon is generally June. June offers the most sunshine at 13 hours per day and only 2 rainy days. Average temperatures reach 24°C, making it comfortable for sightseeing, outdoor dining, and exploring the city. If your travel dates are flexible, planning your trip around June gives you the best chance of dry, bright weather.

September is shoulder or low season in Lisbon, meaning fewer tourists and generally lower prices than peak months. With 11 sunshine hours and 4 rainy days, the weather is less of a draw for mass tourism. This is an advantage for travellers who prefer a quieter, more relaxed experience with shorter queues and easier accommodation availability.

In September, Lisbon suits a range of activities thanks to mild temperatures around 25°C. With few rainy days, outdoor activities are highly recommended. Top options include exploring historic neighbourhoods, visiting museums and galleries, local food markets, and day trips to surrounding areas. With 11 hours of sunshine, parks and waterfront walks are particularly enjoyable.

September ranks 6th sunniest of the year in Lisbon, with an average 11 daily sunshine hours. The driest months are July, August, and June. August is the hottest month (27°C avg high); January is the coolest (14°C). From here, temperatures fall 4°C into October. Compared to last month (August: 27°C high, 1 rain days), September is cooler and wetter. September sits in the middle of the annual sunshine ranking for Lisbon, offering a reasonable balance of good weather and manageable crowds.

Year-Round Climate

Month	High	Low	Rain Days	Sun	Details
January	14°C	9°C	9	7h	View
February	14°C	9°C	8	8h	View
March	17°C	11°C	8	10h	View
April	18°C	12°C	8	11h	View
May	21°C	14°C	6	12h	View
June	24°C	17°C	2	13h	View
July	26°C	18°C	1	13h	View
August	27°C	19°C	1	12h	View
September	25°C	18°C	4	11h	View
October	21°C	16°C	9	9h	View
November	17°C	12°C	10	8h	View
December	14°C	10°C	9	7h	View

Other Months in Lisbon

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Plan Your Trip to Lisbon

Best Time to Visit Lisbon Lisbon vs Seville in September Lisbon vs Porto in September

Nearby Destinations with Similar Weather

These cities are within 500 km and experience broadly comparable weather conditions during the same calendar month, making them practical standalone alternatives or worthwhile additions to a longer regional itinerary.

Seville🇪🇸 Spain313 km away

30°C19°C low

Porto🇵🇹 Portugal275 km away

24°C16°C low

Data Sources for Lisbon

Lisbon on Wikipedia Open-Meteo Climate API NOAA National Centers UK Met Office WMO GeoNames

Climate normals represent 30-year averages (1991-2020). Individual years may vary.