Month guide · Sintra, Portugal

Sintra in September: weather and what to expect

In September, Sintra averages highs of 21°C and lows of 17°C, with about 5 rainy days and 31 mm of rain. Highs are 1°C cooler than in August and 2°C warmer than in October. Our rules rate it good for walking and cycling. Crowds in the Lisbon area are high.

Based on 1991-2020 climate data · Updated 1 November 2026 · Sources

Average high Town-level21°CLow 17°C
Sea temperature Modelled18°COpen sea nearby, average for the month
Rainy days Town-level531 mm in total
UV index Modelled6High at noon on a clear day
Crowds RegionalHighThe Lisbon area as a whole

Is September a good time to visit?

Good for

  • Walking and cycling
    Highs of 21°C with about 5 rainy days

Not ideal for

Nothing stands out as a weaker fit.

Daily highs through September

Town-level · ERA5-Land 1991-2020
Usual range (8 in 10 years)Typical high

Highs fall about 2°C over the month. A day above 25°C happens in roughly 1 September in 3; nights below 15°C in about 1 in 2.

September in detail

Town-level · ERA5-Land
MeasureAugustSeptemberOctober
Average high22°C21°C19°C
Average low18°C17°C15°C
Rainy days (at least 1 mm)1510
Total rainfall6 mm31 mm86 mm
Daylight (mid-month)13 h 44 min12 h 30 min11 h 15 min

Crowds, holidays and daylight

Visitor level RegionalHighNights booked through online platforms in the Lisbon area in September 2025: about 75% of the busiest month.

Public holidays in September 2027

No national or regional public holidays.

Local (municipal) holidays are not included.

Daylight mid-month Exact12 h 30 minSunrise to sunset, calculated from the town's coordinates.

The nearest towns with a warmer September. Distances are in a straight line.

How September is changing

Town-level · ERA5-Land

September highs are 0.4°C warmer than in 1991-2000, and September rainfall is about the same (2016-2025 against 1991-2000). Days above 25°C in September went from 0.3 to 0.6 a year on average.

Questions about Sintra in September

Is September a good time to visit Sintra?

Our rules rate September good for walking and cycling (highs of 21°C with about 5 rainy days).

How warm is Sintra in September?

Average highs are 21°C and lows 17°C. August averages 22°C and October 19°C.

Does it rain much in Sintra in September?

About 5 days have at least 1 mm of rain, with 31 mm in total over the month.

Is Sintra busy in September?

In September 2025, nights booked through online platforms in the Lisbon area were about 75% of the busiest month, which we count as high. The figure is for the whole region and leaves out hotels.

How long are the days in Sintra in September?

About 12 h 30 min from sunrise to sunset in the middle of the month.

Sources

Climate: ERA5-Land, Copernicus Climate Change Service (C3S) Climate Data Store, contains modified Copernicus information (CC BY 4.0). Crowds: Eurostat, nights spent in short-stay accommodation booked through online platforms (tour_ce_omn12) (CC BY 4.0). Place names and populations: GeoNames (CC BY 4.0). Climate averages cover 1991-2020. Daylight: calculated from the town's coordinates. Full methodology