Month guide · Serpa, Portugal

Serpa in September: weather and what to expect

In September, Serpa averages highs of 29°C and lows of 17°C, with about 4 rainy days and 26 mm of rain. Highs are 4°C cooler than in August and 5°C warmer than in October. Crowds in the Alentejo are medium.

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

Average high Town-level29°CLow 17°C
Rainy days Town-level426 mm in total
UV index Modelled7High at noon on a clear day
Crowds RegionalMediumThe Alentejo as a whole

Is September a good time to visit?

Good for

No verdicts for Serpa in September yet. They only use climate values that are precise enough to judge with.

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 5°C over the month. A day above 35°C happens in roughly 1 September in 2.

September in detail

Town-level · ERA5-Land
MeasureAugustSeptemberOctober
Average high33°C29°C24°C
Average low19°C17°C13°C
Rainy days (at least 1 mm)148
Total rainfall5 mm26 mm67 mm
Daylight (mid-month)13 h 41 min12 h 29 min11 h 17 min

Crowds, holidays and daylight

Visitor level RegionalMediumNights booked through online platforms in the Alentejo in September 2025: about 50% 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 29 minSunrise to sunset, calculated from the town's coordinates.
PlaceHighRain daysFrom Serpa
Mértola, Alentejo30°C434 km
Minas de São Domingos, Alentejo29°C432 km
Neves, Alentejo29°C421 km

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

How September is changing

Town-level · ERA5-Land

September highs are 2.1°C warmer than in 1991-2000, and September rainfall is about the same (2016-2025 against 1991-2000). Days above 30°C in September went from 9.8 to 14 a year on average.

Questions about Serpa in September

How warm is Serpa in September?

Average highs are 29°C and lows 17°C. August averages 33°C and October 24°C.

Does it rain much in Serpa in September?

About 4 days have at least 1 mm of rain, with 26 mm in total over the month.

Is Serpa busy in September?

In September 2025, nights booked through online platforms in the Alentejo were about 50% of the busiest month, which we count as medium. The figure is for the whole region and leaves out hotels.

How long are the days in Serpa in September?

About 12 h 29 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