Month by month
| Month | Afternoon | Sea | Rain | Verdict |
|---|---|---|---|---|
| January | 14.6 °C | 15.6 °C | 8 days | Possible, with trade-offs |
| February | 15.9 °C | 15 °C | 7 days | Possible, with trade-offs |
| March | 17.2 °C | 14.8 °C | 9 days | Possible, with trade-offs |
| April | 19.4 °C | 15.8 °C | 9 days | Pleasant — a good time to go |
| May | 22.8 °C | 17 °C | 5 days | Pleasant — a good time to go |
| June | 24.8 °C | 18.1 °C | 4 days | Ideal — one of the best times of year |
| July | 27.7 °C | 18.5 °C | 1 day | Ideal — one of the best times of year |
| August | 28.3 °C | 18.6 °C | 0 day | Ideal — one of the best times of year |
| September | 26.1 °C | 18.8 °C | 4 days | Ideal — one of the best times of year |
| October | 22.9 °C | 18.4 °C | 10 days | Pleasant — a good time to go |
| November | 18.1 °C | 17.5 °C | 10 days | Possible, with trade-offs |
| December | 15.8 °C | 16.5 °C | 7 days | Possible, with trade-offs |
Nearby in September
Before you go
Three things to check once you have picked your dates.
Entry
No visa needed for stays of up to 90 days. Passport valid for at least 3 months. Schengen rules: passport issued less than 10 years ago and valid 3 months after leaving Schengen; under-18s travelling without parents need a certified letter.
For a British passport, per the UK Foreign Office on 11 August 2026. Rules change: check before booking.
Safety
No specific restrictions
Usual precautions apply.
Official advice updated 11 August 2026
Health
Vaccines · hepatitis B if you are not already vaccinated; hepatitis A depending on activities and areas visited. Routine vaccines up to date (measles in particular).
Yellow fever · No yellow fever locally, vaccine not recommended. No entry requirement.
Malaria · None.
Per the CDC (page reviewed 25 August 2026); see a travel clinic a few weeks before departure.
Beau Fixe is not a safety or health authority. These notes summarise dated public texts and link to their source: France Diplomatie (Licence Ouverte 2.0), Foreign, Commonwealth & Development Office (gov.uk, Open Government Licence v3.0), Centers for Disease Control and Prevention (Source: CDC). Only the competent authorities are authoritative.
FAQ
Can you swim in Lisbon in September?
The sea averages 18.8°C in September — too cold for most swimmers.
How hot is Lisbon in September?
Expect 26.1°C in the afternoon and 17.5°C at night, averaged over the last 10 years.
Does it rain a lot in Lisbon in September?
Around 4 days with rain (≥ 1 mm) in the month — 14% of days.