Practical guide · Lisbon Coast
Best time to visit Lisbon and the coast for a family stay or a work month
May, June, September and October give warm days, few rain days and a sea that is as warm as it gets (about 19–20 °C in September–October). July and August are hot in the city, cooler on the coast. Winter is mild but wet. Which season suits families, work, surf and sightseeing.
Short answer: May, June, September and October. Warm days, few rain days, and in September and October the sea is at its warmest (about 19.9 and 19.8 °C). July and August are the hottest months in the city (mean max 28.2 and 28.8 °C) and the busiest; the coast is cooler and windier. November to January is mild but the wettest part of the year.
Season by season
| Season | Best for | Watch out for |
|---|---|---|
| Spring (Mar–May) | City walks, a work month | Sea still cold for swimming |
| Summer (Jun–Aug) | Beach days with lifeguards | Heat in the city, crowds, wind on the coast |
| Autumn (Sep–Nov) | Warmest sea, a work month, autumn events | Rain returns in October, November is the wettest month, lifeguards gone after September |
| Winter (Dec–Feb) | Mild city days, bigger surf for advanced surfers | Rain on 8–10 days a month, shorter hours at some sights |
Summer in short: the hottest and driest months, with lifeguards on the official beaches of Cascais, Oeiras, Almada, Sintra and Mafra all through July and August and the Santo António festivities on 12–13 June. Heat warnings, the June festivities and beaches without a car: Lisbon in summer.
Autumn in short: September is still summer with the warmest sea, October brings the rain back, and November is the wettest month, with Web Summit and São Martinho. Month by month, events, the 5 October and 1 November holidays and kids: Lisbon in autumn.
Temperatures, rain and sea for every month (IPMA 1991–2020 normals), plus what Lisbon is like in winter: Lisbon weather by month. Christmas, New Year’s Eve and the December holidays: Lisbon in December.
By trip type
- Families with small children: late June to mid-September: warm sea and fewer days over 30 °C than in July–August. Check lifeguard dates for your beach, because they differ: in 2026 Cascais 1 May–30 September; Sintra beaches 30 May–13 September; Ericeira (Mafra) 13 June–13 September [ABAE]. Early June and late September have lifeguards only in Cascais.
- Remote work, a month or more: May–June or September–October; winter works too if you accept 8–10 rain days a month.
- Surf: Ericeira works all year. Advanced beginners do best May–September when waves are smaller; advanced surfers September–April, per a local surf school [Ericeira Surf House]. Guincho has strong north winds in June–August, which suits kitesurfers [Wikipedia].
- City sightseeing: spring and autumn; in July and August the average city day has a max above 28 °C.
Planning around the season
- Lifeguard seasons end in mid or late September even though the sea stays warm into October.
- Book your base: where to stay on the Lisbon coast.
- Flights: the cheapest and dearest months by route are in flights to Lisbon.
- Getting around in any season: getting around the Lisbon coast.
Source references
- IPMA: Normal Climatológica 1991–2020, Lisboa / Instituto Geofísico (station 535, 9.1497W, 77 m): TX, TN, precipitation, rain days, days ≥ 25/30 °C · accessed
- seatemperature.org: Cascais monthly average sea temperature (identical values shown for Ericeira) · accessed
- ABAE: município de Cascais (bathing season 1 May–30 Sep 2026) · accessed
- ABAE: município de Mafra (13 Jun–13 Sep 2026) · accessed
- ABAE: município de Sintra (30 May–13 Sep 2026) · accessed
- Ericeira Surf House: best time to surf Ericeira by level · accessed
- Wikipedia (en): Guincho Beach (strong northern winds June–August) · accessed
Quick answers
What is the best month to visit Lisbon?
On long-term averages, September: mean daily max 26.6 °C, 3.8 rain days, and the sea near its warmest at about 19.9 °C. May, June and October are close behind. These are 1991–2020 IPMA normals, not a forecast.
Is Lisbon too hot in August?
August has the highest mean daily max, 28.8 °C, with about 10 days at 30 °C or more on average (IPMA 1991–2020, Lisboa / Instituto Geofísico). The coast is usually cooler and windier than the city. Heat warnings, beaches and kids in the heat: our Lisbon in summer guide.
Can you swim near Lisbon in October?
The sea is about as warm as in September (around 19.8 °C, modelled), but the 2026 lifeguard seasons ended on 30 September in Cascais and on 13 September at the Ericeira and Sintra beaches. October weather, events and the 5 October holiday: our Lisbon in autumn guide.
When is the rainy season in Lisbon?
October to January: November is the wettest month with 133.9 mm and 9.9 rain days on average; June to August get only 0.6–2.0 rain days a month (IPMA 1991–2020).