Cascais - Things to Do in Cascais in September

Things to Do in Cascais in September

September weather, activities, events & insider tips

September Weather in Cascais

Temperature, rainfall and humidity at a glance

26°C (79°F) High Temp
18°C (64°F) Low Temp
35 mm (1.4 inches) Rainfall
70% Humidity

Is September Right for You?

Weigh the advantages and considerations before booking

Advantages
  • + The Atlantic keeps its summer heat—21°C (70°F) water—so you can still swim at Praia do Guincho while the August hordes are gone.
  • + Hotel rates drop 25-30% after August 31st while weather stays essentially identical.
  • + Menus turn autumnal: goose barnacles, sea urchin, and the first sardines of the season replace summer staples.
  • + Evenings cool just enough to sit outside in the old town without your shirt sticking to the chair.
Considerations
  • Mid-month the ocean wakes up—surf picks up, but by 3 PM any loose umbrella becomes a missile.
  • September 15-30 brings the ‘Indian Summer’ rush: Portuguese families grabbing their last beach days before school gates close.
  • A few beach bars shutter after September 15th, at remote spots like Praia da Adraga.

Year-Round Climate

How September compares to the rest of the year

Monthly Climate Data for Cascais Average temperature and rainfall by month Climate Overview 3°C 10°C 17°C 24°C 31°C Rainfall (mm) 0 48 96 Jan Jan: 14.0°C high, 8.0°C low, 97mm rain Feb Feb: 15.0°C high, 8.0°C low, 69mm rain Mar Mar: 17.0°C high, 10.0°C low, 91mm rain Apr Apr: 19.0°C high, 12.0°C low, 51mm rain May May: 20.0°C high, 13.0°C low, 38mm rain Jun Jun: 23.0°C high, 15.0°C low, 13mm rain Jul Jul: 25.0°C high, 17.0°C low, 3mm rain Aug Aug: 26.0°C high, 17.0°C low, 5mm rain Sep Sep: 24.0°C high, 16.0°C low, 28mm rain Oct Oct: 22.0°C high, 14.0°C low, 69mm rain Nov Nov: 18.0°C high, 11.0°C low, 81mm rain Dec Dec: 15.0°C high, 9.0°C low, 94mm rain Temperature Rainfall

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View Year-Round Climate Guide →

Best Activities in September

Top things to do during your visit

Coastal Cycling Tours - Cascais to Guincho

September’s steady ocean breeze turns the 8 km (5 mile) coastal ride from Cascais Marina to Guincho Beach into pleasure instead of punishment. The path clings to cliffs scented with rosemary and dotted with surfers at Praia do Crismina. Ride before 10 AM for golden light and before afternoon sand-blast kicks in.

Booking Tip: Reserve bikes the night before—shops near the marina undercut hotel concierges every time. Request wider tyres if you’re heading the full route to Guincho.
Sintra-Cascais Natural Park Hiking

The first autumn rains flip the landscape from brown to green overnight. On the 7 km (4.3 mile) trail from Cascais to Boca do Inferno you’ll meet locals picking wild rosemary and pine nuts instead of tourists wielding selfie sticks, and the shade holds until noon.

Booking Tip: Trails are sign-posted, but an 8 AM guided start pairs wildlife action with calm air; by 2 PM the cliff-edge gusts can knock you sideways.
Estoril Coast Sunset Sailing

Sunsets shift earlier, around 7:30 PM, yet the sky still burns that Atlantic orange-pink lens-hunters crave. Wind drops by 6 PM, smoothing the sail past the casino coastline toward Lisbon. Dolphins grow more playful in September—something to do with the shifting water temperature.

Booking Tip: Book the 5 PM boat for honeyed light and the best chance of fins breaking the surface. Most operators throw in hotel pickup from Cascais hotels.
Cascais Old Town Food Walks

Evenings settle at 20°C (68°F)—good for the three-hour tasca crawl locals swear by. Around Largo de Camões the air fills with grilled sardines and fado drifting from unmarked doors. This is when 80-year-olds argue football over vinho verde while tourists are still hunting Wi-Fi.

Booking Tip: Start food tours at 6 PM; most tascas stay shut until 7:30 PM anyway, so you slide in with the regulars.
Guincho Beach Surfing

September serves the year’s most reliable surf—1-2 m swells that clean up as Atlantic winds strengthen. The water’s still warm enough for three-hour sessions sans wetsuit, and crowd density halves once the summer schools pack up.

Booking Tip: Morning sessions 8-11 AM score offshore winds and empty peaks. Afternoons pump bigger sets but add chop—better for intermediates than first-timers.

September Events & Festivals

What's happening during your visit

Early September, peaking September 8
Festas da Nossa Senhora da Assunção

Cascais’ biggest religious festival floods the old town with processions, fireworks over the bay, and food stalls churning out farturas—giant doughnuts that taste like childhood fairs. On September 8th fishermen carry the Virgin Mary’s statue through a flotilla of lights.

Mid September
Cascais Triathlon

Europe’s oldest triathlon, running since 1982, shuts the coastal road between Cascais and Guincho for a day. Spectators turn the route into one long sardine grill, beers in hand by 9 AM.

Essential Tips

What to pack, insider knowledge and common pitfalls

What to Pack
Pack a light windbreaker—after 2 PM the ocean breeze can shave 5°C (9°F) off the thermometer in minutes. Bring SPF 50+; Atlantic UV at 38°N bounces off the water and burns faster than you expect. Take a quick-dry towel—morning fog can linger until 10 AM and you’ll appreciate the fast dry-off. Wear closed-toe shoes on cobblestones—18th-century Portuguese stones turn slick with ocean mist. Throw in a light sweater—by 10 PM it’s 18°C (64°F) and outdoor tables get chilly. Carry a portable charger—GPS drains fast when you’re threading the maze of old Cascais lanes. Bring a reusable bottle; public fountains serve drinkable water all over town, saving euros and plastic. Slip your phone into a waterproof pouch—Guincho waves love soaking unsuspecting photographers.
Insider Knowledge
The 15-minute train from Lisbon to Cascais costs the same as a Paris coffee—sit on the left for uninterrupted ocean views. Locals dine at 9 PM, not 7. Arrive before 8:30 and you’ll be surrounded by fellow tourists. Tuesday’s dawn fish market at Largo D. Luís I is the real deal. Be there by 7 AM to watch restaurants bid for the night’s catch. Praia da Cresmina is the quiet pocket—ten minutes past Guincho where dunes block the wind and you’ll share sand with maybe twenty others.
Avoid These Mistakes
Skip ocean-view rooms if you want sleep—September winds sand-blast balconies and rattle windows by 3 PM. Flip your beach schedule: mornings stay sunny while afternoons can cloud over and gust hard. Don’t assume everything is stroll-distance—the hill between the marina and old town will punish every pastel de nata you’ve eaten.
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