Cascais weather in January

January in Cascais: cool, a little rain, with clean air — a good time to visit.

Updated September 2026 · climate normals from ERA5 reanalysis

Cascais🇵🇹 Portugal · Lisbon & Central Portugal · Beach65
  1. 65Jan
  2. 69Feb
  3. 74Mar
  4. 78Apr
  5. 82May
  6. 86Jun
  7. 88Jul
  8. 86Aug
  9. 87Sep
  10. 79Oct
  11. 67Nov
  12. 64Dec

#11 of 12 months in Cascais · #832 of 1413 destinations to visit in January · comfort 65/100 (tier C)

Days
16°C
Nights
11°C
Wet days
8
Sun
7.3 h
Humidity
78%
Daylight
10 h
Cascais, Portugal
Photo: Mateus Castro · Pexels

Traveller notes on Cascais in January

Forum posters describe January daytime temperatures typically in the 13-16C range, with one unusually warm, dry January reaching as high as 21C. Posters frame the broader November-January stretch as the region's wettest window, though the real data suggests January itself tends to run a touch drier than the November-December peak within that same wet season - clear days in January are described by posters as genuinely beautiful, with clear skies, moderate temperatures, and outdoor lunches still very much on the table. Since Cascais is a year-round residential town rather than a purely seasonal resort, posters note most restaurants and shops stay open through winter (aside from brief, staggered breaks), with the real upside being a tourist-free town compared to the summer crush.
Tripadvisor community · January · 1 month ago · Read more on Tripadvisor ↗

Other months in Cascais

Regulars are specific this counts as a genuine sunbathing month when conditions run normal, one visitor even describing early May as scorching and warm enough for paddling in the water despite how early in the season it is. Our row backs that mild, genuinely wet read, 21.9C over 15.3C nights feeling 13C, with 35mm of rain across 4.6 days and a real 23.8 kph wind. Regulars are consistent conditions here stay genuinely changeable rather than guaranteed, a sunny warm day and a cooler rainy one both realistic outcomes depending on exactly when a trip lands. The sea itself stays properly cold this early, well short of comfortable swimming temperatures for most visitors regardless of how warm the air gets. The sea sits at 16.5C. The record: 12.4 hours of sun, humidity 75 percent and AQI 48.
SunbathingPossibleButNotGuaranteed · May · 1 month ago · Read more on Tripadvisor ↗
Cascais-forum threads on November weather call it right at the seasonal hinge: some visitors catch stretches close to beach weather, others land square in grey winter days, and the difference often comes down to which specific week a trip falls in. Posters describe overall luck with the weather as decent more often than not, rain expected but genuinely manageable around a normal sightseeing itinerary rather than a trip-ruiner. Regulars are consistent that swimming is off the table this late in the year - the water and air have both cooled enough that sunbathing and a proper swim no longer make sense, even on a warm afternoon. The clearest upside repeated across threads: the summer crowds are fully gone by November, giving the seaside promenade and old town a noticeably calmer, more local feel that many posters say they prefer to the peak-season version. The record: 18.2C days feeling like 17C, 13.4C nights, 81mm across 9.8 days, a 17.7C sea, 80 percent humidity and 7.5 hours of sun.
PraiaDaRainhaNovemberRegular · November · 1 month ago · Read more on Tripadvisor ↗
Cascais-forum threads on summer wind draw a useful distinction: the town's own small beaches aren't much bothered by it, but Guincho beach just outside town is exposed enough that locals skip it on a windy day - worth knowing before picking a beach based on the town center's calm. August itself is called the peak month for tourists, with the in-town beaches getting properly crowded, especially on weekends when Lisbon locals show up too. The record shows a cooler, breezier month than the sunny reputation implies: 26.5C days feeling like 28C, 18.8C nights, essentially none at all, a 15.9C sea on the cool side for swimming, 76 percent humidity and wind averaging 25 km/h - dry and sunny, but the Atlantic side of Portugal, not the Mediterranean.
GuinchoWindWatcher · August · 1 month ago · Read more on Tripadvisor ↗
June in Cascais is getting busier without being at its height - early dinners still get a table - and the thing regulars organise around is the wind. Flat calm is rare here and some wind is simply the norm, our row putting it at 24.4 kph. Their practical rule is geographic: it is not much of a problem in the town itself or on the small beaches inside it, but on a windy day locals do not go to Guincho, out beyond the edge of town and fully exposed. The water is the other caveat, under 20C on this coast in June - our row says 18.1C. Days can be warm and the nights are basically cool. The record: 23.6C days, 17C nights, 3.1 precipitation days carrying 9.7mm and 12.9 hours of sun.
NotGuinchoOnAWindyDay · June · 1 month ago · Read more on Tripadvisor ↗

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Cascais climate normals — January

Daytime high16°C / 60°F🙂 cool
Nighttime low11°C / 51°F
Feels like (high)14°C / 57°F
Sea temperature16°C / 60°F🥶 cold sea
Rainfall56 mm / 2.2 in🌦 some rain
Rainy days8 days
Humidity78%💦 very humid
Dew point9°C / 47°F
Sunshine7.3 h/day
Daylight9.8 h
Wind23 km/h / 14 mph
Air quality (US AQI)42🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Cascais in January

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Quiettravelers describe it as quiet, Cascais Christmas Village, Christmas holidays in Portugal

Sourced from traveler notes: “…from brief, staggered breaks), with the real upside being a tourist-free town compared to the summer crush.” — Tripadvisor community

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Peak crowdsBusyShoulder seasonQuiet

Best months for Cascais's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Toughest weatherCascais's best weather comes in June, July and September — separate windows, not one continuous season.

JFMAMJJASOND

Best weatherFair weatherToughest weather

What's on in Cascais in January

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Season

    Winter swell season

    1 Oct – 31 MarSurf season

    The Atlantic lows that make winter here grey are the same ones that make it the serious surf half of the year, at Guincho and around the point at Carcavelos.

  • Festival

    Cascais Christmas Village

    20 Nov – 5 Jan · usuallyChristmas & New YearCrowded

    The Parque Marechal Carmona is given over to a ticketed Christmas village from late November, which is what fills the town on winter weekends when the beach cannot. Source ↗

What's on around the world in January →

Nearby, and something's on

Within 300 km of Cascais — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Cascais?

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Cascais in January — FAQ

Is January a good time to visit Cascais?
January in Cascais: cool, a little rain, with clean air — a good time to visit. It ranks #11 of 12 months for Cascais on SeasonMap's comfort score (65/100).
What is the weather like in Cascais in January?
In January, Cascais averages a daily high of 15.7°C and a low of 10.6°C, with about 55.6 mm of rain over roughly 8 rainy days.
What is the air quality in Cascais in January?
Cascais has a mean US Air Quality Index of about 42 in January.

Within 300 km: Sintra's Camellia season around 15 Jan – 20 Mar, and Évora's Olive harvest around 1 Nov – 31 Jan.