CASCAIS · APRIL · 1991-2020 NORMALS
April finds Cascais between two seasons and comfortable in both. The Atlantic still looks like winter’s ocean, wide and loud out at Guincho, while the afternoons settle at an average high of 67.8°F, warm enough for lunch outdoors and cool enough to walk all day. Lisbon’s airport is close, the coastal rail line ends in town, and plenty of travelers book Cascais as a base with a day in Sintra attached.
What the date hands you is light and room to move: 13 hours 17 minutes of it on April 15, with the sun down at 8:14 p.m. local. What it withholds is any promise about the water, plus a few degrees you would get by waiting for May. Every air figure here comes from one official thermometer, and where that thermometer stands matters more than most tables admit.
THE MONTH AT A GLANCE · CASCAIS IN APRIL
April gives Cascais 13 hours 17 minutes of daylight and average highs of 67.8°F across roughly eight wet days, which makes it a walking month on this coast rather than a swimming one.
IPMA 1991-2020 NORMALS · HIGH 67.8°F · 7.7 WET DAYS · SEA TEMPERATURE NOT VERIFIED
Go for: daylight that runs to 8:14 p.m., mild afternoons on the Guincho-Oitavos dunes, and the climb to Pedra Amarela at 1,332 feet without summer heat on your back.
Think twice before: building the trip around swimming: nights average 53.2°F and we could not verify a sea-temperature series for this coast.
Air normals: IPMA 1991-2020, station 579 Lisboa Gago Coutinho · Daylight: sunrise-sunset.org · full sources at the end
On this page
- April weather in CascaisHighs of 67.8°F and 7.7 wet days
- How cold the mornings get, and what to wearLows of 53.2°F, and the swimming question
- Crowds, prices and the lodging taxA shoulder month, with no rate data to rank it
- Things to do in Cascais in AprilGuincho dunes, Cabo Raso, Pedra Amarela
- A two-day plan for a weekendCoast on day one, serra on day two
- April vs March and May2.7°F warmer than March, 5.2°F cooler than May
- Is April a good time to visit Cascais?Yes for walkers, no for swimmers
Where to sleep, how the trains from Lisbon work and what the town is like in general belong to our Cascais guide, and the whole-country calendar sits in the best-time verdict. April’s own figures start below.
Cascais weather in April: average highs, lows and rain days
| April normal | Figure |
|---|---|
| Average high | 67.8°F (19.9°C) |
| Average low | 53.2°F (11.8°C) |
| Precipitation | 2.50 in |
| Days with 0.04 in or more | 7.7 |
| Days with 0.39 in or more | 2.1 |
| Daylight on April 15 | 13h 17m |
| Sunrise / sunset, April 15 | 6:57 a.m. / 8:14 p.m. local |
IPMA, Portugal’s national weather service, publishes 1991-2020 normals for April at station 579, Lisboa Gago Coutinho: 67.8°F by day, 53.2°F at night, 2.50 inches of rain. That is a real thermometer, not a model grid cell, but it stands at Lisbon’s airport, inland and 341 feet up. Cascais faces the open Atlantic and runs cooler and windier than the station reads, and the high ground of the serra behind town is colder and far wetter again. Pack for the coast on these numbers, not for a mountain trail.
Rain lands on 7.7 days in an average April, counting any day that records 0.04 inch or more, which works out to roughly one day in four. Heavier weather, 0.39 inch or more, shows up on 2.1 days, so expect about two genuine soakings across the month. One caution on the arithmetic: those are IPMA’s own thresholds of 1 mm and 10 mm, not the 0.10-inch threshold American tables use, and the two counts are not interchangeable.
Day and night sit 14.6°F apart, and that single gap decides the suitcase more than the headline high does. A fleece or light sweater for 53.2°F mornings, a windproof shell for the headlands, one layer you can shed by noon, and shoes that behave on wet cobbles. Our packing guide covers the rest of the country, including the Algarve version of the same month.
On April 15 the sun clears the horizon at 6:57 a.m. and drops at 8:14 p.m., giving 13 hours 17 minutes of daylight. That is a morning on the coast, a full afternoon inland, and dinner still arriving in blue light, none of which a February itinerary can promise. Both clock times are converted to local time, which runs an hour ahead of UTC in April.
How warm is Cascais in April?
The two anchor numbers are 67.8°F by day and 53.2°F by night, a spread of 14.6°F. The curve between them is gentle: coolest just before that 6:57 a.m. sunrise, peaking in mid-afternoon, then falling once the sea breeze takes over the shoreline. Out toward Cabo Raso the wind does most of the work on how warm the air feels, and an inland station never registers that part.
At 53.2°F, breakfast outside wants sleeves and a jacket. By two in the afternoon a shirt usually does in the lee of a wall, less so standing on open dune. Swimming stays an open question: we could not verify a sea-temperature series for Cascais, so we publish no water figure at all. When you do find sea tables for this stretch of Atlantic, read them with one eye open, since most of them average daily maxima and therefore run a little warmer than a true 24-hour mean.
Frost is not part of an April here, with a normal low of 53.2°F. IPMA’s monthly normals do not publish a count of nights at or below freezing, so we give no frost-night number rather than guess one.
How busy is Cascais in April? Crowds, prices and the lodging tax
On the calendar, April is a shoulder month on the Estoril coast, sitting after the winter quiet and before the summer run. Beyond that we hold back. We found no occupancy series and no monthly room-rate data for Cascais, so we crown no month cheap and no month expensive, and any table that claims to would be guessing with more confidence than we have.
So take the booking advice as judgment rather than measurement. For an April weekend we would lock the room several weeks out and keep the car flexible, because Cascais is a small town on a small bay and a Lisbon-plus-Sintra plan sends a lot of people to the same handful of streets. Midweek nights are easier, and a five-night stay absorbs a bad-weather day far better than a two-night dash does.
On the tourist tax we have nothing to quote. We could not verify a per-night municipal lodging tax for Cascais, so no percentage and no euro amount appears, and the reliable move is to ask at booking and read the confirmation line by line. Our trip-cost guide handles the wider budget question for Portugal.
The one place where spending more changes April itself is a rental car. The dunes at Guincho and the Sintra-Cascais serra are exactly where mild air and 13 hours of light pay off, and neither is a doorstep walk from the bay. Our car guide covers tolls and insurance before you sign anything at the airport counter.
Things to do in Cascais in April: the Guincho dunes, Cabo Raso and Pedra Amarela
April’s argument is the pairing of two figures: 13 hours 17 minutes of daylight on the 15th while days still top out at 67.8°F. May, on the same station’s normals, reaches 73.0°F, which is lovely on a terrace and warmer work on a climb. For a full day on foot with a headland and a ridge in it, those five degrees matter.
The Sintra-Cascais Natural Park covers 14,583 hectares, about 36,000 acres, across the municipalities of Sintra and Cascais. It was first protected as a Protected Landscape by Decree-Law 292/81 of October 15, 1981, then reclassified as a Natural Park by Regulatory Decree 8/94 of March 11, 1994. Inside it sit the coastal lapies north of Cabo Raso, a karst relief carved along the shoreline, the Guincho-Oitavos dune system with the habitats that hang on there, and Pedra Amarela at 406 meters, 1,332 feet, in the serra. We could not verify an entrance fee or an opening hour for any of them.
Rock and dune do not move with the calendar. The air does, and the same headland at 67.8°F in April and 73.0°F in May makes two different walks, with the April version the one you never have to reschedule to a cooler hour. Two raptors nest in the park, the peregrine falcon and Bonelli’s eagle. ICNF does not date their nesting, so neither do we, and scanning the cliffs costs nothing either way.
We can only use the word free carefully here. No ticket price, no opening hour and no free-admission day could be verified for a Cascais site, because the municipal website publishes an events agenda rather than figures we could read. What the month does hand over at no charge is the coastline itself. Inland, the Colares area keeps its old international wine name and grows fruit varieties of its own: the Colares reinette apple, the rose peach, the thick-skinned lemon and the pearl pear.
Cascais in April: a two-day itinerary
Day one stays on the water. Out by nine with the shell on, onto the Guincho-Oitavos dunes while the light is still low and the crowds still at breakfast, then south along the coast to the lapies north of Cabo Raso for late morning. Lunch in town as the afternoon reaches its 67.8°F, then nothing harder than the bay, the fort and an early drink until the sun goes at 8:14 p.m.
Day two climbs. The serra behind the coast holds most of the park’s endemic plants, and Pedra Amarela at 1,332 feet is a morning’s work with the whole Atlantic underneath it. If the sky turns, and it does on 7.7 days in an average April, trade the ridge for the palaces at Sintra or a Colares cellar, and keep the climb for the next clear morning.
Cascais in April vs March and May
| Normal (1991-2020) | March | April | May |
|---|---|---|---|
| Average high | 65.1°F | 67.8°F | 73.0°F |
| Average low | 50.5°F | 53.2°F | 57.4°F |
| Precipitation | 2.63 in | 2.50 in | 2.00 in |
| Days with 0.04 in or more | 7.2 | 7.7 | 5.7 |
The three months line up in order. April’s 67.8°F days run 2.7°F above March and 5.2°F below May, and the nights follow the same steps, 53.2°F against 50.5 and 57.4. Rain barely moves from March to April, 2.63 inches against 2.50, then drops to 2.00 inches in May as wet days fall from 7.7 to 5.7. The water column stays empty for all three, because we found no sea-temperature series for this coast.
Push four weeks forward and you buy 5.2°F on the day, 4.2°F on the night and two fewer wet days, at the cost of moving closer to the summer calendar. Step back four weeks and you pay 2.7°F in both directions plus 0.13 inch more rain for roughly the same number of wet days. Both neighbors have their own figures in Cascais in March and Cascais in May.
Is April a good time to visit Cascais?
Yes, if the trip runs on walking, day trips and long evenings. Highs of 67.8°F, 13 hours 17 minutes of light and about eight wet days out of thirty is a strong hand for a coast with a natural park attached. No, if it is a beach holiday in the American sense. We have no water temperature to offer you, the wind at Guincho is part of the package, and 53.2°F mornings are not sunbathing mornings.
When warmth is the whole point, May is the shift to make: 73.0°F days, 57.4°F nights, 2.00 inches of rain and 5.7 wet days on the same IPMA normals. Four weeks buys a measurable upgrade in every column we can document. What it does to a room rate we cannot tell you, since no series exists on our side for that.
April’s specific offer is narrow and real: 13 hours 17 minutes of daylight on the 15th while the thermometer still stops at 67.8°F, which is what lets a 1,332-foot climb and a dune walk fit inside one day.
The last word
Plan around the daylight rather than the thermometer. With sunset at 8:14 p.m. and afternoons at 67.8°F, an April day in Cascais splits neatly into coast and serra, and all it asks is a shell in the pack for the 2.1 days that bring real rain. One detail ICNF states plainly: the park’s remnant oak forest survives only in the least accessible corners, threatened holly with it, so the walk that looks least convenient on the map is usually the one worth the extra hour. Book the car, keep one day flexible.
Sources & data for this guide
- April, March and May air normals and rain-day counts · IPMA, climatological normals 1991-2020, station 579 Lisboa Gago Coutinho, altitude 103.9 m · checked Sep 23, 2026
- Station caveat: the thermometer sits at Lisbon’s airport, inland and 341 feet up, while Cascais faces the open Atlantic and the serra behind it is colder and wetter · IPMA · checked Sep 23, 2026
- Rain-day thresholds of 1 mm and 10 mm, which are not the 0.10-inch threshold used in US tables · IPMA · checked Sep 23, 2026
- Daylight, sunrise and sunset for April 15, converted to local time · sunrise-sunset.org · checked Sep 23, 2026
- Park area of 14,583 hectares, Decree-Law 292/81 and Regulatory Decrees 8/94 and 9/94, coastal lapies, Guincho-Oitavos dunes, Pedra Amarela at 406 m, nesting peregrine falcon and Bonelli’s eagle, remnant oak and holly, Colares wine and fruit varieties · ICNF brochure “Conheca o Parque Natural de Sintra-Cascais”, icnf.pt · read Sep 23, 2026
- We could not verify a sea-temperature series, a beach or trail measurement, an opening hour, a ticket price or a lodging-tax rate for Cascais. The municipal site publishes an events agenda rather than figures we could read · noted Sep 23, 2026
- Itinerary shapes and booking advice are editorial judgment, not measurement · confirm hours and rates with operators when you book.