מזג האוויר באריסיירה במאי

Regulars mark this as the start of the town's most reliable surf-and-weather stretch, running from now through October, with waves in this window described as fun rather than powerful - a genuinely good match for beginners rather than the bigger winter swells experienced surfers chase. Our row backs the mild, brightening read, 19.1C over 14.6C nights, with 39.2mm of rain across 4.5 days. Regulars are candid that this early in the window everything from sunshine to a rainy day is still possible day to day, with the odds shifting more firmly toward sun as the month goes on and into June. The sea stays cool at 16.5C, more a surf temperature than a lounging one. The record: humidity 78 percent, 12.2 hours of sun, a 22.7 kph wind and AQI 48.

Regulars are honest this month comes down to luck, some trips landing genuinely great beach days back to back, others hitting nothing but rain, the range wide enough that no single verdict really applies. Our row backs that mild, genuinely wet read, 20.5C over 16.2C nights, with a substantial 64.7mm of rain across 8.9 days and a real 20.6 kph wind. Regulars are consistent fewer tourists and a relaxed atmosphere make this a genuinely good month for surfing regardless of the weather roulette, the town itself reading as more pleasant than nearby Sintra, which can feel distinctly damp by comparison. The sea sits at 19.9C. The record: 8.7 hours of sun, humidity 81 percent and AQI 48.

Regulars answering a beginner asking about June give three specifics and none of them is about sunshine. The water is cold - the advice is to hire a thick three-four millimetre wetsuit - and our row puts the sea at 18.2C under air of only 20.9C. The waves are small this month and do not build until around October and November, which is what makes June good for learning and poor for watching. And the lineup is already busy, because the surf schools are out in the middle of the day, so early or late is the answer. Rain is a non-issue at 12mm across 3.7 days, and the light is long: 12.8 hours of sun inside 14.9 of daylight. The record: humidity 79 percent, a 22.9 kph wind and AQI 49.

September is when the Atlantic starts working again here, and regulars are direct that it is the wrong month to learn: conditions at Ericeira are harder than at gentler spots nearby, autumn is high season for waves, and a World Championship qualifying event is held on this coast in the last week of the month. The swells keep building into October and November. For everyone else September is the pick of the year - our row gives 22C and 26.7mm across 3.5 precipitation days, warmer and drier than August's grey mornings, with the sea up to 18.7C from 16.7C. Visitors describe it as comfortably busy rather than packed. West-facing, so the sunsets are the other draw. The record: 17.3C nights, humidity 80 percent, 10.7 hours of sun, a 20.9 kph wind and AQI 43.

Ericeira has its own microclimate, several degrees cooler than Lisbon and prone to lovely morning fog, and regulars are clear this is a surf town rather than a sunbathing one: windy, wild water, windbreakers all along the beach. Our row's 23C under a 23 kph wind is that, and 0.4 precipitation days is a month our gauge calls dry while the mornings are grey. On water temperature they say no higher than 22C in August and some call it freezing; ours reads 16.7C, the Atlantic upwelling at its coldest. The waves are modest now and build towards October and November, so August is the learning month rather than the big one. The record: 17.9C nights, humidity 80 percent, 12.1 hours of sun and AQI 39.