อากาศซันตันเดร์ เดือนกันยายน

September is the month regulars here recommend: still beach weather, fewer people, everything open, and among the more reliable months of the year. Our row runs cooler than their summary - they give around 25C from June to September, the column says 21.9C over 16C - and wetter than the phrase beach weather suggests, 110.8mm across 9.8 days. Both can hold, because their own account of rain here is drizzle in the morning and bright sun in the afternoon, or the other way round. This is the green north, as they put it, and the coast is green precisely because of that. The sea is 22C. The record: humidity 81 percent, 10 hours of sun, a 17.8 kph wind and AQI 48.

Regulars cite the old Spanish saying "en abril, aguas mil" here, showers genuinely common across the whole country this month and northern Spain's own coast no exception, rain a real, expected part of any April visit rather than a surprise. Our row backs that cool, genuinely wet read, 16C over 10.3C nights feeling 8C, with 75mm of rain across 9.2 days and humidity at 78 percent. Regulars are consistent this remains a workable month for exploring the nearby Picos de Europa mountains despite the rain risk, proper waterproof layers the standard advice for any outdoor plans. The sea stays genuinely cold this early, nowhere near ready for swimming regardless of how mild an individual day feels. The sea sits at 14.3C. The record: 10.3 hours of sun, a 19.2 kph wind and AQI 53.

Cantabria has a proverb for this month - until the fortieth of May, do not take your coat off - and regulars quote it because the climate here is Atlantic rather than Spanish: one day beautifully sunny, the next wet, with a good mix the likeliest outcome. They are unapologetic that this is why it is called the Green Coast. Real beach weather, they say, starts at the end of May or in June, so a May trip is for the city and the coastline rather than the sand. Our row agrees at 17.7C over 12.5C with a 16.4C sea and 70.3mm across 9.9 days. Bring layers and a coat for the evening, more so if a north wind gets up. The record: humidity 80 percent, 11.4 hours of sun and a 18.7 kph wind.

June is usually a good month in Santander and regulars will not promise more than that: Cantabria's weather comes off the Atlantic, so there is no guaranteed beach weather in June any more than in August, and a drizzly morning can turn to bright sun by the afternoon or the reverse. Our row's 78.9mm across 11 precipitation days at 82 percent humidity is that variability written down. Their practical answer is geography - the city has beaches on several aspects plus more across the bay, so there is nearly always one out of the wind. Their expectation of around 25C runs warmer than our 20.4C monthly average high; the Atlantic keeps this coast cooler than the Spain most people picture. June is still a safer bet than May for dry hours. The record: 15.5C nights, 11.5 hours of sun, a 19.8C sea and AQI 51.

Cantabria is green for a reason, and the Santander forum says so directly: the coast here is unpredictable, drizzle in the morning and bright sun in the afternoon or the reverse, and the rain is what gives the region its landscape and its rugged coast. August still offers the best odds of the year for sunshine rather than a soaking, with temperatures around 25C from June to September. El Sardinero has the city's two blue-flag beaches within walking distance of the centre. The lesson regulars draw is to take the good weather when it appears rather than plan a day around a forecast. The record: 23.4C days, 17.9C nights, 8.7 precipitation days, 11.5 hours of sun and a 22.7C sea.