Het weer in Capri (Isle of Capri) in september

September on Capri is still swimming weather — the forum puts the sea around 25°C and posters report getting in the water on every September trip unless it was actually raining. Shorts by day, a light jacket or sweater in the evening once the air eases back from a high near 24°C. On crowds it's a month of two halves: the island is packed daily from mid-June to early September, then late September thins noticeably, and weekday day-trips stay quiet because local day-trippers come mainly at weekends. One local caution — jellyfish turn up some years and have been exceptionally bad in a few; beach clubs keep sting spray.

Asked whether late May is swimming weather, regulars say the sea is still cold and some people go in anyway; our column reads 18.9C, which is exactly that answer in a number. What they are firmer about is the boats. The island is already busy in May, the day-trip crowd arrives mid-morning, and the two rules are to come on the earliest ferry and to avoid weekends - the little beach below the town is full by late morning. Air is gentler than the sea at 21.2C reading as 22C, over 15.6C nights, with 76.3mm of rain across 10 days and 11.9 hours of sun. The record: humidity 76 percent, a 16.1 kph wind and AQI 68.

Capri-forum threads asking if August is worth it land on a split verdict: the weather itself is genuinely excellent, the summer pattern of sun and heat holding steady with only the occasional thunderstorm, but posters are blunt that the island turns properly overwhelmed with visitors, since much of Italy takes its own summer break at the same time. The port at Marina Grande is described as packed on arrival, and regulars recommend the earliest possible ferry plus heading straight up to Anacapri ahead of the day-trip crowds. Weekends specifically get singled out as the worst days to attempt a visit. Swimming conditions are called some of the best of the year regardless, warm seas and long, sunny days more than making up for the crowds if timed around the busiest hours. The record: 29.3C days feeling like a punishing 32C, 23.4C nights, just 27mm across 5.2 days, a 25.6C sea, 69 percent humidity and 12.3 hours of sun.

Capri-forum threads on June timing draw a clear line at mid-month: early June is repeatedly rated the better window, before the day-trip ferries start packing the Piazzetta, the funicular and the bus stops with crowds that run heaviest from mid-June through early September. One poster's early-June trip felt less crowded than a late-July visit; by contrast a late-June day trip is described as a conga line off the boat. The Blue Grotto is weather-dependent too - it closes whenever the sea is too rough, so build in a spare day if it's the priority. June's record: 26.2C days feeling like 29C, 20.6C nights, four rainy days, 13.4 hours of sun and a 24.1C sea - the start of the island's warm-water stretch that runs into October.

Capri forum regulars call March a genuine improvement on January and February — “nice enough to walk around in long sleeved t-shirts without a jacket during the day...but cooler at night” — while warning March and April can “change from day to day.” The trade for that mild-but-unsettled weather is real: a lot of restaurants and activities are still closed for the season, locals call it their favorite month specifically because of that quiet, and posters note you'll have parts of the island genuinely to yourself. The Blue Grotto is a coin flip, open or closed depending on sea conditions rather than the calendar. Our record: 12.6°C days, 7.9°C nights, 10 rain days and 0.4cm of snow — cool and unsettled, matching the day-to-day variability the forum describes more than a single reliable read.