Cagliari (Sardinia) — sää kuukausittain

Forum posters name March as genuinely the windiest month of the year on Sardinia, though conditions vary a lot day to day - one visitor reported mostly sunny weather warm enough to sunbathe on a terrace, typically in the 17-21C range. Sea swimming isn't realistic yet even on a warm, sunny day, with posters noting the water itself stays too cold regardless of air temperature. Posters consistently point out that Cagliari and the south of the island (down toward Oristano) tend to run milder than Sardinia's north, making it a comparatively better bet for anyone visiting the island specifically in March. Overall, the island sees roughly 10-14 rainy days across the month, so packing for both sun and rain is standard advice.

June in Cagliari is already summer: regulars give late 20s and into the 30s, say early June can be hot enough that you will not want to be walking in the middle of the day, and describe beautiful weather day after day with warm evenings. Our row's 29.8C reading as 31C, with 2 precipitation days, is that. The two qualifications are worth the trip. The sea is still on the cusp between cool and pleasant in the first week - our row says 23.6C - so swimming depends on your tolerance. And the island has not woken up yet: outside Cagliari and Alghero, June is quiet until the end of the month, and the beaches can be almost to yourself. The record: 18.2C nights, 14.9mm of rain and 13 hours of sun.

July in Cagliari is properly hot, and the Cagliari forum's most useful contributions are about the city beach rather than the thermometer. Poetto runs roughly eight kilometres from the Sella del Diavolo out to Quartu Sant'Elena, is fifteen minutes away on an urban bus, and divides opinion - convenient and lively, but not among Sardinia's best beaches, and genuinely packed on a July Sunday. The local variable is the mistral, which can drop both air and sea several degrees within a few hours. Regulars also point out that 30C with low humidity and 35C with it are different holidays. The record: 32.9C days that feel like 35C, 20.8C nights, no precipitation days at all, 13.1 hours of sun and a 26.6C sea.

Sardinia-forum threads asking if July-August is really the worst time split into two camps: one side says avoid it outright, too hot and humid with thousands of tourists everywhere and everything fully booked; the other says go as late in August as possible, when many tourists have already left and the most intense heat has started to ease. Both agree on the sea, though - a bath-like warmth that's one of the month's genuine payoffs regardless of which camp is right. Precipitation barely factors into the debate either way; it's not really part of an August trip here. The record: 32.6C days feeling like 34C, 20.5C nights, just 13mm total across 2.8 days, a 26.7C sea, humidity a relatively dry 62 percent and 12.5 hours of sun - properly hot, properly dry, properly crowded until the tail of the month.

Cagliari's forum rates September as possibly the best month of the year in Sardinia — still warm enough for the beach, sea noticeably warmer than earlier in summer, and fewer families with young kids around. Regulars note the Mediterranean's weather has grown less predictable in recent years so rain can't be fully ruled out, but when it comes it's usually a few hours, not days, and restaurants and hotels stay open through the month.

Regulars are specific this month splits sharply around the midpoint, the first 15 days usually still carrying real summer heat well above 18C, the back half turning statistically far less stable with mixed, genuinely unpredictable experiences reported. Our row backs that mild, genuinely wet read, 24.8C over 14.3C nights feeling 14C, with 40.8mm of rain across 6.4 days and humidity at 75 percent. Regulars are consistent this counts as the rainiest month of the year in some parts of the wider region, Villasimius specifically named, though the actual risk stays comparatively low next to other spots. Even late in the month sunny days in the 20-to-26C range remain common, an evening jacket the real adjustment needed. The sea sits at a warm 24.2C. The record: 9.5 hours of sun, a 17.8 kph wind and AQI 44.

Sardinia-forum threads asking whether December is worth it (Cagliari specifically among the destinations discussed) land on a qualified yes: genuinely chilly by the island's own summer standards, but posters are consistent that it rarely turns miserable, and locals themselves keep walking the Poetto Beach promenade right through Christmas Day regardless of the season. Sunny stretches are common enough that a clear December day here can still feel like a genuine treat, sunlight without summer's crowd or heat. The historic castle district and old fortifications are worth exploring regardless of weather, since indoor sightseeing holds up fine on a grey day. Regulars call December's real draw the local Christmas food and market scene, traditional Sardinian sweets and pastries singled out repeatedly. The record: 16.6C days feeling like 14C, 6.6C nights, 51mm across 8.1 days, a 16.4C sea, 82 percent humidity and 7.4 hours of sun.