Costa Smeralda enjoys a classic Mediterranean climate with long, hot, dry summers and mild, moderately wet winters. Located on Sardinia’s northeastern coast, the region benefits from sea breezes that take the edge off July and August heat, keeping temperatures comfortable even at peak summer. The swimming season runs from late May through mid-October, with sea temperatures peaking at a bath-like 25°C (77°F) in August. Winter is quiet and cool rather than cold , daytime highs rarely drop below 13°C (55°F) even in January , making this a year-round destination for those who prefer uncrowded coastlines and crisp coastal walks over sunbathing. For more detailed information, see our best time to visit guide.
Costa Smeralda Weather by Month: Temperature and Rainfall
The table below shows average high and low temperatures, monthly rainfall, sea temperature, and daily sunshine hours for Costa Smeralda. Data is based on Olbia meteorological station records, representative of the entire Emerald Coast. For more detailed information, see our things to do guide.
| Month | Avg High (°C/°F) | Avg Low (°C/°F) | Rainfall (mm) | Rain Days | Sea Temp (°C/°F) | Sun Hours |
|---|---|---|---|---|---|---|
| January | 13 / 55 | 5 / 41 | 55 | 8 | 14 / 57 | 4 |
| February | 14 / 57 | 5 / 41 | 48 | 7 | 13 / 55 | 5 |
| March | 16 / 61 | 7 / 45 | 45 | 7 | 14 / 57 | 6 |
| April | 18 / 64 | 9 / 48 | 42 | 7 | 15 / 59 | 7 |
| May | 23 / 73 | 13 / 55 | 30 | 5 | 18 / 64 | 9 |
| June | 27 / 81 | 17 / 63 | 15 | 3 | 21 / 70 | 11 |
| July | 30 / 86 | 20 / 68 | 5 | 1 | 24 / 75 | 12 |
| August | 30 / 86 | 20 / 68 | 10 | 2 | 25 / 77 | 11 |
| September | 26 / 79 | 17 / 63 | 38 | 5 | 23 / 73 | 8 |
| October | 22 / 72 | 13 / 55 | 72 | 8 | 20 / 68 | 6 |
| November | 17 / 63 | 9 / 48 | 80 | 9 | 17 / 63 | 4 |
| December | 14 / 57 | 6 / 43 | 68 | 9 | 15 / 59 | 4 |
Costa Smeralda Weather by Month: Spring (March to May)
Spring transforms Costa Smeralda from a quiet winter coastline into a blooming Mediterranean landscape. March starts cool with highs around 16°C (61°F) and some rainy days, but by April the wildflowers , especially the pink rockrose and yellow broom , blanket the granite hillsides. May is the sweet spot: daytime highs reach 23°C (73°F), rainfall drops to 30mm across just 5 days, and sea temperatures climb to 18°C (64°F), warm enough for a bracing swim. The maestrale wind can still blow strongly in March and April, so pack a windbreaker for boat trips to La Maddalena archipelago. For more detailed information, see our events and festivals calendar.
Costa Smeralda Weather by Month: Summer (June to August)
Summer is Costa Smeralda at its peak. June delivers ideal conditions: 27°C (81°F) highs, just 15mm of rain across 3 days, and sea at 21°C (70°F), with 11 hours of daily sunshine. July and August are hotter at 30°C (86°F) but the prevailing mistral breeze off the sea makes the heat feel less oppressive than inland Sardinia. Rainfall is negligible , July averages just 5mm, typically a single brief thunderstorm. Sea temperatures peak at 25°C (77°F) in August, warmer than many Caribbean destinations. Evenings cool to around 20°C (68°F), perfect for al fresco dining at Piazzetta Porto Cervo. Humidity stays moderate at 55-65%, far more comfortable than mainland Italian cities. For more detailed information, see our area and resort towns breakdown.
Costa Smeralda Weather by Month: Autumn (September to November)
September is arguably the best month on the Costa Smeralda: daytime highs of 26°C (79°F), sea still at a comfortable 23°C (73°F), and crowds thinning after the first week. Rain picks up to 38mm but usually falls as short afternoon showers. October sees a noticeable shift: highs drop to 22°C (72°F) and rainfall doubles to 72mm across 8 days, though you still get 6 hours of daily sun. November brings the real change , 80mm of rain, temperatures down to 17°C (63°F), and many beach clubs and seasonal restaurants close by mid-month. The sea retains warmth through October (20°C/68°F), making late-season swimming possible if you’re lucky with weather windows. For more detailed information, see our where to stay recommendations.
Costa Smeralda Weather by Month: Winter (December to February)
Winter on the Costa Smeralda is mild by European standards but most tourist infrastructure shuts down. December and January bring daytime highs of 13-14°C (55-57°F) and nighttime lows around 5-6°C (41-43°F). Rain falls on 8-9 days per month, with December averaging 68mm and January 55mm. February is slightly warmer at 14°C (57°F) with 48mm of rain. Snow is essentially unheard of at sea level , the last measurable snowfall in Porto Cervo was in 1985. Most hotels, beach clubs, and restaurants close from November through Easter, though Porto Cervo Marina stays partially open and a handful of year-round restaurants serve the small local population. If you visit in winter, base yourself in Olbia (30km south) where infrastructure operates year-round. For more detailed information, see our travel tips and FAQ.
Costa Smeralda Weather by Month: Wind and Sea Conditions
Wind is a defining feature of Costa Smeralda’s climate. The maestrale (northwesterly) blows strongest from November through March, bringing clear skies but choppy seas , most boat excursions to La Maddalena don’t operate during these months. The scirocco (southeasterly from the Sahara) occasionally appears in summer, raising humidity and temperatures by 2-3°C for 2-3 days at a time. Summer sea breezes are reliable: the ponente (westerly) picks up around 11am and dies down at sunset, making mornings ideal for calm-water swimming and afternoons perfect for sailing. The Yacht Club Costa Smeralda schedules races to leverage these predictable wind patterns.
