Yes, September suits anyone who wants beach weather without August’s peak heat: afternoons reach 83°F (28°C) in Cagliari and the sea sits at 76°F (24°C).
Showers return after a dry August, with about four rainy days in the month, and Olbia’s Benvenuto Vermentino wine festival fills the first week of October, so book rooms there early if your trip runs past September.
At a glance
- Afternoon high in Cagliari: 83°F (28°C)
- Night low in Cagliari: 64°F (18°C)
- Rainy days in September: 4 in Cagliari, 4 in Olbia
- Sea near Cagliari: 76°F (24°C)
- Olbia: high 82°F (28°C), low 61°F (16°C)
What is the weather like in Sardinia in September?
| Month | Average high | Average low | Rain | Rainy days | Sea |
|---|---|---|---|---|---|
| August | 90°F (32°C) | 69°F (21°C) | 0.5 in (11 mm) | 1 | 78°F (26°C) |
| September | 83°F (28°C) | 64°F (18°C) | 1.5 in (39 mm) | 4 | 76°F (24°C) |
| October | 75°F (24°C) | 57°F (14°C) | 1.7 in (44 mm) | 5 | 71°F (22°C) |
*Long-term monthly averages.*
September is still warm in Sardinia. Cagliari reaches 83°F (28°C) in the afternoon and cools to 64°F (18°C) at night. Olbia runs a touch cooler at 82°F (28°C) by day and 61°F (16°C) at night. Days are comfortable for sightseeing at midday, and evenings call for a layer.
Cagliari gets four rainy days in the month and Olbia gets four as well, so most days stay dry. Plan outdoor sights such as archaeological sites and park trails for the morning, and keep a light rain jacket in the bag. Sea temperatures near Cagliari are still warm enough for a swim.
August is hotter, with highs of 90°F (32°C) in Cagliari and only one or two rainy days. October is clearly cooler. Cagliari drops to 75°F (24°C) by day and 57°F (14°C) at night, with five rainy days. Olbia in October brings six rainy days. Shifting a month later in either direction changes the packing list more than the plan.
Where to go in Sardinia in September
Cagliari
September gives Cagliari afternoons of 83°F (28°C), warm enough for the city’s parks and cool enough to walk between them. The Cagliari Tourist Office sits on the ground floor of the Town Hall at via Roma 145, a good first stop for maps. The Nuragica museum experience is nearby at via Roma 191.
Olbia
Olbia has the same September pattern as the south, with a high of 82°F (28°C) and a low of 61°F (16°C). Visitors in late September can see the Museo Archeologico di Olbia, the venue of the tasting sessions.
Su Nuraxi di Barumini
Su Nuraxi is the most important nuragic complex in Sardinia and a UNESCO World Heritage site since 1997. One ticket also covers Casa Zapata and the Giovanni Lilliu Centre. The site is open every day of the year, so September has no seasonal gap.
Asinara
Asinara National Park is at the northwestern tip of Sardinia and has been a national park since 1997. Admission is free. Boats leave from Porto Nuovo at Stintino and from Porto Torres, so choose the port closest to where you sleep.
Tharros
Tharros lies in the Sinis landscape between the sea and the ponds. Phoenician colonists founded it at the end of the 8th century BC, and it was abandoned in 1070. Guided tours are offered at the archaeological area.
What to do in Sardinia in September
Su Nuraxi and Casa Zapata at Barumini
The Su Nuraxi area can only be visited with a guided tour. Tours leave every 30 minutes and last about an hour. Tours run in Italian, English and French, so ask for your language when you buy the ticket.
Casa Zapata is a 16th-century noble palace with the nuraghe Nuraxi ‘e Cresia under its floor. Its visit and the Centro Giovanni Lilliu visit each last about 30 minutes, again with a tour every 30 minutes. The single ticket covers all three. Wear comfortable clothing and non-slip shoes, which matters on rainy days.
Asinara trails by bike, horse or train
Asinara has trails across five thousand hectares. You can cover them by mountain bike, on horseback, in an off-road vehicle or by tourist train. The train suits anyone who prefers not to pedal in 83°F (28°C) afternoons.
The Asinara donkey is the park’s symbol, and the marine protected area dates from 2002. Entry costs nothing, and the island can be reached by boat from Porto Nuovo at Stintino or from Porto Torres. Start early to leave time for the return crossing.
Tharros and the Sinis coast
Tharros is a Phoenician foundation from the end of the 8th century BC on a strip between the sea and the ponds. The site has guided tours and a bookshop. September mornings, before the afternoon warmth, are the better time for an open-air site.
After the ruins, the sea is close by. Sea water near Cagliari is 76°F (24°C) this month.
Cagliari’s castle, parks and botanical garden
The Castle of San Michele, in Cagliari at Via Sirai, now hosts exhibitions, lectures and cultural events. Monte Urpinu Park is a place for families, picnics and strolls. Monte Claro Park has paths for walking and jogging.
The botanical garden of Cagliari covers five hectares and was founded in 1866 by Patrizio Gennari. With a night low of 64°F (18°C), late afternoon in the garden is pleasant. The Nuragica museum experience on via Roma is a good indoor option for one of the four rainy days.
Is Sardinia busy in September?
September falls between August, the hottest month with a Cagliari high of 90°F (32°C), and October, which brings more rain. Olbia’s Benvenuto Vermentino week, with public events on the weekend, comes right after the month ends. If your dates run into early October, rooms in Olbia are the item to lock in first.
The Barumini site receives an average of 150,000 visitors each year. Book accommodation ahead for any festival week and for a stay on the coast.
Tourist tax is charged per person and per night, at rates set by each municipality. It can reach 5 euros a night. In Capoterra it applies up to seven consecutive nights and minors up to 14 are exempt. Loiri Porto San Paolo applies its rate for a maximum of ten consecutive days, and in Sardara minors up to 12 are exempt.
Can you swim in Sardinia in September?
Yes, the sea is warm. Near Cagliari the surface averages 76°F (24°C) in September, a monthly average, so a given morning may feel cooler. August is 78°F (26°C) and October drops to 71°F (22°C).
The figures describe the water near Cagliari, so treat them as a guide elsewhere on the island. Asinara has a marine protected area, established in 2002.
What to pack for Sardinia in September
September asks for summer clothes by day and a layer at night, plus something for a few showers.
- A light sweater or jacket for evenings, with lows of 64°F (18°C) in Cagliari and 61°F (16°C) in Olbia.
- A packable rain jacket, since each city gets about four rainy days.
- Non-slip shoes and comfortable clothing for the guided tours at Su Nuraxi in Barumini.
- Swimwear for a sea near 76°F (24°C).
- Sturdy shoes for the trails of Asinara, which cover five thousand hectares.
What to know before visiting Sardinia in September
Su Nuraxi, Casa Zapata and the Centro Giovanni Lilliu are visited by guided tour only. Animals are not admitted, except guide dogs, and only by reservation. Tharros also offers guided tours, so check the start time when you arrive.
The tasting sessions at the Museo Archeologico di Olbia started at 5 p.m. in 2026.
Is September a good time to visit Sardinia?
Yes, especially for travelers who want warm days, a swimmable sea and archaeology in one trip. The weather stays summery without August’s 90°F (32°C) highs.
Compared with August, September trades a little sea warmth (78°F against 76°F) and a few more rainy days for cooler afternoons. Compared with October, it keeps a warmer sea (76°F against 71°F) and mild evenings, since October lows fall to 57°F (14°C) in Cagliari and 54°F (12°C) in Olbia.
If you want swimming, choose September over October. If you want cooler walking days for sites like Su Nuraxi and Tharros, September and early October both work. With children, Monte Urpinu Park in Cagliari is built for families, and minors are exempt from tourist tax in some municipalities, up to age 14 in Capoterra.
Sources
- ncei.noaa.gov (https://www.ncei.noaa.gov/products/wmo-climate-normals), checked 2026-10-30
- italia.it (https://www.italia.it/fr/sardaigne/que-faire/la-sardaigne-au-dela-des-plages-laconi–sadali-et-isili), checked 2026-10-30
- fondazionebarumini.it (https://www.fondazionebarumini.it/biglietti-e-orari/), checked 2026-10-30
- fondazionebarumini.it (https://www.fondazionebarumini.it/fr/home-2/), checked 2026-10-30
- sardegnaturismo.it (https://www.sardegnaturismo.it/en/explore/asinara-national-park), checked 2026-10-30
- cultura.gov.it (https://cultura.gov.it/luogo/area-archeologica-di-tharros), checked 2026-10-30
- informacitta.comune.olbia.ot.it (https://informacitta.comune.olbia.ot.it/eventi/benvenuto-vermentino), checked 2026-10-30
- sardegnaturismo.it (https://sardegnaturismo.it/fr/itineraries/les-jardins-historiques-de-la-sardaigne), checked 2026-10-30