Florianópolis has a humid subtropical climate (Köppen Cfa) with warm summers, mild winters and rainfall spread throughout the year. The city sits on an island off Brazil’s southern coast at 27°S latitude, so seasons are the reverse of the Northern Hemisphere. Average highs reach 28 to 30°C in January and February, dropping to 20 to 21°C in July. Rain is heaviest in January and February (160 to 180mm per month), with the driest stretch from June through August (75 to 95mm). The ocean temperature ranges from 18°C in winter to 26°C at the height of summer. Humidity stays high year-round, typically 75 to 85%, which makes summer days feel hotter than the thermometer reads. Because Florianópolis is an island, weather can shift quickly, a sunny morning on one side can turn overcast on the other. UV index hits 11 to 12 in summer, so sunscreen is essential from December through March. See our best time to visit Florianopolis for more information.
Florianópolis Weather by Month
January is peak summer. Average high 29°C (84°F), low 22°C (72°F), rainfall 175mm over 15 rainy days. Sea temperature 25°C. Humidity peaks at 82% and afternoon thunderstorms are common, especially from 3 to 6pm. UV index 12. You will get about 7 hours of daily sunshine despite the cloud buildup. This is the busiest month on the beaches, with traffic jams on SC-401 to the northern beaches.
February brings similar heat: high 29°C (84°F), low 22°C (72°F), rainfall 180mm over 14 days. Sea temperature 26°C (warmest of the year). Carnival often falls in February, drawing massive crowds. Afternoon storms remain frequent. Hotel prices peak during Carnival week. If you are not here for the party, early February outside Carnival dates is slightly less crowded than January.
March starts the transition to autumn. High 27°C (81°F), low 21°C (70°F), rainfall 150mm over 14 days. Sea temperature 25°C. Humidity starts to ease slightly and afternoon storms become less frequent. Still warm enough for beach days, and the crowds thin out noticeably after the first week. March 19 to 25 usually sees good conditions with fewer tourists.
April is one of the best months. High 25°C (77°F), low 18°C (64°F), rainfall 110mm over 10 days. Sea temperature 23°C. Humidity drops to around 78%. You will get more consistent sunshine with fewer afternoon storm interruptions. The water is still comfortable for swimming and the beaches are quiet. Easter week brings a short spike in domestic tourism if it falls in April.
May brings autumn proper. High 22°C (72°F), low 15°C (59°F), rainfall 95mm over 9 days. Sea temperature 21°C. Nights start getting cool enough to need a light jacket. Days remain pleasant for outdoor activities and hiking the island’s trails. Lagoa da Conceição is particularly nice this month with calm waters for windsurfing.
June kicks off winter. High 21°C (70°F), low 13°C (55°F), rainfall 80mm over 8 days. Sea temperature 19°C. This is whale-watching season as southern right whales migrate to the Santa Catarina coast to breed. The water is getting cool for swimming but surfing conditions improve with stronger southern swells. Festa Junina celebrations bring traditional food and bonfires throughout the month.
July is the coldest month. High 20°C (68°F), low 12°C (54°F), rainfall 75mm over 8 days. Sea temperature 18°C (coldest). Clear, crisp days with brilliant blue skies are common between cold fronts. The southern swells produce the best surf of the year, especially at Joaquina and Praia Mole. Pack a warm jacket for evenings, indoor spaces rarely have heating. July school holidays bring a wave of Argentine and Uruguayan tourists.
August remains cool but starts warming slowly. High 21°C (70°F), low 13°C (55°F), rainfall 85mm over 8 days. Sea temperature 18°C. The last month of reliable whale sightings. Winds pick up, making Lagoa da Conceição excellent for kitesurfing and windsurfing. Crowds are minimal outside the Brazilian Fathers’ Day weekend.
September marks early spring. High 22°C (72°F), low 15°C (59°F), rainfall 110mm over 10 days. Sea temperature 18°C. The island gets greener as spring flowers emerge. Rain increases compared to winter but still manageable. A good month for hiking the trails to Costa da Lagoa and Lagoinha do Leste before the summer heat returns.
October warms up noticeably. High 24°C (75°F), low 17°C (63°F), rainfall 130mm over 12 days. Sea temperature 20°C. Longer days return with 13+ hours of daylight. The beaches start filling up on weekends but weekdays remain quiet. Oktoberfest in Blumenau (2 hours away) attracts visitors who often extend their trip to Florianópolis.
November brings summer-like conditions. High 26°C (79°F), low 19°C (66°F), rainfall 130mm over 12 days. Sea temperature 22°C. The water is warm enough for comfortable swimming again. Tourist numbers begin climbing, especially in the second half. The end-of-year university break starts bringing Brazilian students to the beaches from mid-November.
December is early summer. High 28°C (82°F), low 21°C (70°F), rainfall 150mm over 13 days. Sea temperature 24°C. Afternoon thunderstorms return. Christmas to New Year’s Eve is the single busiest stretch of the year. Hotel rates can triple and beaches are packed. Traffic on the island becomes gridlocked. If you visit in December, aim for the first two weeks which are significantly calmer.
Florianópolis Weather Data: Monthly Averages
| Month | Avg High (°C) | Avg Low (°C) | Rainfall (mm) | Rain Days | Sea Temp (°C) | Sun (hrs/day) |
|---|---|---|---|---|---|---|
| Jan | 29 | 22 | 175 | 15 | 25 | 7 |
| Feb | 29 | 22 | 180 | 14 | 26 | 7 |
| Mar | 27 | 21 | 150 | 14 | 25 | 7 |
| Apr | 25 | 18 | 110 | 10 | 23 | 6 |
| May | 22 | 15 | 95 | 9 | 21 | 6 |
| Jun | 21 | 13 | 80 | 8 | 19 | 5 |
| Jul | 20 | 12 | 75 | 8 | 18 | 5 |
| Aug | 21 | 13 | 85 | 8 | 18 | 5 |
| Sep | 22 | 15 | 110 | 10 | 18 | 5 |
| Oct | 24 | 17 | 130 | 12 | 20 | 6 |
| Nov | 26 | 19 | 130 | 12 | 22 | 7 |
| Dec | 28 | 21 | 150 | 13 | 24 | 7 |
Data source: INMET (Brazilian National Institute of Meteorology), 30-year averages from Florianópolis Hercílio Luz station. Also check our things to do in Florianopolis for more details. Also check our events and festivals in Florianopolis for more details. Also check our best beaches in Florianopolis for more details. Also check our where to stay in Florianopolis for more details. Also check our Florianopolis travel tips for more details.
