Monaco weather through the year, with the official figures alongside

Search for Monaco weather and you’ll get two things, a five-day forecast and the same table of averages copied from site to site. I’m giving you the table too, because it’s handy for packing, but I’m putting it next to what Monaco has actually measured in recent years, which is a good deal livelier than the averages suggest. This page doesn’t choose your dates for you. That’s the job of the best time to visit Monaco, which weighs the weather against the races and closures.

What is the weather like in Monaco?

It’s a textbook Mediterranean climate. In the 1981-2010 averages that English Wikipedia carries from Météo-France, highs go from 13 °C in January and February to 26.9 °C in August, and lows barely drop below 7.4 °C even in midwinter. The annual mean comes out at 16.4 °C, and the Société des Bains de Mer, the company behind the Casino, talks of around 16 °C, which fits.

I want to be straight about that table. It’s a secondary source, because IMSEE, Monaco’s statistics office, only publishes its official 1991-2020 normal as a chart with no month-by-month figures. So I use it to compare one month with another, not to promise you that May will be exactly 20.4 °C.

What the official thermometer says

IMSEE takes temperature and rainfall at the Exotic Garden weather station, and sunshine and wind at the Oceanographic Museum. Its latest report, for 2025, is more useful to me than any average. The mean temperature that year was 18.1 °C, 1.3 °C above the 1991-2020 normal of 16.8 °C, which made it the second warmest year since records began in 1969, behind only 2022.

The decades are what strike me most. From 1991 to 2000 the mean was 16.4 °C, from 2011 to 2020 it rose to 17.2 °C, and for 2021 to 2025 it’s already 17.9 °C. According to IMSEE, every decade since the 1970s has been warmer than the one before. If you’re reading an older table, allow for a bit more heat than it shows.

Summers hotter than the averages admit

In the table, July and August sit at around 26.6 °C and 26.9 °C for average highs, with lows of 21 °C. Recent summers have added spikes on top. June 2025 was the hottest June ever measured in Monaco, with a mean of 24.8 °C, and that summer brought two heatwaves, from 28 June to 4 July and from 9 to 17 August. During the second, on 16 August, the station hit 35.7 °C, an all-time record that beat the one set in August 2024. For comparison, the region’s own heatwave threshold is three days in a row above 31 °C by day and not below 24 °C at night.

That changes how I’d plan a summer day. I’d do the Rock and the gardens first thing, keep the middle of the day for shade or the water, and spend the evening by the harbour. For the climbs, the buses and public lifts I cover in getting around Monaco are more than a comfort in August.

Sunshine is another surprise. 2025 was a dull year by Monaco’s standards, with 1,953 hours against an average of 2,456 for 2022 to 2024, and in July and August direct sunlight fell by more than 60% on the usual level. The 329 hours of July sunshine in the table are an average, not a promise.

How warm is the sea in Monaco?

For swimming I use the Weather Atlas figures. The water is about 13 °C in January and February, reaches 18 °C in May, passes 21 °C in June and peaks in August at 23.6 °C. It’s still 22.2 °C in September and drops to 19.6 °C in October. The Société des Bains de Mer gives slightly higher figures for high summer, 24 to 26 °C. That’s why my ranking above orders the months by water temperature alone, and you’ll find where to get in on Monaco’s beaches.

Rain and wind, the bits the postcards leave out

Rain falls mostly in autumn. In the averages October has 128.7 mm and November 103.2 mm, while July manages just 13.7 mm. Real years swing wildly, though. IMSEE counted 436.4 mm in 2023, 1,016.1 mm in 2024 and 644.1 mm in 2025, the last one 23% below normal yet spread over 67 rain days, four more than usual. In 2025 the wettest months were January and March, at around 130 mm each, and October came in well short of normal.

Wind matters too. In 2025 there were 34 days with gusts of 60 km/h or more, and the strongest, 95.8 km/h, was recorded on 21 March by the Oceanographic Museum. If rain or wind spoils a day, the covered visit I’d pick is the Oceanographic Museum itself.

What to pack, season by season

From December to February, a light coat and layers, because lows sit around 7 or 8 °C. From March to May, a thin jacket and something for April showers, with 7.3 rain days on average. From June to September, summer clothes, sun cream and a hat, on the basis that heatwaves are now part of a Monaco summer. For October and November, a jacket and a folding umbrella. And all year round, comfortable shoes, because in Monaco you walk uphill. What’s on in town each month, from festivals to races, is in events in Monaco.