Monte Carlo Weather in September

During September, Monte Carlo experiences high daytime temperatures of 23°C (73°F) and cooler nights around 18°C (64°F). Expect quite a bit of rainfall. Around 76 mm (3 in) is typical.

Rainfall in Monte Carlo in September

Expect around 7 days of rain based on historical data, with 76 mm (3 in) average. Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.

Temperature in Monte Carlo in September

September tends to be one of the perfect months in Monte Carlo, with 23°C (73°F) in the afternoon and 18°C (64°F) overnight. The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. At 18°C (64°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.

Sunshine in Monte Carlo in September

There are approximately 242 hours of sunshine this month, resulting in mostly clear days.

Average water temperature in September

With water at 22°C (72°F), you can expect warm, pleasant conditions for any water activity. There's no adjustment period — it feels comfortable straight away.

If you're inclined towards comfortable temperatures and drier conditions, September is a good time to visit Monte Carlo.

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• January
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• May
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• October
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For a detailed overview over the year and the best time to visit Monaco, check out our Monte Carlo's climate page.

Monte Carlo Temperature in September

Min Temperature 18°C (64°F)  

Max Temperature 23°C (73°F)  

Water Temperature 22°C (72°F)  

Chance of Rain 25%  

Precipitation 76 mm (3 in)  

Rainy days 7 days  

Sunshine 242 hours  

Percentage Sunshine 67%  

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Monte Carlo typically stay consistent throughout September, with daily highs averaging around 23°C (73°F). Nights are pleasant, with lows typically ranging from 16°C (61°F) to 19°C (66°F).

Average temperatures in September

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Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in September

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Historical weather for Monte Carlo in September

Browse day-by-day weather records for Monte Carlo spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Historical weather Temperatures Precipitation

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Monte Carlo historical weather extremes in September

Based on weather observations in Monte Carlo between 1976 and 2025, these are the recorded extremes during September.

• The hottest September day on record in Monte Carlo reached 33°C (91°F) (September 4, 2009).
• On September 25, 2025, Monte Carlo saw its coldest September day with temperatures maxing out at 14°C (57°F).
• Nighttime temperatures dropped to 7°C (45°F) on September 25, 2025, marking the coldest September night on record.

What to Wear in Monte Carlo in September

For Monte Carlo in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. Rain is likely on several days, so bring a good rain jacket. The water temperature sits at about 22°C (72°F), making it perfect for swimming and water activities. Don't forget to pack your favorite swimwear and perhaps some snorkel gear. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Monte Carlo in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Cycling

9/10

Walking

9/10

Barbeque

8/10

Camping

8/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Monaco, check out our Monte Carlo's climate page.

More climate data for Monte Carlo

Temperature Rainfall Sunshine Water Temp

See the full Monte Carlo climate overview or explore weather in Monaco.