30YearWeather
Helsinki, September 27
Helsinki street view during September
Historical Weather Analysis

Helsinki Weather on September 27 — Best Time to Visit?

Based on 30 years of historical data, we have the answer.

cloudy

12.9°C

High

9.4°C

Low

26%

Rain

🌤️ Feels like 12°C (wind chill)

partly-cloudy-day
YES, GOOD CHOICE
Peak Season

September 27 is generally a great time to visit Helsinki. While there is a slight chance of rain (26%), showers are usually brief. Expect comfortable 13°C weather. Expect a bustling atmosphere in Helsinki right now—this is when the city truly comes alive with visitors.

Currency

EUR

Euro

Language

Finnish

+1 more

Driving

Right side

Connect

Much of Helsinki is blanketed withWi-Fi ...

Safety

Very High Safety

GPI: 1.439

Helsinki Weather Forecast for September 27

"Mild & Comfortable. Expect average highs of 12.9°C. 26% chance of rain."

What to Wear in Helsinki in September

Based on historical data for September 27, Helsinki typically experiences temperatures between 9.4°C and 12.9°C. We recommend packing light jacket, long pants to stay comfortable. With a 26% chance of rain, keeping a raincoat or umbrella handy is a smart move.

Complete Packing Guide

Weekly breakdown & essential items for Helsinki

View Guide

Smart Suitcase

  • Light Jacket
  • Long Pants

Average High

extreme-hot

12.9°C

Daytime Peak

Average Low

extreme-cold

9.4°C

Nighttime Low

Feels Like

partly-cloudy-day

12°C

🌤️ Feels accurate

Rain Chance

rain

26%

Avg 1.3mm if it rains

Cloud Cover

cloudy

68%

Overcast

Pressure

pressure

1015.6 hPa

High volatility

Helsinki Weather Conditions & UV Index

Weather Confidence

30-year variance analysis

96%Highly Predictable

Based on 10 years of data

Temperature
±1.9°CStable
Precipitation
13-39%Predictable

🎯 This date historically delivers consistent weather 96% of the time. Safe to plan outdoor activities with confidence.

Sun Exposure

UV Index & Safety Guide

1.6Low
036811+

Protection Needed

SPF 15 for extended outdoor time

Time to Sunburn

Type I-II

🔴 50 min to burn

Type III-IV

🟡 75 min to burn

Type V-VI

🟢 125 min to burn

UV estimate based on latitude, season & cloud cover. Actual UV may vary.

Outdoor Comfort

How pleasant is it outside?

58Moderate
TemperatureCool
HumidityMuggy
WindBreezy

Dew Point

9.9°C

Dry air

Heat Stress

Low

No heat warning

😐 Best outdoor time:
Any time during daylight hours

Marine Conditions

Water Temp
15.3°C
🥶 Polar Plunge
Avg daily surface temperature
Surf Conditions
0.64m
🌊 Fun Waves
Max daily wave height
Advisories

Marine Life

No special warnings. Enjoy the swim!

Swim Index

❄️ Cold Water Hazard

Travel & Logistics Insights

Local Calendar

Business Day

Standard hours in Finland

Flight Traffic

High

98/100 pressure index

Health Advisory

Required

1 vaccine • View Details →

Landing Slots

~598

Daily arrival options (inc. codeshare)

Sunrise, Sunset & Wind in Helsinki

Daylight & Sun

Solar Elevation Cycle

🌅 Sunrise

06:16

☀️ Noon

12:12

🌇 Sunset

18:08

⏱️ Daylight

11h 51m

Golden Hour
Morning06:16 - 07:12
17:13 - 18:08Evening

Wind Speed

wind

20.4 km/h

Moderate wind

Sunshine

clear-day

6.8 hrs

Direct Sun (Cloud-free)

Humidity

humidity

82%

Humid / Damp

Travel Intelligence

Exclusive flight analytics & health data for Helsinki

Smart Flight Estimator

Airport-to-Airport Logistics

unlock smart flight estimates

Add your home location in settings to see airport details.

Travel Health & Safety in Helsinki

Travel Comfort Index

Real-time tourism conditions

Weather Quality

⛅ Good

79/100

Tourist Crowds

🟡 Busy

85/100

Price Level

💰💰💰 Expensive

90/100

Health & Wellbeing

Meteo-Health Forecast

70Score
Atmospheric Pressure1015.6 hPa
Volatility:High
Migraine RiskHigh

Rapid pressure changes detected. High risk for meteosensitive people.

Joint Pain RiskLow

Weather unlikely to affect joint pain.

Fishing IndexExcellent

Fish are active due to pressure changes.

Air Quality Forecast
34AQI
Good
PM2.5 Concentration1.6 µg/m³

Air quality is excellent. Perfect for outdoor activities.

Regional Safety Profile

Stable

Seismic Activity

Zero seismic activity detected in 30 years.

Total events (30y):0
💡 No earthquake preparedness needed. Enjoy your stay!
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Helsinki on September 27 averages 12.9°C with a 26% precipitation probability. Wedding/Outdoor Event Score: 86/100."

— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology

Helsinki Weather History (2010–2024)

Temperature History

Loading chart...

Hall of Fame

Records from last 10 years

Hottest
2024
16.2°C
Coldest
2019
7°C
Rainiest
2024
30.4mm

Better Alternatives Nearby

Consider these dates within ±7 days

💡 Moving your event by a few days could significantly improve weather conditions

Compare Other Cities

Same date (September 27) in other destinations

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📍 Is Helsinki Worth Visiting on September 27?

Planning a trip to Helsinki on September 27? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year offers a bracing seasonal atmosphere averaging 12.9°C with a 26% historical precipitation risk.

✈️ Travel Logistics: Approximately 598 landing slots available daily during this period, indicating peak tourist activity.

💉 Health Advisory: 8 vaccinations are recommended for Finland, including COVID-19.

🌊 Coastal Conditions: Water temperature averages 15.3°C (polar plunge). Wave conditions are generally fun waves with heights around 0.64m.

📊 Historical Extremes: The hottest September 27 recorded in the last 30 years saw temperatures hit 16.2°C in 2024, while the coldest dropped to 7°C in 2019.

Helsinki Weather FAQ