30YearWeather
Helsinki, December 20
Helsinki street view during December
Historical Weather Analysis

Helsinki Weather on December 20 — Best Time to Visit?

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

cloudy

0.6°C

High

-3°C

Low

24%

Rain

🥶 Feels like -4.9°C (wind chill)

partly-cloudy-day
YES, GOOD CHOICE
Peak Season

December 20 is generally a great time to visit Helsinki. While there is a slight chance of rain (24%), showers are usually brief. Expect comfortable 1°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 December 20

"Cold & Crisp. Expect average highs of 0.6°C. 24% chance of snow."

What to Wear in Helsinki in December

Based on historical data for December 20, Helsinki typically experiences temperatures between -3°C and 0.6°C. We recommend packing heavy coat, scarf, gloves to stay comfortable. Trends suggest it will stay mostly dry (24% rain probability), but checking the forecast before heading out is always wise.

Complete Packing Guide

Weekly breakdown & essential items for Helsinki

View Guide

Smart Suitcase

  • Heavy Coat
  • Scarf
  • Gloves

Average High

extreme-hot

0.6°C

Daytime Peak

Average Low

extreme-cold

-3°C

Nighttime Low

Feels Like

partly-cloudy-day

-4.9°C

🥶 Wind chill effect

Snow Chance

snow

24%

Avg 1.3mm if it snows

Snowfall

snow

0.8 cm

~24% chance

Pressure

pressure

1007.7 hPa

High volatility

Helsinki Weather Conditions & UV Index

Weather Confidence

30-year variance analysis

82%Highly Predictable

Based on 10 years of data

Temperature
±3.3°CModerate
Precipitation
12-50%Moderate

🎯 This date historically delivers consistent weather 82% of the time. Safe to plan outdoor activities with confidence.

Sun Exposure

UV Index & Safety Guide

0Low
036811+

Protection Needed

SPF 15 for extended outdoor time

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

Outdoor Comfort

How pleasant is it outside?

22Uncomfortable
TemperatureCold
HumidityMuggy
WindBreezy

Dew Point

-1.3°C

Dry air

Heat Stress

Low

No heat warning

😣 Best outdoor time:
Midday (11 AM - 3 PM) when warmest

Marine Conditions

Water Temp
0.7°C
🥶 Polar Plunge
Avg daily surface temperature
Surf Conditions
0.73m
🌊 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

94/100 pressure index

Health Advisory

Required

1 vaccine • View Details →

Landing Slots

~579

Daily arrival options (inc. codeshare)

Sunrise, Sunset & Wind in Helsinki

Daylight & Sun

Solar Elevation Cycle

🌅 Sunrise

09:24

☀️ Noon

12:18

🌇 Sunset

15:13

⏱️ Daylight

5h 49m

Golden Hour
Morning09:24 - 11:38
12:59 - 15:13Evening

Wind Speed

wind

22.7 km/h

Moderate wind

Sunshine

clear-day

0.9 hrs

Direct Sun (Cloud-free)

Humidity

humidity

87%

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

☀️ Excellent

81/100

Tourist Crowds

🟡 Busy

80/100

Price Level

💰💰💰 Expensive

95/100

Health & Wellbeing

Meteo-Health Forecast

40Score
Atmospheric Pressure1007.7 hPa
Volatility:High
Migraine RiskHigh

Rapid pressure changes detected. High risk for meteosensitive people.

Joint Pain RiskHigh

Low pressure & humidity may aggravate joints.

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 December 20 averages 0.6°C with a 24% precipitation probability. Wedding/Outdoor Event Score: 12/100."

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

Helsinki Weather History (2010–2024)

Temperature History

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Hall of Fame

Records from last 10 years

Hottest
2015
9.1°C
Coldest
2021
-9.2°C
Rainiest
2022
5.5mm

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 (December 20) in other destinations

🌍 Explore the same date in different destinations around the world

📍 Is Helsinki Worth Visiting on December 20?

Planning a trip to Helsinki on December 20? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year offers a bracing seasonal atmosphere averaging 0.6°C with a 24% historical precipitation risk.

✈️ Travel Logistics: Approximately 579 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 0.7°C (polar plunge). Wave conditions are generally fun waves with heights around 0.73m.

📊 Historical Extremes: The hottest December 20 recorded in the last 30 years saw temperatures hit 9.1°C in 2015, while the coldest dropped to -9.2°C in 2021.

Helsinki Weather FAQ