What is the weather like in Helsinki in September?

Expect temperatures between 11°C and 15°C with 25% average rain probability and about 8 hours of sunshine daily.

What is the weather like in Helsinki in September?

Helsinki in September scores 63/100 based on 30 years of climate data. Good option with minor considerations.

Who should visit Helsinki in September?

September in Helsinki is ideal for: Cultural tourists, Business travelers.

Helsinki Weather in September | 30-Year Forecast

Avg High

15°C

Hottest around day 5

Avg Low

11°C

Coolest around day 30

Rainy Days

10days

25% avg rain chance

Sunshine

8hrs/day

Autumn season

Sea Temperature in September

Gulf of Finland(Suomenlahti)

16.9°C

Monthly Average

Water Feel

💧Refreshing

Consider a wetsuit for extended swimming

Swim Rating

🏄Cool, wetsuits recommended

Based on average sea surface temperature

Body of Water

Gulf of Finland

Suomenlahti

Helsinki coastline

Essential Travel Info for Helsinki

🗓️ Best Time to Visit 📖 Travel Guide 🍴 Food Guide

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

Travel Intelligence

Exclusive flight analytics & health data for Helsinki

Smart Flight Estimator

Airport-to-Airport Logistics

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Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Major Hub

81/ 100

Traffic Index

Extremely busy airport

Peak Daily Arrivals

slots per day

Peak

Jun

Low

Aug

Monthly Traffic Distribution

204

Jan

202

Feb

194

Mar

226

Apr

232

May

613

Jun

600

Jul

176

Aug

598

Sep

542

Oct

502

Nov

579

Dec

Traffic Level

Low Season

Key Connections

Stockholm -Arlanda (ARN)

Rovaniemi (RVN)

Copenhagen Kastrup (CPH)

Oulu / Oulunsalo Oulu (OUL)

Tallinn Lennart Meri (TLL)

Health & Safety Advisory

CDC travel health recommendations

8 Recommendations

COVID-19

All eligible travelers should be up to date with their COVID-19 vaccines. Please seeYour COVID-19 Vaccinationfor more information.

Hepatitis A

Consider hepatitis A vaccination for most travelers. It is recommended for travelers who will be doing higher risk activities, such as visiting smaller cities, villages, or rural areas where a traveler might get infected through food or water. It is recommended for travelers who plan on eating street food.

Hepatitis B

Recommended for unvaccinated travelers younger than 60 years old traveling to Finland. Unvaccinated travelers 60 years and older may get vaccinated before traveling to Finland.

Measles

Cases of measles are on the rise worldwide. Travelers are at risk of measles if they have not been fully vaccinated at least two weeks prior to departure, or have not had measles in the past, and travel internationally to areas where measles is spreading.All international travelers should be fully vaccinated against measles with the measles-mumps-rubella (MMR) vaccine, including an early dose for infants 6–11 months, according toCDC’s measles vaccination recommendations for international travel.

Polio

In Finland poliovirus has been identified in the past year.Travelers to Finland are at increased risk of exposure to poliovirus.Vaccine recommendations: Adults traveling to Finland who received a complete polio vaccination series as children may receive a single lifetime booster dose of inactivated polio vaccine; travelers who are unvaccinated or not fully vaccinated should receive a complete polio vaccination series before travel. Children who are not fully vaccinated will be considered for anaccelerated vaccination schedule.

Rabies

Dogs infected with rabies are not commonly found in Finland.If rabies exposures occur while in Finland, rabies vaccines are typically available throughout most of the country.Rabies pre-exposure vaccination considerations include whether travelers 1) will be performing occupational or recreational activities that increase risk for exposure to potentially rabid animals and 2) might have difficulty getting prompt access to safe post-exposure prophylaxis.Please consult with a healthcare provider to determine whether you should receive pre-exposure vaccination before travel.For more information, seecountry rabies status assessments.

+2 more

Source: CDC Travelers' Health

View Complete Health Guide

Is September a Good Time to Visit Helsinki?

👌Good option with minor considerations(63/100)

Short Answer

September is Helsinki's peak season for good reason: 15°C temperatures and 25% rain probability. But expect crowds (98% of annual maximum) and premium prices.

Decision Factors

Vaccinations required

Yellow Fever

Very high humidity

81% average humidity

Peak tourist season

98% of annual peak - expect crowds and peak prices

Health precautions needed

Be aware of: Leptospirosis, Hantavirus, Parvovirus B19

Plenty of sunshine

8.1h of sunshine daily

Calm, family-friendly seas

0.48m wave height - Fun Waves

Good For

🏛️
Cultural tourists
Comfortable conditions for exploring museums and sites
💼
Business travelers
Climate-controlled meetings unaffected by weather

Who Should Avoid

🏖️
Beach lovers
Sea temperature only 16.9°C - too cold for comfortable swimming
💰
Budget travelers
Peak season means premium prices everywhere
👴
Elderly travelers
81% humidity creates difficult conditions

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,Helsinki in September averages 15°C with 25% precipitation probability."

📊 Source: 30YearWeather.com🛰️ Data: NASA POWER (1991-2021)View Methodology →

Frequently Asked Questions: Helsinki in September

What are the temperatures in Helsinki in September?

Daytime highs average 15°C, nights drop to 11°C. Temperatures remain fairly consistent.

How many rainy days in Helsinki in September?

Expect around 10 days with measurable rainfall. Rain is unlikely to disrupt plans.

What to wear in Helsinki in September?

Layers are key. A medium-weight jacket and closed-toe shoes.

Is September peak season in Helsinki?

This is shoulder season—moderate prices and manageable crowds.

Helsinki Weather in September