Early September 1 September
66°F
Typical afternoon high
31% historical wet-day frequency
Finland · City
Helsinki
in September.
Is September a good time?
Mild days.
A steady visitor season.
September averages 62°F afternoons and 60°F seas, with about 10 rain days. Later September is typically cooler.
- Afternoons
- 62°F
- Sea
- 60°F
- Visitor demand
- 76%of July peak
Historical Helsinki-Uusimaa regional averages, not a forecast or a measure of queues. Overnight demand compares average stays per day. Covers Helsinki and Porvoo; conditions vary within the region.
Overall match
6.5/10 · scores & prioritiesWhat matters most?
Weather 50% · Crowds 30% · Cost 20%
#5 of 12 months here · Balanced mix
Weather7.1/10Very good
CrowdsSteady all yearsimilar all year; overnight stays do not measure queues
CostPriceyfor Europe
Overall combines weather, overnight demand and cost. It does not include sea temperature.
Plan your September
What to expect.
What should I pack?
Afternoons around 62°F (16°C): light layers; nights around 47°F (9°C): a warm coat. Bring rain gear: about 10 days with at least 1 mm of rain. About 13 hours of daylight.
Can I swim in September?
The sea averages 60°F. Our swimming guide: cold: short dips, or a wetsuit. Your comfort will vary. This is open water near the coast, not a beach-specific reading.
Monthly coastal averages from NOAA, 2011–2025. Sea temperature is separate from the weather and Overall scores.
A typical day: temperatures & daylightAfternoons, nights, sea temperature & daylight Show detailsHide details
About 13 hours of daylight.
The sun rises about 06:46 and sets about 19:47 (local time, mid-month). Mornings start around 47°F (9°C); afternoons reach about 62°F (16°C). Expect rain on about 10 days in a typical September.
Typical afternoon
62°F (16°C)
average daily high, 15 recent Septembers
Night low
47°F (9°C)
average daily minimum
Sea
60°F (15°C)
cold; open water near the coast, NOAA satellite record 2011–2025
Daylight
13h 01m
on the 15th, computed from latitude
Early, middle or late?
Early or late September?
Early September is typically warmer. The afternoon high averages 66°F on the 1st, versus 56°F on the 30th.
Mid September 15 September
62°F
Typical afternoon high
36% historical wet-day frequency
Late September 30 September
56°F
Typical afternoon high
30% historical wet-day frequency
Historical daily averages from 2011–2025, smoothed over two weeks. A seasonal pattern, not a forecast. This does not establish which week has the lowest prices or fewest visitors.
Daily calendar & holiday datesSeptember 2027 · historical weather & dated holidays Show calendarHide calendar
September 2027 calendar
Weather shows historical patterns, not a forecast. Holidays and events use the dates shown for 2027.
| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|
| 166° | 266° | 366° | 466° | 565° | ||
| 665° | 765° | 865° | 964° | 1064° | 1164° | 1264° |
| 1363° | 1463° | 1562° | 1662° | 1761° | 1861° | 1960° |
| 2060° | 2159° | 2259° | 2359° | 2458° | 2558° | 2657° |
| 2757° | 2856° | 2956° | 3056° |
Afternoon high rain likely (25%+) local school holidays public holiday event
School-holiday dates for September 2027 aren't available in our data yet. A day without a school marker doesn't mean schools are open.
Afternoons cool from about 66°F (19°C) in the first week to 57°F (14°C) in the last. The chance of a wet day runs 29–37%.
Crowds, cost and getting there
Visitor season
Will it be busy?
Steady all year. September averages 76% of July's overnight stays per day. Overnight demand varies little across the year.
Overnight stays across Helsinki-Uusimaa do not measure queues, day visitors or congestion at individual sights.
Accommodation price season
Will it be cheaper?
About usual. Historical regional accommodation revenue (2024–2025 monthly average): €118 per occupied unit per night. An average, not a booking quote.
Fewer overnight stays do not automatically mean cheaper rooms. Check actual quotes for your trip.
Historical accommodation average
€118
2024–2025 monthly average; accommodation revenue per occupied unit per night; not a current booking quote. +2% vs this region's usual month.
Finland as a whole
Above EU average
2024 restaurants and hotels price level: 127 where the EU average is 100. A relative index, not a room rate.
Recorded US nonstop flights · 2024
Recorded this month
from New York JFK and Dallas; 2024 schedule, Eurostat
Statistics Finland 11ix covers hotels and other registered accommodation, including VAT. Units and coverage.
Year-to-year variation
How much does September vary?
Across the recorded years
In the 15 years from 2011 to 2025, the month's afternoons averaged between 57°F (14°C) and 66°F (19°C); in 11 of them they were within 3°F (1.5°C) of the typical 62°F (16°C). Rain days ranged from 3 to 20; half the years had 6–13.
Rain days in each September
Rain days
10
at least 1 mm, typical year; about 14 in a wet year
Mostly sunny days
3 of 30
cloud cover under 30%
Years with a 95°F+ day
0 of 15
no September in the last 15 years had a day at or above 95°F (35°C)
Good weather days
17 of 30
rated very good or better
See every recorded SeptemberHistorical monthly averages, year by year Show detailsHide details
| Year | Afternoon high | Rain days |
|---|---|---|
| 2011 | 62°F | 12 |
| 2012 | 60°F | 20 |
| 2013 | 61°F | 7 |
| 2014 | 63°F | 6 |
| 2015 | 62°F | 10 |
| 2016 | 62°F | 3 |
| 2017 | 60°F | 7 |
| 2018 | 63°F | 13 |
| 2019 | 60°F | 15 |
| 2020 | 63°F | 10 |
| 2021 | 57°F | 5 |
| 2022 | 57°F | 6 |
| 2023 | 66°F | 11 |
| 2024 | 66°F | 8 |
| 2025 | 64°F | 13 |
Checked against 13 local weather stations. How we check
Compare dates
August, September
or October?
| Typical conditions | Aug | Sep | Oct |
|---|---|---|---|
| Afternoons | 70°F | 62°F | 49°F |
| Sea | 64°F | 60°F | 52°F |
| Rain days | 11 | 10 | 11 |
| Overnight demand | 98% | 76% | 74% |
August: Warmer afternoons and warmer sea than September. August guide →
October: Cooler afternoons and cooler sea than September. October guide →
Overnight demand measures accommodation stays, not queues. Sea temperatures are monthly coastal averages.
Compare any of the 12 monthsChoose another month and compare it with September Show comparisonHide comparison
Yellow marks the top three months on the Balanced mix. September stays as your reference.
Hotel stays vary little through the year. June to August have a Weather score at least 1.0 point higher than September.
Your comparison
September or August?
Overnight stays vary little through the year.
Historical regional accommodation revenue (2024–2025 monthly average): €119 per occupied unit per night. An average, not a booking quote.
Read the August guide →| Typical conditions | September | August |
|---|---|---|
| Afternoons | 62°F | 70°F |
| Nights | 47°F | 54°F |
| Sea | 60°F | 64°F |
| Rain days | 10 | 11 |
| Visitor season | Steady all year | Steady all year |
| Overall / 10 | 6.5 | 7.4 |
| Month rank | #5 | #2 |
Every month, in detail Show detailsHide details
| Month | Overall | Rank | High | Low | Sea | Rain days | Weather | Visitor season |
|---|---|---|---|---|---|---|---|---|
| January | 3.9 | #12 | 29°F | 19°F | 36°F | 14 | 2.9 | Steady all year |
| February | 4.3 | #10 | 30°F | 20°F | 34°F | 10 | 3.3 | Steady all year |
| March | 5.3 | #8 | 37°F | 24°F | 34°F | 7 | 4.6 | Steady all year |
| April | 5.8 | #6 | 48°F | 32°F | 37°F | 7 | 5.5 | Steady all year |
| May | 6.7 | #4 | 61°F | 42°F | 45°F | 7 | 7.6 | Steady all year |
| June | 7.2 | #3 | 70°F | 51°F | 55°F | 9 | 8.7 | Steady all year |
| July | 7.5 | #1 | 73°F | 56°F | 62°F | 10 | 9.0 | Steady all year |
| August | 7.4 | #2 | 70°F | 54°F | 64°F | 11 | 8.9 | Steady all year |
| September | 6.5 | #5 | 62°F | 47°F | 60°F | 10 | 7.1 | Steady all year |
| October | 5.5 | #7 | 49°F | 38°F | 52°F | 11 | 5.0 | Steady all year |
| November | 4.8 | #9 | 41°F | 32°F | 46°F | 12 | 3.9 | Steady all year |
| December | 4.2 | #11 | 34°F | 26°F | 41°F | 14 | 3.2 | Steady all year |
Near here
Nearby places in September
Nearby regions, nearest first. Distances are centre to centre, as the crow flies; they are not road distances or journey times.
Southern Finlandabout 40 miles
Balanced Overall 5.6 · Fair weather, 61°F (16°C) · Moderate season · Cost pricey
Estoniaabout 120 miles
Balanced Overall 6.1 · Fair weather, 63°F (17°C) · Moderate season · Cost moderate
Western Finlandabout 140 miles
Balanced Overall 6.9 · Good weather, 60°F (15°C) · Moderate season · Cost pricey
ÅlandFinland · about 160 miles
Balanced Overall 5.8 · Fair weather, 61°F (16°C) · Low season · Cost pricey
Elsewhere in Europe
Better September weather than Helsinki
Helsinki's weather ranks 40 of 41 city regions this month. These city regions outside Finland have clearly better weather on your dates, nearest first, each compared with Helsinki.
Vilnius regionLithuania · about 380 miles
Very good weather (8.1): 4°F warmer afternoons, 3 fewer rain days, cheaper
CopenhagenDenmark · about 540 miles
Very good weather (8.3): 5°F warmer afternoons, 2 fewer rain days, pricier
WarsawPoland · about 580 miles
Very good weather (8.7): 7°F warmer afternoons, 2 fewer rain days, cheaper
BerlinGermany · about 690 miles
Very good weather (8.9): 9°F warmer afternoons, 2 fewer rain days
HamburgGermany · about 720 miles
Very good weather (8.6): 7°F warmer afternoons, cheaper
How we knowSources, regional scope & scoring method Show detailsHide details
The Finnish series covers hotels, cottages and other registered accommodation with at least 20 beds or electrical caravan pitches. A rental unit may be a room, a cottage or an electrical pitch. Prices include VAT. Accommodation coverage.
Hotel stays are steady all year here: this month is 76% of the busiest and about average. That counts overnight stays, not how busy the sights are.The figures cover the whole Helsinki-Uusimaa region, suburbs included. That means about 20,000 overnight visitors on a typical September night across the region, 54% of them from Finland itself. Rentals booked through Airbnb, Booking, Expedia and Tripadvisor add up to 3,400 more: 17 for every 100 counted above. Some are the same properties counted twice.
| Climate suitability (HCI:Urban, 0–100) | 71 |
| How our weather was checked | 13 open weather stations in this region, January and July: afternoon highs typically within 1°F (0.3°C), night lows within 1°F (0.7°C). |
| Tourist nights per 1,000 residents per day | 11 |
| Busiest month here | July · 15 |
| Visitors as share of people present | 1.1% |
| Rank among Europe's regions this month | 33rd percentile |
| Domestic share of nights | 54% |
| Platform rental nights per 100 counted nights | 17 |
| Visitor share if every platform night were extra | 1.3% |
| Population used | 1.8 million |
| Statistical region | FI1B · Helsinki-Uusimaa |
Crowds: Eurostat nights spent at tourist accommodation, by month and NUTS 2 region, 2024–2025 average. Overnight visitors per night is the month's nights divided by its days; the per-1,000 figure is Eurostat's, against each year's population. Platform rentals: Eurostat nights booked via Airbnb, Booking, Expedia and Tripadvisor, 2024–2025 average, shown separately because some properties are in both counts. Weather: Holiday Climate Index computed from ERA5 reanalysis with daily highs, night lows and rain days corrected from open national weather-service station records, 2011–2025, population-weighted to the region; day-by-day figures are the same data averaged by date. Heat and rain odds are counted across those years. Sunrise and sunset: NOAA solar equations, local time. Prices: Eurostat price level index and HICP, national; the first figure is regional (Statistics Finland, StatFin 11ix: average room price per occupied room (incl. VAT)). Full method · this region's data.