Seinäjoki
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Seinäjoki Weather in September

Seinäjoki in September sees moderate daytime temperatures of 15°C (59°F) and nighttime lows of 6°C (43°F). Moderate rainfall is typical, with around 60 mm (2.4 in) for the month.

Rainfall in Seinäjoki in September

Rain is expected on roughly 17 days, totalling around 60 mm (2.4 in) for the month. Expect plenty of grey, overcast days rather than intense storms. The rain rarely amounts to much on any given day.

Temperature in Seinäjoki in September

September in Seinäjoki brings typical temperatures with highs around 15°C (59°F) and lows of 6°C (43°F). Temperatures can feel cooler in the morning and evening, so layering is often the best approach. Nights fall to 6°C (43°F), which is cold enough to feel it indoors too. A good thick duvet makes all the difference for a comfortable night's sleep.

Sunshine in Seinäjoki in September

You can expect a moderate amount of sunlight, with approximately 135 hours. This means a pleasant mix of sun and overcast.

Should you favor a climate that's both dry and comfortably warm, June, July and August typically offer the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

Seinäjoki Temperature in September

Min Temperature
6°C (43°F)
Max Temperature
15°C (59°F)
Chance of Rain
55%
Precipitation
60 mm (2.4 in)
Rainy days
17 days
Sunshine
135 hours *
Percentage Sunshine
*
* Data from: Vaasa, Finland (70 KM, 43 Miles).

Seinäjoki Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in Seinäjoki - and find the best time to visit.

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Seinäjoki typically drop from around 16°C (61°F) at the start of September to approximately 11°C (52°F) by the end. Nights are cold, with lows typically ranging from 3°C (37°F) to 8°C (46°F).

Average temperatures in September

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

Historical weather records for Seinäjoki in September

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

Seinäjoki historical weather extremes in September

Based on 50 years of weather observations (1976-2026), these are the most extreme conditions recorded in Seinäjoki.

  • The hottest September day on record in Seinäjoki reached 26°C (79°F) (September 5, 2024).
  • The coldest September day was on September 30, 1997, with a maximum of 1°C (34°F).
  • Seinäjoki registered its coldest September night on September 28, 1986, with temperatures dropping to -7°C (19°F).
  • The wettest day in September Seinäjoki was on September 18, 2015 with 31 mm (1.2 in) of precipitation.

Best Places in Finland in September

Find out more about the weather in Finland and which places have the best travel conditions in this month. See all of Finland in September →

perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

What to Wear in Seinäjoki in September

The weather can swing between comfortable and chilly in September, so flexibility is key. Pack a variety of tops, at least one warm layer, and both shorts and long pants. This gives you options no matter what the day brings. Wet weather is likely, so pack waterproof gear for multiple rainy days. Sunglasses could come in handy during the sunnier parts of your trip.

What To Do in Seinäjoki in September

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

  • Swimming
    5/10
  • Cycling
    6/10
  • Walking
    6/10
  • Camping
    4/10
  • Outdoor sports
    10/10

Seinäjoki 3-Day Forecast

More climate data for Seinäjoki

Popular in September

Where to go in September - average daytime high across popular destinations.

Bucket list

Need travel inspiration? Check out our bucket list articles and be inspired.