Weather in Sundsvall in September 2025
Average weather
Average temperature in Sundsvall in September
The expected average maximum temperature in September is +17°C with a maximum of +24°C and a minimum of +2°C.
The average maximum temperature goes down 27% by the end of the month, compared with the beginning of the month, from +19°C to +13°C.
Is Sundsvall warm or cold in September?
Sundsvall is typically mild in September.
Maximum temperatures go down compared to the previous month from +19°C to +14°C. The minimum temperature also goes down from +11°C to +7°C.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how September is compared to other months in Sundsvall:
Climate in Sundsvall in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +19°C | +14°C | +8°C | ||||
| Min. temperature | ||||||
| +3°C | -2°C | -15°C | ||||
| Max. temperature | ||||||
| +30°C | +25°C | +20°C | ||||
| Rainfall | ||||||
| 80 mm | 59 mm | 52 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 77% | 81% | 84% | ||||
| Air pressure | ||||||
| 1010 HPa | 1011 HPa | 1010 HPa | ||||
| Sunny days | ||||||
| 4 | 4 | 5 | ||||
| Cloudy days | ||||||
| 9 | 10 | 11 | ||||
| Rainy days | ||||||
| 17 | 15 | 13 | ||||
| Snowy days | ||||||
| 0 | 0 | 2 | ||||
September weather is still as ok as in August. It’s getting colder in September. From +19°C in the day, the average maximum temperature lowers to +14°C. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 80 mm to 59 mm. Humidity rises from 77% to 81%. The average wind speed doesn’t change much during September, staying around 2 m/s. The amount of sunny days stay about the same, averaging 4 sunny days during the month.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 3 m/s getting up to 5 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Sundsvall is gradually increasing during September, going from 3 m/s to 3 m/s over the course of the month.
Rain
How was the weather last September in Sundsvall?
Climate Change over Years
The climate in Sundsvall in September has not changed much over the last 43 years.
The average temperature was the lowest in 1985 (+6°C) and the highest in 2020 (+10°C). The driest year was 1997 with only 281 mm of rainfall, and the wettest year was 2000 with 645 mm.
FAQ
Is September a good time to visit Sundsvall?
Can you sunbathe in Sundsvall in September?
Is Sundsvall rainy in September?
Is it sunny in Sundsvall in September?
Other cities in Sweden
Monthly weather in Sundsvall
Source of the data
For this page, we’ve looked at the typical weather in Sundsvall, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.