Climate averages 1991–2020
Vantaa weather
in September.
A cool, moderately wet month: the 4th warmest and the 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a cool month in Vantaa: daytime highs average 14.9°C and nights cool to about 9.0°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 57 mm of rain on roughly 10 days, which makes September a moderately wet month (the 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 58 min on an average September day.
The nearest other city in this atlas is Helsinki (15 km away). In September its highs average 14.6°C, about as warm as Vantaa, with 57 mm of rain.
Among the 13 cities listed in Finland, Vantaa ranks 2nd of 13 for the warmest September highs and joint 8th of 13 for the driest September (rainfall, lowest first). The mean September high of those 13 cities is 13.8°C; Vantaa is 1.1°C warmer than that mean.
From September to October, average highs fall by 6.8°C to 8.1°C, and monthly rainfall rises from 57 mm to 59 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Vantaa climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -2.3°C-6.7°C | -6.7°C | 48 | 10.9 | 6.77 h |
| February | -2.8°C-7.7°C | -7.7°C | 41 | 9.3 | 9.09 h |
| March | 1.2°C-5.1°C | -5.1°C | 37 | 8.5 | 11.712 h |
| April | 8.1°C0.0°C | 0.0°C | 37 | 8.7 | 14.615 h |
| May | 14.8°C5.9°C | 5.9°C | 44 | 8.9 | 17.217 h |
| June | 19.0°C10.9°C | 10.9°C | 72 | 11.7 | 18.819 h |
| July | 21.9°C14.2°C | 14.2°C | 76 | 11.9 | 18.118 h |
| August | 20.3°C13.3°C | 13.3°C | 76 | 12.3 | 15.716 h |
| September, selected | 14.9°C9.0°C | 9.0°C | 57 | 10.4 | 13.013 h |
| October | 8.1°C3.7°C | 3.7°C | 59 | 11.1 | 10.210 h |
| November | 3.0°C-0.4°C | -0.4°C | 59 | 11.5 | 7.68 h |
| December | -0.2°C-4.1°C | -4.1°C | 55 | 12.2 | 6.06 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Helsinki in SeptemberFinland · 15 kmHigh 14.6°C · Low 9.8°C · 57 mm rain
- Espoo in SeptemberFinland · 24 kmHigh 14.5°C · Low 10.0°C · 55 mm rain
- Lahti in SeptemberFinland · 84 kmHigh 14.1°C · Low 8.5°C · 51 mm rain
- Tallinn in SeptemberEstonia · 97 kmHigh 15.3°C · Low 9.9°C · 60 mm rain
- Kouvola in SeptemberFinland · 111 kmHigh 14.2°C · Low 8.4°C · 53 mm rain
- Tampere in SeptemberFinland · 150 kmHigh 13.5°C · Low 8.8°C · 53 mm rain
- Turku in SeptemberFinland · 153 kmHigh 15.0°C · Low 8.8°C · 58 mm rain
- Lappeenranta in SeptemberFinland · 191 kmHigh 13.9°C · Low 8.6°C · 56 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Vantaa) is explained once on the Vantaa year overview and on the Sources, method and limits page.
Helsinki lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.