Climate averages 1991–2020
Lillestrøm weather
in September.
A mild, moderately wet month: the 5th warmest and the 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Lillestrøm: daytime highs average 15.0°C and nights cool to about 8.6°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 81 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 57 min on an average September day.
The nearest other city in this atlas is Oslo (18 km away). In September its highs average 15.5°C, 0.5°C warmer than Lillestrøm, with 89 mm of rain.
Among the 8 cities listed in Norway, Lillestrøm ranks 5th of 8 for the warmest September highs and joint 1st of 8 for the driest September (rainfall, lowest first). The mean September high of those 8 cities is 15.0°C; Lillestrøm is level with that mean.
From September to October, average highs fall by 6.5°C to 8.5°C, and monthly rainfall rises from 81 mm to 84 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
Lillestrøm climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -2.0°C-6.9°C | -6.9°C | 65 | 10.4 | 6.87 h |
| February | -0.7°C-6.5°C | -6.5°C | 49 | 8.3 | 9.19 h |
| March | 3.6°C-3.5°C | -3.5°C | 49 | 8.0 | 11.812 h |
| April | 9.4°C0.7°C | 0.7°C | 53 | 9.0 | 14.515 h |
| May | 15.1°C5.8°C | 5.8°C | 74 | 11.5 | 17.117 h |
| June | 18.8°C10.2°C | 10.2°C | 91 | 11.9 | 18.719 h |
| July | 21.0°C13.0°C | 13.0°C | 94 | 12.6 | 18.018 h |
| August | 19.6°C12.3°C | 12.3°C | 104 | 13.5 | 15.616 h |
| September, selected | 15.0°C8.6°C | 8.6°C | 81 | 10.4 | 13.013 h |
| October | 8.5°C3.8°C | 3.8°C | 84 | 11.4 | 10.210 h |
| November | 3.3°C-0.3°C | -0.3°C | 84 | 11.6 | 7.68 h |
| December | -0.7°C-5.0°C | -5.0°C | 66 | 10.8 | 6.16 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
- Oslo in SeptemberNorway · 18 kmHigh 15.5°C · Low 9.5°C · 89 mm rain
- Drammen in SeptemberNorway · 53 kmHigh 15.8°C · Low 9.7°C · 94 mm rain
- Fredrikstad in SeptemberNorway · 82 kmHigh 15.6°C · Low 10.6°C · 81 mm rain
- Örebro in SeptemberSweden · 246 kmHigh 15.6°C · Low 9.4°C · 55 mm rain
- Gothenburg in SeptemberSweden · 256 kmHigh 16.2°C · Low 10.6°C · 93 mm rain
- Kristiansand in SeptemberNorway · 266 kmHigh 15.4°C · Low 10.7°C · 127 mm rain
- Borås in SeptemberSweden · 271 kmHigh 15.5°C · Low 9.7°C · 83 mm rain
- Jönköping in SeptemberSweden · 301 kmHigh 15.6°C · Low 10.2°C · 62 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 Lillestrøm) is explained once on the Lillestrøm year overview and on the Sources, method and limits page.