Oslo Weather in September
In September, Oslo averages a high of 16°C (61°F) and a low of 8°C (47°F), from 55 years of daily records (1971–2026).
16°C
Average high
61°F
8°C
Average low
47°F
27°C
Record high
81°F · September 6, 2024
-2°C
Record low
28°F · September 27, 1990
What September Is Like in Oslo
- Oslo's hottest September day on record is a recent one: 27°C (81°F) on September 6, 2024.
- September in Oslo has become 2.2°C (3.9°F) warmer on average: the 2011–2025 average against 1970–1989.
- 6 of the 10 warmest Septembers on record in Oslo have come since 2011.
- The coldest September reading, -2°C (28°F) on September 27, 1990, has not been matched in 36 years.
At least 1 mm of rain falls on 33% of September days, and the month averages 84 mm in total.
Warmest: 2016 (19.4°C)Latest: 2025 (17.5°C)10-year averageLong-run average (15.9°C)
Look Up a Day in September
See the weather in Oslo on any September date, year by year.
Source: NOAA GHCN-Daily, Oslo Blindern (1971–2026). Averages cover 1971–2026. How we compute this