Reykjavik Weather in September
In September, Reykjavik averages a high of 11°C (51°F) and a low of 6°C (42°F), from 55 years of daily records (1971–2026).
11°C
Average high
51°F
6°C
Average low
42°F
18°C
Record high
65°F · September 11, 1971
-4°C
Record low
24°F · September 24, 1974
What September Is Like in Reykjavik
- The September heat record, 18°C (65°F) on September 11, 1971, has stood for 55 years.
- 5 of the 10 warmest Septembers on record in Reykjavik have come since 2011.
- The coldest September reading, -4°C (24°F) on September 24, 1974, has not been matched in 52 years.
- September in Reykjavik has become 1.2°C (2.2°F) warmer on average: the 2011–2025 average against 1970–1989.
At least 1 mm of rain falls on 45% of September days, and the month averages 76 mm in total.
Warmest: 2006 (13.4°C)Latest: 2025 (12.8°C)10-year averageLong-run average (10.7°C)
Look Up a Day in September
See the weather in Reykjavik on any September date, year by year.
Source: NOAA GHCN-Daily, Reykjavik (1971–2026); Reykjavik (2006–2025). Averages cover 1971–2026. How we compute this