Reykjavik Weather in September
Iceland · Subarctic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Reykjavik sees average temperatures ranging from a low of 5.6°C (42.1°F) to a high of 9.9°C (49.8°F), with a mean of 7.8°C (46.0°F). Compared to the annual average of 4.5°C (40.1°F), this month is 3.3°C warmer than the yearly norm. Precipitation averages 140.1mm, making it approximately 10.0mm wetter than the monthly average of 130.0mm. The city receives an average of 5.9 hours of sunshine per day during September, with relative humidity averaging 82.8%. Wind speeds reach an average maximum of 22.3 km/h. Snowfall averages 1.2cm during September, which can affect travel plans and outdoor activities. For travelers, this month offers a temperature experience in Reykjavik, with wetter-than-average conditions compared to the rest of the year.
Planning around Reykjavik's daylight is more important than temperature. I was there in June and the midnight sun meant I could hike at 11pm — disorienting but incredible. December gives you about 4 hours of daylight, which limits outdoor plans severely. The data shows mild temperatures for the latitude (rarely below -5°C thanks to the Gulf Stream), but wind chill is the real factor. Pack windproof everything, regardless of season.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 10.8°C (51.4°F) | 7.8°C (46.0°F) | 4.4°C (39.9°F) |
| Rainfall | 128.4mm | 140.1mm | 134.3mm |
| Sunshine | 7.6 hrs | 5.9 hrs | 4.5 hrs |
| Humidity | 83.9% | 82.8% | 83.0% |
| Wind | 18.8 km/h | 22.3 km/h | 21.7 km/h |
| Rainy Days | 20.6 | 21.8 | 20.6 |
| Snowfall | 0.0 cm | 1.2 cm | 8.5 cm |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Reykjavik in September, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Reykjavik in September?
The average temperature in Reykjavik during September ranges from 5.6°C (42.1°F) to 9.9°C (49.8°F), with a mean of 7.8°C (46.0°F).
How much does it rain in Reykjavik in September?
Reykjavik receives an average of 140.1mm of precipitation in September, spread across approximately 21.8 rainy days.
What should I pack for Reykjavik in September?
Based on September weather data, pack warm layers, a medium jacket, and waterproof outerwear. Rain gear is essential — this month averages 140.1mm of precipitation.
Is September a good time to visit Reykjavik?
September is a cooler month, suitable for travelers who prefer mild weather and fewer crowds. Pack warm layers and enjoy indoor attractions.
Other Months for Reykjavik
Cities with Similar September Climate (Subarctic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 64.15°, -21.94°. Timezone: Atlantic/Reykjavik. Last updated: 2026-07-30.