The average daily temperature in Reykjavik during the duration of September is 5 with usual highs being around 9 with low average temperatures being 5 degrees celsius. We have put some more detail below here:
| Month | Degrees Celsius |
|---|---|
| Temperature | 5 |
| High Temperature | 9 |
| Low Temperature | 5 |
| Sunshine Per Day | 5 |
Useful Links: Reykjavik Weather: Average Weather & Yearly Climate