Average temperatures in Guernsey in September is 14 with a typical high being 18 with low average temperatures being 13. See our table below for a full breakdown:
| Month | Degrees Celsius |
|---|---|
| Temperature | 14 |
| High Temperature | 18 |
| Low Temperature | 13 |
| Sunshine Per Day | 7 |
Useful Links: Guernsey Weather: Average Weather & Yearly Climate