You should expect the average temperature in Coutances through September is 15. Through the month the highs are about 21 with lows about 12 celsius. The table below includes more detail:
| Month | Degrees Celsius |
|---|---|
| Temperature | 15 |
| High Temperature | 21 |
| Low Temperature | 12 |
Useful Links: Coutances Weather: Average Weather & Yearly Climate