Normally the average weather in Siena in the course of June is 18. You can expect highs around 23 and low of 15. Our table below has the full details:
| Month | Degrees Celsius |
|---|---|
| Temperature | 18 |
| High Temperature | 23 |
| Low Temperature | 15 |
| Sunshine Per Day | 8 |
Useful Links: Siena Weather: Average Weather & Yearly Climate