Normally the weather in Formia in the course of December is 8. Highs are around 14 degrees with a low of 6.
| Month | Degrees Celsius |
|---|---|
| Temperature | 8 |
| High Temperature | 14 |
| Low Temperature | 6 |
| Sunshine Per Day | 4 |
Useful Links: Formia Weather: Average Weather & Yearly Climate