Month by month
| Month | Afternoon | Sea | Rain | Verdict |
|---|---|---|---|---|
| January | 5.4 °C | — | 13 days | Unfavourable season |
| February | 7.8 °C | — | 10 days | Unfavourable season |
| March | 11.3 °C | — | 11 days | Unfavourable season |
| April | 15.4 °C | — | 11 days | Possible, with trade-offs |
| May | 19.8 °C | — | 11 days | Pleasant — a good time to go |
| June | 24.9 °C | — | 10 days | Ideal — one of the best times of year |
| July | 26.3 °C | — | 10 days | Ideal — one of the best times of year |
| August | 26.3 °C | — | 10 days | Ideal — one of the best times of year |
| September | 21.6 °C | — | 9 days | Pleasant — a good time to go |
| October | 15.7 °C | — | 11 days | Possible, with trade-offs |
| November | 9.4 °C | — | 13 days | Unfavourable season |
| December | 6.6 °C | — | 13 days | Unfavourable season |
Before you go
Three things to check once you have picked your dates.
Entry
Germany is in the European Union. Entry rules depend on your nationality — check before booking.
Safety
No specific restrictions
Usual precautions apply.
Official advice updated 11 August 2026
Health
Recommended vaccinations, water quality, mosquitoes: advice depends on the country and the season. Some vaccines need time before departure.
Beau Fixe is not a safety or health authority. These notes summarise public advisories and link to their source; only the competent authorities are authoritative. Alert levels: Foreign, Commonwealth & Development Office (gov.uk), Open Government Licence v3.0.
FAQ
Can you swim in Mainz in January?
Mainz is not a seaside destination (no sea data).
How hot is Mainz in January?
Expect 5.4°C in the afternoon and 0.3°C at night, averaged over the last 10 years.
Does it rain a lot in Mainz in January?
Around 13 days with rain (≥ 1 mm) in the month — 43% of days.