Month-specific sea-surface temperature · Slovenia

Piran Sea Temperature in October

20.7°C

69.3°F

In October, sea-surface temperature near Piran has a historical monthly average of 20.7°C. This is not the reading for any particular holiday date.

Across 2023–2025, the lowest and highest yearly October monthly means were 20.1–21.8°C. These are not daily extremes.

Previous month

September · 24.1°C

Change into October: -3.4°C

Next month

November · 17.4°C

Change into next month: -3.3°C

Can you swim or snorkel in Piran in October?

At 20.7°C our temperature-only guide describes the water as cool water. Comfort depends on your cold tolerance, immersion time and wind. A historical average cannot determine whether conditions are safe on any given day.

Do you need a wetsuit?

A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.

Which beach should you choose?

Look for a beach sheltered from the actual forecast waves and wind on your visit. Exposure, currents and entry conditions vary even where water temperatures are similar. Follow local warnings.

Check the current waves, wind and snorkeling forecast →

A live forecast does not predict a future October. Check again close to your trip.

Piran Sea Temperature: All 12 Months

Choose a month for available historical evidence, month comparisons and swim guidance. Missing history is clearly marked and never presented as a long-term normal.

January 12.3°C February 11.4°C March 11.8°C April 14.2°C May 18.1°C June 23.3°C July 26.1°C August 26.2°C September 24.1°C October 20.7°C November 17.4°C December 14.0°C

Data source and limitations

Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near 45.53, 13.57. Based on 3 yearly monthly means and 2232 recorded samples. Source methodology.

Modelled sea-surface temperatures do not establish underwater visibility, wildlife, calm currents or safe entry.