Piran Water Temperature
Updated Sat 14:41 (Europe/Ljubljana)
Slovenia · Forecast updated Sep 26, 2026, 14:41 UTC
Current Sea Temperature
23.8°C
74.8°F
Mild water
Valid Sep 26, 2026, 14:41 (Europe/Ljubljana). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
0.3°C below
The typical September average is 24.1°C (75.4°F) from the historical baseline.
Recent trend
Cooling by 0.8°C
Seven-day average: 24.8°C, versus 25.6°C in the prior seven days.
What to wear
Mild water
A rash guard is useful; cold-sensitive snorkelers may prefer a shorty wetsuit.
Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions or replace the snorkel forecast.
Typical Sea Temperature Over the Year
In the historical baseline for Piran, typical monthly averages range from about 11.4°C (52.5°F) in February to 26.2°C (79.2°F) in August.
Over the past 30 days, the average sea temperature in Piran has been 26.2°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Piran, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 11.2–13.1°C | 12.3°C / 54.1°F |
| February | 11.0–11.8°C | 11.4°C / 52.5°F |
| March | 11.3–12.8°C | 11.8°C / 53.2°F |
| April | 13.2–15.2°C | 14.2°C / 57.6°F |
| May | 17.1–18.7°C | 18.1°C / 64.6°F |
| June | 22.5–23.8°C | 23.3°C / 73.9°F |
| July | 25.8–26.5°C | 26.1°C / 79.0°F |
| August | 25.1–27.4°C | 26.2°C / 79.2°F |
| September | 24.0–24.2°C | 24.1°C / 75.4°F |
| October | 20.1–21.8°C | 20.7°C / 69.3°F |
| November | 16.7–18.1°C | 17.4°C / 63.3°F |
| December | 13.6–14.7°C | 14.0°C / 57.2°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (45.54, 13.54). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
Water temperature by month
Each month uses the 2023–2025 baseline. The range is the lowest and highest yearly monthly mean, not an hourly extreme.
Piran in January
Typical January water temperature near Piran is 12.3°C (54.1°F), with yearly monthly means from 11.2–13.1°C.
Piran in February
Typical February water temperature near Piran is 11.4°C (52.5°F), with yearly monthly means from 11.0–11.8°C.
Piran in March
Typical March water temperature near Piran is 11.8°C (53.2°F), with yearly monthly means from 11.3–12.8°C.
Piran in April
Typical April water temperature near Piran is 14.2°C (57.6°F), with yearly monthly means from 13.2–15.2°C.
Piran in May
Typical May water temperature near Piran is 18.1°C (64.6°F), with yearly monthly means from 17.1–18.7°C.
Piran in June
Typical June water temperature near Piran is 23.3°C (73.9°F), with yearly monthly means from 22.5–23.8°C.
Piran in July
Typical July water temperature near Piran is 26.1°C (79.0°F), with yearly monthly means from 25.8–26.5°C.
Piran in August
Typical August water temperature near Piran is 26.2°C (79.2°F), with yearly monthly means from 25.1–27.4°C.
Piran in September
Typical September water temperature near Piran is 24.1°C (75.4°F), with yearly monthly means from 24.0–24.2°C.
Piran in October
Typical October water temperature near Piran is 20.7°C (69.3°F), with yearly monthly means from 20.1–21.8°C.
Piran in November
Typical November water temperature near Piran is 17.4°C (63.3°F), with yearly monthly means from 16.7–18.1°C.
Piran in December
Typical December water temperature near Piran is 14.0°C (57.2°F), with yearly monthly means from 13.6–14.7°C.
Forecast archive (growing)
These values come from hourly forecasts SnorkelForecast has stored. They cover only months with records and do not replace the historical baseline.
| Month | Min | Average | Max |
|---|---|---|---|
| June | 21.5°C / 70.7°F | 24.6°C / 76.3°F | 28.5°C / 83.3°F |
| July | 24.7°C / 76.5°F | 26.8°C / 80.3°F | 28.9°C / 84.0°F |
| August | 26.5°C / 79.7°F | 27.8°C / 82.0°F | 29.6°C / 85.3°F |
| September | 23.4°C / 74.1°F | 25.7°C / 78.3°F | 27.9°C / 82.2°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2831 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Piran
Adriatic town with the Strunjan nature reserve's clear, sheltered shallows.
- Area
- Istria
Piran Water Temperature: Common Questions
What is the water temperature in Piran today?
The current sea surface temperature near Piran is 23.8°C (74.8°F). Over the last 30 days, the average has been 26.2°C.
When is the water warmest in Piran?
The water is typically warmest in August, at around 26.2°C (79.2°F) in the 2023–2025 historical baseline.
When is the water coldest in Piran?
The water is typically coldest in February, at around 11.4°C (52.5°F) in the same historical baseline. A wetsuit is usually recommended during this period.
Can you swim in Piran today?
At 23.8°C, the water is usually comfortable for swimming and snorkeling.
Full Snorkeling Forecast
See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Piran.
View Snorkel Forecast →