The sea in real time
Sea temperature, anomaly against the climate norm, marine heatwaves and stratification — updated several times a day from the data of the Copernicus Marine Service. Choose a coastal zone.
SST anomaly map — latest data
Deviation of the sea temperature from the 1999-2025 average: red = warmer than normal, blue = cooler. It is the most recent Copernicus daily mean (about a 24-hour latency); the exact date is shown at the top of the page. Interactive map.
Sea temperature — last 45 days
Observed SST compared with the seasonal norm and with the 90th-percentile threshold (the marine-heatwave limit).
The anomaly is the deviation from the mean temperature of that day of the year over the 1999-2025 period (Copernicus Med Sea Physics reanalysis). A marine heatwave is a period of at least 5 consecutive days above the 90th climatological percentile (Hobday et al. definition). The stratification is an anomaly index against the seasonal norm of the wind-mixed surface layer (MLD): 0 = MLD at the climatological median or deeper (normally or more mixed than usual); 100 = MLD in the 10th-lowest percentile of the historical record for that day of year (exceptional stratification, sea extremely still for the season). Wind and waves are 7-day forecast averages and maxima: a persistently calm sea strengthens the mucilage preconditions; strong wind and high waves dampen it.
The sea today: records and model validation
How close is the model? Comparison with real measurements
| Station | Source | Measured | Model | Deviation |
|---|---|---|---|---|
| Cetraro | ISPRA RMN | 25.5 °C | 26.7 °C | +1.2 |
| Crotone | ISPRA RMN | 26.7 °C | 27.4 °C | +0.7 |
| Reggio Calabria ⓘ | ISPRA RMN | 26.8 °C | 27.6 °C | +0.8 |
| Boa Crotone (6100210) | INSTAC (CMEMS in-situ) | 27.3 °C | 27.2 °C | -0.1 |
| Boa Cetraro (6100211) | INSTAC (CMEMS in-situ) | 27.1 °C | 26.6 °C | -0.5 |
Mean deviation at open-coast points: +0.3 °C. The model is a 4.2 km analysis: at coastal points the comparison uses the nearest sea cell. Reggio Calabria is a special case (Strait of Messina).
Real measurements: ISPRA National Tide Gauge Network and CMEMS In-Situ TAC (RON wave buoys), near-shore water temperature. They are used to quantify the model deviation.