Methodology
How we score conditions
A closer look at how Kymataki turns weather and sea data into one of three categories — Great, Moderate, Rough — for every beach.
Last updated: 23 September 2026
The 3-tier system
Great
Calm sea, light wind, and clear weather — conditions score 8 or more out of 10 points.
Moderate
One or more factors (wind, waves, swell) are elevated, but swimming is still workable for most people — 4 to 7 points.
Rough
Fewer than 4 points, or an automatic downgrade whenever rain with a storm or hail is present, regardless of the other factors.
The 5 scoring factors
Each factor contributes points toward a total of 10 — the final category comes from the sum.
Wave height (up to 3 points)
Under 0.3m: 3 points · up to 0.8m: 2 points · up to 1.5m: 1 point · over 1.5m: 0 points.
Wind (up to 3 points)
Under 10 km/h (about Beaufort 2 or less): 3 points · up to 20 km/h (about Beaufort 3): 2 points · up to 30 km/h (about Beaufort 4): 1 point · over 30 km/h (about Beaufort 5+): 0 points.
Swell (up to 2 points)
Under 0.3m: 2 points · up to 0.7m: 1 point · over 0.7m: 0 points.
Sea temperature (up to 2 points)
22°C and above: 2 points · 18-22°C: 1 point · below 18°C or no reading available: 0 points.
Weather conditions (penalty)
Rain, snow, or fog subtract 2 points, and cloud cover subtracts 1 point. Rain with a storm or hail automatically downgrades to Rough, regardless of the other factors.
The total (up to 10 points) determines the category: 8+ = Great, 4-7 = Moderate, below 4 = Rough.
Data sources & update cadence
Wave, swell, and sea-temperature data come from the Open-Meteo Marine API, while wind, weather, and UV come from the Open-Meteo Forecast API. The data pipeline refreshes every beach every 3 hours.
Limitations
Kymataki is not an official meteorological, port, or lifeguard service. Readings come from forecast models, can diverge from real conditions, and refresh up to every 3 hours. Always check official announcements, flags, and the actual on-site conditions before swimming.