Diurnal Amplitude Mapping – Latitude-Based Charts for Daily Wind Build & Drop
Not all thermal winds are created equal. A rider in Norway experiences a completely different wind cycle than a rider in Brazil. The driving factor is Latitude.
We map the "Diurnal Amplitude"—the difference between the midday wind peak and the midnight calm. Understanding this helps you plan your session and avoid being stranded when the wingfoil wind shuts off.
The Tropics (0° – 23° Latitude)
Locations: Brazil, Caribbean, Hawaii. The Cycle: Binary. The sun rises and sets at the same time all year (approx 6 AM / 6 PM). The heating is intense and consistent.
- Amplitude: Moderate.
- Behavior: The trade winds often blow 24/7. The thermal wind effect just adds a 5-knot boost in the afternoon. You rarely get a "glass off" at sunset; you just get slightly lighter wind.
- Strategy: You can wingfoil until midnight if you want. The wind is reliable.
The Mid-Latitudes (30° – 50° Latitude)
Locations: USA, Europe, Mediterranean. The Cycle: Extreme Amplitude. Day length varies wildly. In summer, the days are long (16 hours). The land heats up massively, while the ocean stays cool.
- Amplitude: Massive.
- Behavior: The day can start dead calm (0 knots). By 4 PM, the thermal wind spikes to 25 knots. By 8 PM, it crashes to zero.
- Strategy: You are on a clock. You must be off the water before the "sunset crash." The wind speed can drop from 20 knots to 5 knots in 15 minutes.
The High Latitudes (50°+ Latitude)
Locations: UK, Scandinavia, Canada. The Cycle: Weak but Long. The sun angle is low. The heating is less intense. However, in summer, the sun never really sets.
- Amplitude: Low.
- Behavior: Sea breezes are weaker (10–15 knots) but they last forever. You can ride at 10 PM in broad daylight.
- Strategy: Use big wings and high-aspect foils. The wind gusts are gentle.
The Amplitude Chart
| Latitude | Region | Typical Build | Peak Time | Sunset Drop |
|---|---|---|---|---|
| 0°-20° | Tropics | +5 kts | 2:00 PM | Gradual (-5 kts) |
| 30°-45° | Mid-Lats | +15 kts | 4:00 PM | Sudden (To Zero) |
| 50°+ | North | +10 kts | 5:00 PM | Very Slow |
Summary
Check your latitude.
- Tropics: Relax. The wind will stay.
- Mid-Latitudes: Hurry. The thermal wind is a spike, not a plateau.
- North: Chill. Enjoy the long, light evening session.