Sea Breeze vs Land Breeze — How Coastal Winds Work

The Daily Cycle

If you have spent time near the coast, you have probably noticed a pattern: wind blows from the sea during the day and from the land at night. This is not random — it is physics.

Sea Breeze (Daytime)

1. The sun heats the land faster than the ocean (land has lower heat capacity)
2. Hot air over the land rises, creating a low-pressure zone
3. Cooler, denser air from over the sea rushes in to fill the gap
4. This onshore wind is the sea breeze

Sea breezes typically start mid-morning and peak in the afternoon. They can extend 20-50 km inland and drop coastal temperatures by 5-10°C compared to areas further inland.

Land Breeze (Nighttime)

1. After sunset, land cools faster than the ocean
2. The ocean is now relatively warmer, with rising air above it
3. Cooler air from the land flows toward the sea
4. This offshore wind is the land breeze

Land breezes are generally weaker than sea breezes because the temperature contrast at night is smaller.

Why It Matters

• Sailors and surfers: Sea breezes create afternoon chop; mornings are glassier
• Coastal cities: Sea breezes keep coastal neighbourhoods cooler than inland suburbs
• Fog: Land breezes can push warm air over cool water, triggering offshore fog
• Thunderstorms: Sea breeze convergence zones (where two coastlines' breezes meet) can trigger afternoon thunderstorms in places like Florida

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Check coastal wind conditions on Weather Tomorrow.