Coastal Sea Breezes and Daily Pressure Swings
A sea breeze produces a real but small pressure change — typically one to two millibars as the front passes, against the ten to thirty millibars a storm system delivers. What makes it worth knowing about is that it happens on a schedule, most afternoons in the warm season, and it arrives packaged with abrupt shifts in temperature, humidity and wind. If your worst days cluster in coastal summer afternoons, the pressure is probably the smallest part of what is hitting you.
If you live within twenty miles of a coast and your symptom log looks frustratingly noisy from May to September, this is one of the reasons.