San Diego Weather: Fog, Cooler Temperatures, And Possible Light Showers

4 min read Post on May 30, 2025

San Diego Weather: Fog, Cooler Temperatures, And Possible Light Showers

Unusually Dense Fog in San Diego

San Diegans are waking up to a different kind of sunrise these days – one shrouded in unusually dense fog. This unexpected atmospheric phenomenon is impacting visibility and daily routines across the city.

Causes of Increased Fog:

Marine layer inversion: A marine layer inversion occurs when a layer of warm air sits above a layer of cooler, moist air near the surface. This traps the moisture, preventing it from rising and dissipating, leading to the formation of fog. The warmer air acts like a lid, keeping the cooler, foggier air close to the ground.
High pressure systems: High-pressure systems often push warmer air aloft, further contributing to the inversion and trapping the marine layer fog. This creates a stable atmospheric condition that inhibits vertical mixing and keeps the fog dense.
Cooler ocean temperatures: Cooler-than-average ocean surface temperatures provide more moisture for fog formation. This cooler water evaporates, creating more water vapor in the lower atmosphere, which then condenses into fog.

Impact of Fog on Visibility and Travel:

Reduced visibility: The dense fog significantly reduces visibility, leading to potential traffic delays and hazardous driving conditions. Motorists should exercise extra caution.
Increased risk of accidents: Reduced visibility increases the risk of traffic accidents. Drive slowly, increase following distances, and use your headlights.
Disruption to air and sea travel: Fog can cause delays and cancellations for flights departing from or arriving at San Diego International Airport (SAN) and can also impact sea travel and port operations. Check with your airline or ferry service for updates.
Safe driving in foggy conditions: When driving in foggy conditions in San Diego, remember to turn on your headlights (low beams), reduce your speed significantly, increase your following distance, and avoid sudden braking or lane changes.

Cooler than Average Temperatures

Along with the fog, San Diego is experiencing cooler-than-average temperatures for this time of year. This unexpected dip in temperature is impacting daily life and outdoor activities.

Temperature Drop Explained:

Influence of the marine layer: The persistent marine layer is preventing daytime heating by blocking the sun's rays from reaching the ground. This keeps temperatures lower than usual.
Impact of wind patterns: Changes in wind patterns are contributing to the cooler temperatures by bringing in cooler air masses from the ocean. These winds are circulating the cooler air closer to the coastline.
Comparison to historical averages: While specific data varies depending on the location within San Diego County, many areas are experiencing temperatures 5-10 degrees Fahrenheit below the historical average for this time of year.

What to Expect:

Predicted temperatures: The forecast predicts daytime highs in the low 60s Fahrenheit (mid-teens Celsius) and nighttime lows in the mid-50s Fahrenheit (low teens Celsius) for the next few days.
Appropriate clothing: Pack layers of clothing, including jackets, sweaters, and long pants to stay warm.
Adjusting activities: Consider postponing outdoor activities that are sensitive to colder temperatures, such as surfing or beach volleyball, until the weather improves.

Possibility of Light Showers

In addition to fog and cooler temperatures, there's a chance of light showers in some parts of San Diego County.

Chance of Precipitation:

Percentage chance of rain: The current forecast predicts a 30-40% chance of light showers over the next few days.
Areas most likely to experience rainfall: Coastal areas and mountain regions are most likely to see any precipitation.
Type of precipitation: The precipitation is expected to be light, in the form of drizzle or light showers.

Preparing for Light Showers:

Checking weather forecasts: Check your local San Diego weather forecast regularly for updates on precipitation and temperature changes. Multiple weather sources offer this information, from local news channels to dedicated weather apps.
Having appropriate gear: Have an umbrella or raincoat readily available.
Unexpected heavier rain: If heavier rain unexpectedly occurs, seek shelter immediately and avoid driving in flooded areas.

Conclusion

San Diego's weather is currently experiencing a deviation from its typical sunny and warm conditions, featuring unusual fog, cooler-than-average temperatures, and a chance of light showers. Understanding these changes allows for better preparation and safer navigation of daily activities. Staying informed about the San Diego weather forecast is crucial. Check your local news and weather apps frequently for updates on San Diego weather conditions and plan your day accordingly to avoid any inconvenience due to the fog, cooler temperatures, or light showers. Remember to stay safe and enjoy San Diego despite the temporary shift in weather patterns.