Pacifica (CA) Temperature by Month

Pacifica in California, United States of America sees moderate seasonal temperature shifts, with daytime highs between 14°C (57°F) in December and 22°C (72°F) in September, averaging 18°C (64°F) annually. Explore the full monthly breakdown below.

Seasonal changes in Pacifica bring a little variety without extreme temperature swings. Nighttime lows range from 12°C (54°F) in September to 7°C (45°F) in December.

The chart below illustrates the average maximum day and minimum night temperatures in Pacifica by month:

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. September, the warmest month, averages 270 hours of sunshine.

The chart below shows the average temperature throughout the year:

Pacifica's average annual maximum temperature is 18°C (64°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Zermatt, Switzerland averages just 4°C (39°F) annually due to its altitude, with very cold winters and cool summers even at its warmest.

Shanghai, China averages 21°C (70°F) a year, with warm summers, mild winters, and a noticeable spring and autumn.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In Pacifica, December is the coolest month, with average highs of 14°C (57°F) and humidity around 78%, considered high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Pacifica this rarely lasts long on the ground.

For more on Pacifica's weather, including monthly rainfall, sunshine hours, and humidity, visit our Pacifica climate page.