Have you been wondering, “why is San Francisco so cold”? We’ll answer your question here!

Why is San Francisco so cold?

It’s a question you might have asked yourself if you’ve visited, or planning to visit.

If you’re trying to figure out what to pack for your vacation (or adore learning more about weather patterns in general!), keep reading.

Although San Francisco is in California, it doesn’t have quite the same beachy and balmy feel as the rest of the state. In fact, many people find themselves shivering and asking: “why is San Francisco so cold?”.

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This mini deep-dive should answer the question “why is San Francisco so cold?” and give you a bit of context for those chilly evenings during the summertime. 

Now without further ado, let’s figure out why San Francisco is so cold!

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Why Is San Francisco So Cold All The Time?

It’s no secret that San Francisco’s weather is approximately 10 degrees Fahrenheit colder than the rest of the country at any time.

And while you might think it’s solely down to that semi-aesthetic fog that you’ll find around the Golden Gate Bridge, there’s a lot more to this than meets the eye.

It’s right by the Bay Area which creates a low-pressure environment.

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So, the main answer to the question “why is San Francisco so cold” is down to the city’s location.

The Bay Area is tucked right between the ocean and the Central Valley. 

As you’ve also got the marine layer on the west of the city and heat in the east, you have the perfect combination of factors that creates a low-pressure environment with thin air.

In scientific terms, this means that the valley creates a layer of air over the entire city filled with cooler air near the marine layer. 

This pulls a “veil” over San Francisco which makes it quite a bit cooler than other parts of California.

The more you know, right!?

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Blame the fog!

But honestly, the creation of the city’s signature fog blocks quite a lot of those rays that would ordinarily make it to the land. 

So, this creates a blanket of cooler air that brings the temperatures down considerably. With less sunshine, you won’t get the same thermal gain on land that you’d get otherwise. 

And with less radiated energy, there’s simply less heat bopping around!

You’ll probably see warmer temperatures around Nob Hil and the Castro as they’re further inland where there’s less fog. 

But Richmond and areas surrounding the Bay are significantly cooler as they simply cannot escape the dreaded fog.

Just so you’re aware, it’s significantly foggier during San Francisco’s “fog season” (go figure!). 

This is thickest during the summertime, but you’ll also catch a thinner version during the winter called “tule fog” that doesn’t come down quite as low.

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It’s incredibly windy

And hey – part of why San Francisco is so cold can be attributed to the sometimes-crazy wind levels around these parts. 

Seriously, you’ll sometimes feel as though you’re going to be blown over as you stroll down the Golden Gate Bridge!

This is down to the fact that there is a lot of ocean upwelling here. As this happens, the wind brings colder layers of air right into San Francisco.

The fact that the chill wind is carried from the cold Alaskan current doesn’t exactly help either!

So, that certainly helps us answer the question “why is San Francisco so cold?”.

There you have it! The three reasons that cover “why is San Francisco so cold?”. 

Have you been to San Francisco? Were you surprised by how chilly this place was? We’d love to hear your thoughts in the comments below!

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