A Mark Twain Moment: The Weather of Half Moon Bay

It was Mark Twain who reportedly quipped, "The coldest winter I ever spent was a summer in San Francisco." While he didn’t actually say it - aiming his barb instead at an unseasonably cold summer he spent in Paris, France, it is common knowledge that visitors to San Francisco in the summer often have to buy cheap fleece jackets in the souvenir shops because of the fog and decidedly unsummer-like chill in the air.


Half Moon Bay and the San Mateo Coastside mirror San Francisco in their weather patterns. Mild year-round with temperatures rarely exceeding 65 and rarely plummeting below 45, visitors need to dress in layers. And that’s hard to believe when you’re leaving 90 degree plus temperatures in August to come to our beautiful northern California coastline. But believe it! Check out the boring but accurate data provided by the U.S. government if you don’t believe me.

I’m a daughter of a Midwest meteorologist so I grew up chasing tornados and severe thunderstorms, digging out after snowstorms, and stopping the car to look at spectacular cumulonimbus cloud formations. It took me a few years to get used to the subtle differences in our weather here on the San Mateo Coast but now I love every season. And there are differences!

My absolute favorite time of year is winter. There’s a stealth summer that generally happens in February for a glorious few days of warm and lengthening days. It’s almost always fog-free in the winter months, so there’s ample opportunity to see breathtaking sunsets. And of course, there are the occasional winter storms. During the wet El Nino years, the Coast can be pelted over and over again. But generally the winter storms are rare, and when they occur, it’s exciting!

half moon bay sunrise

Winter also marks the time when the surf is up - with the Maverick’s Invitational "window" open from November to March when conditions are generally right for waves that can reach up to 40 feet. And it’s Dungeness crab season - these delectable crabs are sometimes called "Christmas crabs" and we always enjoy them around the winter holidays.

The warmest time in Half Moon Bay is from late August to early October. It’s sunny and warm and corresponds to the time the pumpkin patches suddenly spring up from nowhere (ok, many of them are trucked in for the hordes of tourists who come with their children to pick pumpkins in the fall.) But I adore the look of the orange pumpkins against a brilliant blue sky.

half moon bay pumpkin patch

I have observed that our foggiest months correspond to the school year - the day the kids get out of school (mid-June) the fog rolls in, and then it rolls back out when they return to school in late August. But the fog often burns off during the day, and our different microclimates mean that it can be socked in in Moss Beach and sunny in the El Granada banana belt. And just a couple miles inland there are hundreds of trails that are warmed by the sun. When my kids complained about the cold in the summer, I took them to the Central Valley where temperatures may be 50 degrees hotter. Believe me, after a day in Modesto, they were always ready to come home to cool Half Moon Bay.

I love all the weather of Half Moon Bay, but if you’d like guidance on planning your ideal visit time, we are happy to help here at Half Moon Bay Coastside Tours. Email me at This email address is being protected from spambots. You need JavaScript enabled to view it..

Check Out the Gallery

montarra beach