Northern California Climate

Home » Northern California » Northern California Climate

CLIMATE OF SAN FRANCISCO

Topography

San Francisco is in an area of “exceedingly diversified topography” (McAdie, 1903) that is favorable to numerous microclimates (McAdie, 1913; Gilliam, 1962). Winds are channeled over and around the City of San Francisco by the terrain, resulting in pronounced differences in the weather across relatively short distances (Root, 1960; Null, 1978).

The development of the extremely varied California landscape is a consequence of the interaction between of the North American and Pacific tectonic plates (Alt & Hyndman, 1975). The most prominent features, and most important in their effect upon state’s climate (Root, 1960), are the Sierra Nevada and Coast ranges, between which lies the Great Valley. All three, generally oriented from northwest to southeast, are parallel to the motion of the North American plate.

San Francisco, which is described by approximately a seven mile by seven mile square, sits at the northern end of a peninsula, straddling the Coast Range just south of where it is broken by the Golden Gate. The melting of the ice sheets that covered the North American continent during the Pleistocene caused sea level to rise and flood the structural depression which is now San Francisco Bay (Howard, 1962; Alt & Hyndman, 1991). Outflow from the Sacramento and San Joaquin Rivers, fed by the drainages from the surrounding Sierra Nevada and Coast Range, maintains the breach as the only major outlet to the Pacific. San Francisco’s steep topography is the boundary between the Pacific Ocean on the west, San Francisco Bay to the east and the Golden Gate to the north. The highest terrain is toward the south, where the elevations rise to over 900 feet, with Mount Davidson’s peak of 938 feet the tallest, followed closely by Mount Sutro at 920 feet and both North and South Twin at 919 feet. In addition to the primary north- northwest to south-southeast ridgeline, a number of significant hills dominate the San Francisco horizon, as spurs off of the main axis. The city’s steepness is shown by the fact that the 60 meter elevation contour is generally within one mile of sea level (United States Geological Survey, 1973a, 1973b).

Because of the small area that San Francisco covers there are no significant natural drainage basins within the city limits. Those which may have existed historically have long since been constrained to underground culverts and the storm drain system.

Climate

The sharp topography and maritime surroundings of San Francisco combine with the unique California climate to produce a number of extremely varied microclimates within its 46 square miles. California’s location in the middle latitudes and on the west coast of the North American continent, places it in the relatively rare Mediterranean (Etesian) type climate (K”ppen type Cs). The only other regions of the earth sharing this climate type are the southwestern tip of Africa, the west coast of Chile, the west coast of Australia, and of course, the region surrounding the Mediterranean Sea (Critchfield, 1966). This type of climate type is generally characterized by moist mild winters and dry summers.

San Francisco’s climate is further modified by the location of the City on the northern end of a peninsula, surrounded on three sides by the relatively cool waters of the Pacific Ocean and San Francisco Bay. In addition to the normal cool temperatures of the mid-latitude Pacific Ocean, the water temperatures are modified by the upwelling of cold water along the California coast. This phenomenon is caused by the persistence of the Pacific High and the northwest winds that are constrained by the Coast Range to blow parallel to the coastline. The effects of these winds, the Coriolis Force and resultant sub-surface Ekman Spiral, causes a net transport of surface waters away from the shore. Consequently, as the surface waters drift away from the coast, they are replaced by the upwelling of colder waters from below (Ahrens, 1991).

Summertime in San Francisco is characterized by cool marine air and persistent coastal stratus and fog, with average maximum temperatures between 60øF and 70øF, and minima between 50øF and 55øF. The mornings will typically find the entire city overcast followed by clearing on the warmer bay side, but only partial clearing on the cooler ocean side. The summertime temperature gradient across the city is generally from northwest to southeast, with the warmer readings farthest from the coast and in the wind sheltered valleys east of the Coast Range bisector. These differences are enhanced further by a strong afternoon and evening seabreeze that is a result of the temperature (and consequently pressure) difference between the Pacific Ocean and the interior valleys of California. These westerly winds are channeled through the Golden Gate and lesser breaks in the high terrain of the Coast Range, reaching a maximum during the afternoon with speeds between 20 and 30 miles per hour being typical (Root, 1960).

Rainfall from May through September is relatively rare, with an aggregate of less than an inch, or only about 5 percent of the yearly average total of approximately 21.5 inches. Off- season rains which do occur are usually the result of weak early or late season occluded fronts, or surges of subtropical moisture from the south that result in brief showers or thundershowers spreading into the area. Considerable moisture is due to drizzle when the marine layer deepens sufficiently. This is seldom enough to measure (i.e., less than .01 inch) on any given day, except along the immediate coast.

Winter temperatures in San Francisco are quite temperate, with highs between 55øF and 60øF and lows in the 45øF to 50øF range (Null, 1978). The main source region of wintertime fog in San Francisco is the Great Valley. Radiation fog is formed in the moist regions of the Sacramento River Delta and is advected through Suisun and San Pablo Bays and into San Francisco Bay on cool easterly drainage winds. This type of fog is less common than that of summer, but is typically much denser and has a greater impact upon transportation systems due to greatly reduced visibilities (Root, 1960).

Over 80 percent of San Francisco’s seasonal rain falls between November and March, occurring over about 10 days per month. Winter rains on the California coast are primarily due to occluded fronts on a trajectory from the west-northwest, and an occasional cold front from the Gulf of Alaska. These systems are driven southward during the winter as the Pacific High drifts south and westerlies and Polar jetstream dip south of 40øN. Winter thunderstorms occur on the average only twice per season in cold unstable post-frontal airmasses. There is also considerable areal variation of annual precipitation amounts. The isohyet (contours of equal rainfall) analysis developed by Rantz (1971) depicts a maximum (22 ” contour) over the higher terrain in the south central portion of San Francisco. This is primarily due to the orographic effects resulting from uplift of the airflow from the Pacific striking the Coast Range. The 20″ contour is along the western edge and also across the northeastern quadrant of San Francisco, with the 18″ contour just touching the waterfront in the extreme northeast.

Snow is extremely rare in San Francisco, with only 10 documented instances of measurable snow at the official observing site in the past 143 seasons. Snow has fallen on a number of other occasions, but usually only in trace amounts or at the higher elevations. Additionally, some of these occurrences are not true snow events but were the result of either small hail or ice pellets (Pericht, 1988).

Spring and fall are transition periods for San Francisco. These seasons usually produce the most cloud-free days between the overcast days of summertime stratus and the rain laden clouds of winter. San Francisco’s hottest days are typically during the spring and fall when high pressure builds into the Pacific Northwest and Great Basin, and dry offshore winds replace the Pacific seabreeze. The three hottest days in San Francisco occurred in September and October (Pericht, 1988).

The occurrence of rainfall during the early spring and fall is infrequent, with only about 5 days per month on the average. While most storms during these periods produce light precipitation, the occasional coupling of polar and subtropical airmasses can produce heavy rainfall events. For example, the “Columbus Day Storm” (October 11, 1962 through October 13, 1962) dropped over five inches of rain on San Francisco (Null, 1978). The diversity of San Francisco’s microclimates in general and its rainfall patterns in particular must be considered when utilizing the data from a single site. In a relatively flat region, without the influences of the ocean and topography, there is little discernible change in annual rainfall averages with distance. However, within a distance of only a few miles in San Francisco there can be as much as a 20 percent difference in average annual rainfall (i.e., from 18″ to 22″).
San Francisco Station Locations and History.

The DigiMarCon Difference

Business and marketing professionals have a lot of choice in events to attend.
As the Premier Digital Marketing, Media and Advertising Conference & Exhibition Series worldwide
see why DigiMarCon stands out above the rest in the marketing industry
and why delegates keep returning year after year

Global Event Series

DigiMarCon is the Largest Digital Marketing, Media and Advertising Conference & Exhibition series in the world, with annual events held in all continents (North America, Latin America, Europe, UK, Asia Pacific, Middle East and Africa) in 13 countries (United States, Canada, Australia, New Zealand, United Kingdom, Ireland, Netherlands, Spain, Brazil, Singapore, India, United Arab Emirates and South Africa), across 33 cities (New York, Philadelphia, Boston, Toronto, Vancouver, Montreal, Houston, Dallas, Chicago, Los Angeles, San Francisco, Seattle, Washington DC, New Orleans, Atlanta, Detroit, Miami, Denver, San Diego, Phoenix, Las Vegas, Honolulu, London, Dublin, Amsterdam, Barcelona, Johannesburg, Cape Town, Dubai, Sydney, Auckland, Singapore and Sao Paulo). All DigiMarCon Events can be attended in-person or online. Wherever you are located there is a regional DigiMarCon event nearby you can attend.

5-Star Luxury Event Venues

DigiMarCon Conferences are held in top luxury 5-star event venues across the world such as; Royal Caribbean Cruise Ships, Olympic Stadiums, Marina Bay Sands Expo & Convention Centre and Wynn, JW Marriott, Marriott Marquis, Hyatt Regency, InterContinental, The Westin, Renaissance, Hilton, Conrad, W, Sheraton, Loews and Sofitel Hotel properties. Discount hotel room rates at each venue hotel means no hassle getting to and from the venue each day.

Extensive & Memorable Networking Experiences

Building relationships matter! At DigiMarCon Conferences we have more networking breaks on our program than others. On average there are 8 Networking breaks at each event giving delegates ample opportunities in a relaxed atmosphere to meet others over the 2-days at the event; from 1-hour round table networking luncheons to 3-hour dinner receptions. These networking breaks are set in picturesque locations to facilitate memorable experiences while fostering new relationships. Such experiences include enjoying cocktails and the Sunset over the Pacific Ocean on a private Ocean Terrace in Santa Monica, to being on the Sydney Olympic Stadium playing arena at night enjoying cocktails under the lights, to dining at the 360 Revolving Restaurant at the top of the CN Tower in Toronto for a Dinner Reception, enjoying cocktails on a private promenade overlooking Times Square in New York City, or having fun at the Dazzles Night Club onboard the Royal Caribbean Oasis of the Seas for a Farewell Party, etc.

Industry Thought Leaders from Leading Brands

DigiMarCon Keynotes, Panels and Master Classes are facilitated by the foremost thought leaders in the industry, from celebrity social media influencers to CMO’s from the largest Fortune 500 company brands that are disrupting the digital marketing, media and advertising industry, such as Google, Facebook, Microsoft, Amazon, Oracle, Adobe, eBay, Netflix and more. All presentations are pitch-free, and include actionable takeaways, case studies, strategies and tactics, ready to be applied when back in the office.

Premium Comfortable Meeting Spaces

At DigiMarCon Conferences you are never ‘left in the dark’…. literally, in a large room far away from the stage and speakers, crushed in tight theater seating, without even a table, while sitting in the dark. At DigiMarCon all delegates have premium meeting space in luxurious ballroom well-lit spaces, with comfortable seating with table enabling delegates to use their laptop to take notes with ample charging facilities onsite in a comfortable space to learn and thrive. All tables are situated close with direct view of the stage.

Value for Money & Generous Discounts

DigiMarCon Conferences are affordable to attend, from single-day event passes up to two-day VIP options at a fraction of the cost of other industry events. We offer significant discounts for early bird registrations. Additionally, on top of time-limited discount pass rates, because budgets are tight, we want to make sure all groups have a chance to attend DigiMarCon. For government employees, students, academic, startups, non-profit organizations and teams, we offer generous discounts off the prevailing registration price.

Collaborative Learning & Audience Participation

Attend DigiMarCon and you become part of the show! DigiMarCon Conferences tap into the talent of the room, drawing from the knowledge and experience of the professionals in the audience. All DigiMarCon events include regular interactive question and answer sessions with speakers and the audience ideal for collaboration, audience polls, along with ice-breaker and group exercises, steered by charismatic Emcees.

Meet the Speakers in Person

DigiMarCon Conferences put you right up and close with the speakers giving you the opportunity to meet these social media influencers which you follow in person. Speakers are never hidden in private speaker rooms away from the audience, they are in the auditorium sitting right beside you and participating.

Exceptional Customer Service

Attending a conference is a well-researched decision. There are many factors to consider such as location, time, venue, cost, speakers, content, etc. At DigiMarCon our results-obsessed Customer Service team are at your service before, during and after the event to help with your needs. It’s at the core of what we do — it drives our business. Offsite, we are ready to assist you via phone, ticket or chat. Onsite at our Conferences, friendly DigiMarCon staff serve as your hosts. They welcome your input and are happy to assist you.

TECHSPO Technology Expo

At all DigiMarCon Conferences is the co-located exclusive event TECHSPO Technology Expo, which showcases the new generation of technology and innovation, including; AdTech, MarTech, Internet, Mobile and SaaS technologies. Be inspired, amazed and educated on how these evolving technologies will impact your business for the better. Unlimited Access to TECHSPO Technology Expo is included with all DigiMarCon passes.

On Demand Library Access

DigiMarCon All Access & VIP Passes include a 12-month on demand access to hundreds of hours of DigiMarCon speaker keynotes, panels and master class presentations from recent DigiMarCon Conferences, including videos, slide decks and key takeaways, available on demand so you can watch what you want, when you want.

The Largest Digital Marketing, Media & Advertising Community

Attendees of DigiMarcon Conferences gain membership to an exclusive global Digital Marketing, Media and Advertising Community of over 500,000 worldwide subscribers to our award-winning digital marketing blog and over 100,000 members to the International Association of Digital Marketing Professionals (visit https://iadmp.org). This global community comprises of innovators, senior marketers and branders, entrepreneurs, digital executives and professionals, web & mobile strategists, designers and web project managers, business leaders, business developers, agency executives and their teams and anyone else who operates in the digital community who leverage digital, mobile, and social media marketing. We provide updates to the latest whitepapers and industry reports to keep you updated on trends, innovation and best practice digital marketing.

Safe, Clean & Hygienic Event Environment

The events industry has forever changed in a world affected by COVID-19. The health and safety of our guests, staff and community is our highest priority and paramount. The team at DigiMarCon is dedicated to ensuring a great experience at our in-person events, and that includes providing a safe, clean and hygienic environment for our delegates. Some of the key areas we have implemented safe and hygienic measures include;

  • Limiting Venue Capacities to allow for Social Distancing
  • Health and Safety Protocols
  • Safe Food and Beverages and Food-handling
  • Sanitation Stations with Hand Sanitizer and Wet Wipes Dispensers
  • Sanitation and Disinfection of Common and High-Traffic Areas
  • Physical Distancing Measures Between Attendees
  • Social Distancing Room and Seating Configurations
  • Non-Contact Thermal Temperature Scanning

Hybrid Events: Attend In-Person or Online

DigiMarCon has always been industry leaders of the Hybrid Event experience for years (a hybrid event combines a "live" in-person event with a "virtual" online component), no one needs to miss out on attending our events. Each DigiMarCon Conference can be attended in-person (with a Main Conference, All Access or VIP Pass) or online (with a Virtual Pass) giving attendees a choice for the experience they want to have. Attending virtually by viewing a Live Stream or On Demand enables participation by people who might be unable to attend physically due to travel or time zone constraints or through a wish to reduce the carbon footprint of the event. If you would like to meet the speakers, network with fellow marketing professionals at refreshment breaks, luncheons and evening receptions, check out the latest Internet, Mobile, AdTech, MarTech and SaaS technologies providers exhibiting then it is highly recommended to attend DigiMarCon in-person. As the largest Digital Marketing, Media and Advertising Conference series with events in 33 international cities worldwide, across 13 countries, there is bound to be a DigiMarCon Event near you to attend in-person if you can.

High-Profile Audience From Leading Brands

DigiMarCon Conference Series is the annual gathering of the most powerful brands and senior agency executives in your region. The Sharpest Minds And The Most Influential Decision Makers - Together for Two Days.

Who Attends Our Conferences
Brands • Agencies • Solution & Service Providers • Media Owners • Publishers • Entrepreneurs • Start-Ups • Investors • Government • Corporates • Institutes of Higher Learning