Trying to make sense of South San Francisco’s housing market can feel like alphabet soup. You hear “inventory,” “DOM,” and “months of supply,” but what do they actually tell you about timing, pricing, and competition? You deserve a clear, plain‑English guide you can use to plan your next move. In this overview, you will learn what each metric means, how to read them together, and how local factors in South San Francisco influence demand and supply. Let’s dive in.
South San Francisco at a glance
South San Francisco sits on the northern end of San Mateo County with quick access to San Francisco and SFO. Caltrain, regional buses, and major roadways make it a commuter hub for Bay Area workers. The city is largely built out, so zoning choices, transit‑oriented projects, and new multifamily construction drive incremental supply. A strong cluster of biotech and life‑sciences employers also shapes demand and price sensitivity.
Seasonality matters. Springs tend to be more active and winters quieter, while mortgage rates, stock market moves, and regional hiring swing buyer confidence. Because SSF is a smaller city, month‑to‑month numbers can jump around. For a clear picture, use rolling 3‑ or 12‑month averages and compare by property type.
Four key market metrics
Inventory (active listings)
Inventory is the count of properties actively for sale at a point in time. It answers a simple question: how many choices do buyers have today. When inventory rises, buyers often gain negotiating room. When inventory falls, sellers usually have the advantage.
How to measure it: pull the number of active residential listings with City = South San Francisco from the MLS and filter by property type if you want apples‑to‑apples comparisons. Watch out for listings in very different price ranges or new‑construction units that can skew the count.
Median sale price
The median sale price is the middle price of homes sold in a period. Half of the sales closed above it and half below. It shows what buyers are actually paying and is less affected by extreme outliers than the average.
How to measure it: use closed sales over a defined period, like the last 30, 90, or 365 days, and state the period in your snapshot. Be careful about “mix shift.” If more condos than single‑family homes sell in a month, the median can move even if like‑for‑like values are steady. Include price per square foot or split by property type for clarity.
Days on market (DOM)
DOM tracks how long it takes a listing to get an accepted offer or close, depending on the data source. Lower DOM signals faster sales and stronger seller leverage. Higher DOM suggests buyers have more time and may face less competition.
How to measure it: use the median DOM for closed or pending sales in your chosen period. Note whether your source reports DOM until pending or until closing. Some listings can be withdrawn and relisted, which may reset DOM. If available, use cumulative days to get a truer read.
Months of supply (MoS)
Months of supply shows how long it would take to sell the current inventory at the current sales pace. It is calculated as active listings divided by the average number of closed sales per month in the same period.
Use these common thresholds:
- Less than about 3 months: seller’s market
- About 3 to 6 months: balanced market
- More than about 6 months: buyer’s market
Best practice is to use a 3‑ or 12‑month average for monthly sales to smooth seasonality. Split single‑family homes and condos because their MoS often differs.
Related metrics to watch
- Sale‑to‑list price ratio: sale price divided by the last list price. This shows whether homes sell at, above, or below asking.
- New listings vs pending ratio: compares fresh supply to homes going into contract in the same period.
- Price per square foot: useful for neighborhood‑level comparisons inside SSF.
- Inventory by price band: entry‑level and higher‑end segments can move very differently.
- Pending‑to‑active ratio: pending sales divided by active listings, a quick read on market liquidity.
How to read the SSF market
Hot seller’s market
Signs: low inventory, months of supply under about 3, falling DOM, and a sale‑to‑list ratio at or above 100 percent. You can expect competitive bidding and quick timelines. Buyers may need clean offers and fast decision making. Sellers who price correctly can see multiple offers.
Balanced market
Signs: moderate inventory, months of supply around 3 to 6, and DOM in the 2 to 6 week range. Prices tend to be flat or slowly rising, and sale‑to‑list often runs near 98 to 101 percent. Buyers and sellers both negotiate. Concessions are possible when a home sits or needs updates.
Cooling or buyer’s market
Signs: rising inventory, months of supply above about 6, longer DOM, and softening median prices. Buyers have time to compare options and may see price reductions. Sellers often adjust list prices or offer incentives to meet the market.
Mixed signals happen
Different segments in SSF can move in different directions at the same time. Condos may cool while single‑family homes stay brisk. If inventory rises but the median price also rises, it could be a sales‑mix shift toward higher‑priced homes. If DOM ticks up but sale‑to‑list stays high, it can mean buyers are selective yet still pay premiums for the best listings. Always cross‑check metrics and use multi‑month averages.
Set up smart saved searches
Use targeted searches to monitor the parts of the SSF market that matter to you. Set alerts to “immediate” if you are actively buying, or weekly if you are early in your research.
- First‑time or entry buyer
- City: South San Francisco
- Property type: condos or townhomes, or 2+ bed single‑family within an entry‑level budget
- Beds: 2+, Baths: 1.5+
- Alerts: immediate or daily
- Move‑up buyer
- Property type: single‑family detached
- Beds: 3+ in your mid‑market price band
- Filters: lot size and garage if important
- Alerts: daily or weekly
- Investor or rental buyer
- Property type: multi‑family
- Price range: wide, based on return goals
- Note: portals do not show cap rates. Ask for off‑MLS comps and rent data
- Alerts: immediate
- Seller monitoring comps
- Address radius: 0.5 to 1 mile
- Property type: same as your home
- Filters: similar beds, baths, and lot size
- Sort: newest or price per square foot
- Alerts: weekly
How to use listing alerts
- Choose your city and property type filters, then save your search and set alert frequency.
- When an alert arrives, compare the new listing to closed sales from the last 90 days with similar features.
- Check its days on market and any price changes since list. That context helps you gauge urgency and pricing.
- If a home fits, tour quickly. If it sits, watch for reductions and review sale‑to‑list ratios in that price band.
Data sources and best practices
For the most accurate picture, use the local MLS for active, pending, closed, DOM, and sale‑to‑list data. The San Mateo County Assessor and Recorder can complement MLS records for sales verification. State and regional reports from REALTOR associations add useful context. Public research dashboards can help with historical trends, but methods differ by source.
Best practices:
- Always state your reporting period, such as last 90 days or trailing 12 months, and keep periods consistent across metrics.
- Use medians for prices and DOM to reduce outlier effects.
- Split single‑family homes and condos or townhomes for clearer comparisons.
- Calculate months of supply as active listings divided by average monthly closed sales from the same period.
- Note how DOM is defined in your data and whether relisted properties reset the clock.
- Cross‑check MLS figures with one public source to understand any methodology differences.
What to watch next in SSF
- Seasonality: expect spring activity to pick up and winter to ease, even in steady years.
- Mortgage rates: rate changes directly influence monthly payments and buyer demand.
- Local jobs: shifts in biotech and tech hiring affect demand and price elasticity.
- Supply: with limited greenfield sites, new supply comes mostly from zoning changes and transit‑oriented multifamily projects. Watch for new buildings near transit that add inventory to the condo or townhome segment.
Your next step
Whether you are planning to buy, sell, or evaluate an investment or specialty property, you will move faster and with more confidence when these metrics are at your fingertips. If you want a current, property‑type‑specific snapshot for South San Francisco, ask for a personalized MLS report with rolling averages and months‑of‑supply calculations. For homeowners, a pricing consult tied to local comps and DOM trends can remove guesswork and reduce time on market.
If you are ready to make a move or want a free home valuation tailored to your address, connect with Vilma Palaad. You will get local, data‑driven guidance and a plan that fits your goals.
FAQs
What does “months of supply” mean in South San Francisco?
- It is how long the current inventory would take to sell at the recent sales pace. Under about 3 months often favors sellers, 3 to 6 months is balanced, and above about 6 months favors buyers.
How should I read median price for my SSF home?
- Treat the citywide median as a starting point. For pricing your home, compare similar properties within 0.5 to 1 mile with the same beds, baths, lot size, and look at price per square foot.
Why do SSF numbers swing month to month?
- SSF is a smaller market, so fewer sales can make percentages jump. Use rolling 3‑ or 12‑month series and separate single‑family from condos to smooth noise.
What is a healthy days on market in SSF?
- It depends on the segment. Lower DOM means faster sales and more seller leverage, while higher DOM signals buyers have more time. Compare DOM within your price band and property type.
How can I track the SSF market without getting overwhelmed?
- Set up saved searches with alerts for your segment, check new listings against recent closeds, watch inventory and months of supply monthly, and ask for a quarterly MLS snapshot to stay current.
