The Bay Area Is a Tree Failure Zone
The Bay Area’s climate creates a specific, predictable pattern of tree failure that most homeowners don’t see coming. We get 6–8 months of drought followed by intense atmospheric rivers that dump inches of rain in hours. Trees that looked perfectly healthy in October snap, uproot, or shed massive limbs by January.
After 13 years in arboriculture — including emergency tree response across the Bay Area — I can tell you the failures are almost never random. The same species fail in the same ways, on the same types of sites, for the same reasons. This guide is what I wish every homeowner knew before storm season.
Key Takeaways
- Monterey pines, blue gum eucalyptus, and Monterey cypress are the top three species for storm failures on the Peninsula
- Inspect trees in October before the wet season — look for deadwood, co-dominant stems, root heaving, and fungal fruiting bodies
- Never go outside during a storm to deal with a falling tree — wait until winds drop below 30 mph
- Most homeowner policies cover damage from fallen trees but not the cost of removing a standing hazard tree
- Even storm-damaged heritage trees may require a permit to remove — emergency exemptions vary by city. Check permit guides for Los Altos and other cities
- A 30-minute walk around your property with a checklist in early fall can prevent thousands in storm damage
This guide is for before the storm. If a tree has already fallen, is leaning dangerously, or a branch is hanging over your house, use our Emergency Tree Guide for step-by-step instructions on what to do right now.
The 5 Species Most Likely to Fail
Not all trees are created equal in storms. These five species account for the majority of emergency calls I respond to every winter across the Bay Area.
Coast live oaks are the most wind-resistant species in the Bay Area. Their deep root systems, dense wood, and aerodynamic canopy shape make them remarkably storm-proof when healthy. If your yard has oaks, they’re your anchors — protect them. The main risk to oaks is root damage from construction or soil compaction, not wind.
The Pre-Storm Inspection: What to Look For
You don’t need to be an arborist to spot the warning signs. Walk your property and look at every tree from 30 feet away, then up close at the base. Here’s what should concern you.
At the Base
Soil heaving or cracking around the root flare — the area where the trunk meets the ground — means the roots are losing their grip. This is the single best predictor of uprooting. If you see a mound of raised soil on one side of the tree, the roots on the opposite side may have already failed.
Mushrooms or conks (shelf-like fungal growths) at the base indicate root decay. The fruiting body you see is a small fraction of the fungus inside. By the time mushrooms appear, significant structural wood may already be compromised.
Severed roots from construction, sidewalk repair, or utility work within the last 1–3 years. Root damage is cumulative and delayed — a tree can look fine for 2 years after root cutting, then fail in the next storm.
In the Canopy
Dead branches — no leaves when the rest of the tree is leafed out (for deciduous species, check for brittle bark and snapping twigs). Dead branches fall first and fall farthest because they’re lighter and catch wind differently.
Codominant stems — two trunks of equal size emerging from the same point, often with a visible seam or bark inclusion between them. This is the #1 structural defect in urban trees. The joint has no structural wood connecting the two stems; wind load will eventually split them apart.
Heavy lean toward a structure that wasn’t there before, or a lean that’s gotten worse. Healthy trees can grow at an angle permanently, but a new lean means something has changed underground.
If you checked even one box , it’s worth a professional assessment. An arborist can tell you in 30 minutes whether a tree is a genuine risk or a cosmetic concern. At $300–$600 for a site visit and report, it’s cheap compared to the deductible on a roof claim.
When to Call a Professional vs. Wait
Not everything needs an arborist. Here’s how I’d prioritize if I were a homeowner looking at my own trees.
Eucalyptus within one tree-length of your house. These trees fail without warning. If a 60-foot eucalyptus can reach your roof, get it assessed now.
Soil heaving or new lean. These symptoms mean root failure is already underway. The tree may fall in the next storm.
Codominant stems on any tree over 30 feet tall. This is a structural time bomb. One season of heavy rain followed by wind is enough to split it.
Dead branches over 4” in diameter. They’ll come down eventually. Better to remove them controlled than wait for them to land on something.
Branches touching your roof. During wind, these act like battering rams. Clearance pruning is straightforward and typically $300–$800.
Monterey pines with visible pitch canker. Oozing sap, dead branches, and yellowing needles. Get a professional assessment to determine if the structural wood is compromised.
Small dead branches (under 4”). Normal shedding. Not a structural concern.
Surface roots visible but no soil heaving. Common in clay soils. Not a stability issue by itself.
Trees that have always leaned. A consistent lean that hasn’t changed is usually fine — the tree has adapted. Only a new or worsening lean is concerning.
During the Storm: What to Do and Not Do
When the atmospheric river is hitting, your only job is to stay inside and stay safe. Here’s what I tell every client before storm season.
Do not go outside to check on trees during the storm. The most dangerous moment is when wind and saturated soil combine — trees that stood for 50 years can fail without any cracking sound. Limbs fall faster than you can react.
Stay away from windows facing large trees. If a limb comes through a window, you don’t want to be sitting next to it.
If you hear cracking or a tree falls, move to the interior of the house, away from the impact side. Do not go outside to assess. Wait until the wind subsides.
If power lines are involved, do not approach. Stay at least 35 feet away. Call 911 if lines are arcing or sparking, and PG&E at 1-800-743-5000 to report the line.
After the Storm: The First 24 Hours
Once the wind stops and it’s safe to go outside, here’s your priority order.
First: look up. Before you walk under any tree, look for hanging branches. These are called “widow-makers” for a reason. A branch wedged in the canopy can fall hours or days after the storm.
Second: check the root zones. Walk around the base of every large tree. Look for fresh soil cracks, lifted soil, or exposed roots. A tree that partially uprooted but is still standing can finish falling in the next breeze.
Third: document everything. Before you touch anything or call anyone, take photos. Wide angles showing the tree’s position relative to your house. Close-ups of damage. The tree’s root plate. Your insurance adjuster needs these.
Our Emergency Tree Guide walks you through exactly what to do, who to call, and what to document based on your specific situation — whether a tree hit your house, a neighbor’s tree fell on your property, branches are hanging over the road, or you’re not sure whose tree it is.
What Your Insurance Actually Covers
This is where most homeowners get surprised. Here’s the reality.
If a tree hits your house: Your homeowners insurance covers the structural damage and typically $500–$1,000 toward removing the tree from the structure. This is standard on most policies.
If a tree falls in your yard and hits nothing: Your insurance almost certainly does not cover removal. You’re paying out of pocket. For a large tree, that’s $1,500–$5,000+. Use our Cost Estimator for a more specific number.
If a neighbor’s tree hits your property: Counter-intuitively, your insurance covers the damage, not theirs. Your insurer may pursue the neighbor if the tree was visibly dead or hazardous and they were previously notified (this is called subrogation).
If a city street tree falls: File a tort claim with the city. Your homeowners insurance also covers the damage. Keep records of which tree it was and its location between the sidewalk and curb.
A pre-storm arborist assessment costs $300–$600. If the arborist identifies a hazard tree and you remove it, you’ve prevented a claim, saved your deductible ($1,000–$2,500), and avoided the rate increase that follows tree damage claims. If the arborist says your trees are sound, you sleep through the storm. Either way, you win.
Do I Need a Permit to Remove a Storm-Damaged Tree?
This is a question I get on every emergency call. The short answer: most Bay Area cities waive permit requirements for trees posing immediate danger. But there are important details.
If the tree is an active hazard (leaning toward your house, roots have failed, branches hanging over a walkway), you can perform emergency work without a prior permit. But you must notify your city within 24–72 hours (varies by city) and may need a retroactive permit.
The critical thing: document the emergency before any work begins. Photos of the hazard, the failure, and the conditions are what justify the emergency removal after the fact. Without documentation, the city may treat it as an unpermitted removal and issue penalties.
Penalties for unauthorized removal range from $500 in Redwood City to 3× the tree’s appraised value in Saratoga and Sunnyvale — potentially $100,000+ for a large heritage tree . Don’t assume storm damage gives you a free pass.
The 30-Minute Investment
Here’s what I’d do if I were a Bay Area homeowner heading into storm season.
Spend 15 minutes walking your property with the checklist above. Look at every tree from 30 feet, then at the base. Note anything that concerns you. Take photos.
Spend 5 minutes with our tools. Run any concerning trees through the Permit Checker to know if they’re protected. Check the Cost Estimator so you’re not blindsided by pricing.
Spend 10 minutes on the phone with a certified arborist if anything on your walk concerned you. Describe what you saw. Most arborists will tell you over the phone whether it warrants a site visit or if you can monitor it yourself.
That’s 30 minutes before storm season versus days of insurance claims, contractor negotiations, and structural repairs after.
Free: Bay Area Tree Owner’s Checklist (PDF)
This inspection checklist, city-by-city permit rules, 5 questions to ask before hiring, and emergency steps.
When a tree does come down on your property, the next steps matter. See our guide: What to Do If a Tree Falls on Your Fence in San Jose — covers safety, insurance, city rules, and who pays.