Some San Diego neighborhoods see power shutoffs that coastal homes never do. Here is how to find out whether your address is in the High Fire Threat District, what that means for outages, and how to size backup power for a larger inland home.
Key takeaways
- The CPUC’s statewide fire threat map rates areas Tier 2 (higher risk) or Tier 3 (extreme risk). Together with Tier 1 High Hazard Zones, they make up the High Fire Threat District.
- You can look up your address on the CPUC’s interactive Fire Threat Map. Tier lines don’t follow city limits or ZIP codes.
- Homes in or near the HFTD are more likely to see SDG&E power shutoffs, and some qualify for SDG&E’s Generator Assistance Program.
- Larger inland homes can choose partial backup for essentials or whole-home backup, and a Powerwall 3 system can grow to as many as seven units.
- Solar recharging is what turns hours of battery backup into days.
Frequently asked questions
What is an SDG&E High Fire Threat District?
The High Fire Threat District (HFTD) is made up of Tier 2 (higher risk) and Tier 3 (extreme risk) areas on the CPUC’s statewide fire threat map, along with Tier 1 High Hazard Zones from the state’s tree mortality map. Utilities apply stricter safety rules there, and they’re the areas where SDG&E is most likely to shut off power during Santa Ana winds.
How do I find out if my home is in Tier 2 or Tier 3?
Open the CPUC’s interactive Fire Threat Map, click the magnifying glass icon, type your address and look at the shading around your home. Check your own address rather than your neighbor’s, because two homes in the same neighborhood can land in different zones.
Are Poway, Rancho Bernardo and Scripps Ranch in the High Fire Threat District?
Parts of these communities sit near or inside fire-threat areas, which is why they see shutoff watches that coastal neighborhoods rarely do. In early October 2026, SDG&E named Poway and Ramona among the areas that could see shutoffs. Tier boundaries vary, so look up your exact address.
Does living in the HFTD qualify me for help with backup power?
It can. SDG&E’s 2026 Generator Assistance Program offers rebates toward a fuel generator or portable power station to customers in Tier 2 or Tier 3 areas who have experienced at least one PSPS.
Can a home battery back up a well pump or central air?
Yes, if the system is designed for it. The Powerwall 3 is rated for motor starting current (185 A locked rotor, per Tesla’s datasheet), but large loads like central air and pool pumps drain the battery faster, so your installer should check each motor load against the design.
Ask someone in Carlsbad about a Public Safety Power Shutoff and you may get a blank look. Ask someone east of the I-15 and you’ll probably hear about the last time the alert came in. The difference isn’t luck. It’s geography, and it’s written down on a state map most homeowners have never looked at.
What the High Fire Threat District map is
The California Public Utilities Commission adopted its statewide fire threat map on January 19, 2018. It was developed by a utility mapping panel and reviewed by an independent team chaired by CAL FIRE. The map sorts areas served by overhead power lines into tiers:
- Tier 2: areas at higher risk from utility-associated wildfires
- Tier 3: areas at extreme risk
Tiers 2 and 3, along with Tier 1 High Hazard Zones from the state’s tree mortality map, make up the High Fire Threat District, or HFTD. Utilities apply stricter safety rules in these zones, and they’re the areas where SDG&E is most likely to de-energize lines during Santa Ana winds. The CPUC explains the map on its fire threat maps page.
How to look up your address
The CPUC publishes an interactive Fire Threat Map. Open it, click the magnifying glass icon, type your address and look at the shading around your home. Tier boundaries don’t follow city limits or ZIP codes, so two homes in the same neighborhood can land in different zones. Check your own address rather than your neighbor’s.
Why inland neighborhoods carry more risk
Inland North County and the I-15 corridor sit where Santa Ana winds funnel through canyons into chaparral-covered hills. That’s the setting for two of the largest fires in county history:
- The 2003 Cedar Fire burned more than 280,000 acres and destroyed 2,820 buildings. Within the City of San Diego, Scripps Ranch and Tierrasanta were hit hardest.
- The 2007 Witch Creek Fire, which merged with the Guejito Fire, burned nearly 198,000 acres, moving through Ramona, Rancho Bernardo and Poway toward Rancho Santa Fe. All 365 homes lost inside the City of San Diego were in Rancho Bernardo.
That history is why so many homeowners in Poway, Rancho Bernardo, Scripps Ranch, Rancho Santa Fe, Rancho Peñasquitos and Carmel Valley ask about battery backup installation. Parts of these communities sit near or inside fire-threat areas, and in early October 2026 SDG&E named Poway and Ramona among the areas that could see shutoffs.
What being in or near the HFTD means for you
- Shutoffs are more likely. SDG&E’s Public Safety Power Shutoffs target circuits in high-risk areas. Alerts typically start about 48 hours ahead, and shutoffs can run from several hours to multiple days.
- You may qualify for help with backup power. SDG&E’s 2026 Generator Assistance Program offers rebates toward a fuel generator or portable power station to customers in Tier 2 or Tier 3 areas who have experienced at least one PSPS.
- Planning ahead pays off. A battery installed before fire season is ready for the first watch notice. One installed in the middle of it may not be.
Backup for larger inland homes
Homes in Poway, Rancho Santa Fe and Rancho Bernardo often have bigger loads than a typical coastal house: central air, pool equipment, EV chargers, and on some rural lots, a well pump. That changes how backup should be designed.
Start by choosing what to back up. There are two approaches:
- Partial backup puts essential circuits (refrigerator, lights, internet, a few outlets, a well pump) on a dedicated backup panel. It stretches a battery further.
- Whole-home backup keeps everything on the battery. Tesla says a Powerwall 3 system can provide whole-home backup to most homes, but large loads like pool pumps and central AC will drain it faster.
Then size the storage. Each Tesla Powerwall 3 stores 13.5 kWh and delivers up to 11.5 kW continuously, with a built-in solar inverter that lets your panels recharge it during the day. A single system can grow to as many as seven units (up to four Powerwall 3s plus up to three Powerwall 3 Expansions), which gives a large home room to cover a multi-day shutoff. Tesla’s system design guide walks through the options.
Motor loads deserve a look. Well pumps and air conditioners draw a surge when they start. The Powerwall 3 is rated for that kind of starting current (185 A locked rotor, per Tesla’s datasheet), but your installer should check each motor load against the design rather than assume.
Solar is what makes it multi-day. Without panels, a battery is a countdown. With them, every sunny day of the shutoff refills the battery, which is why inland homes in fire-prone areas get the most out of pairing the two.
Know your tier before the next watch
Look up your address on the CPUC map, then decide what you’d want running if SDG&E called a shutoff tomorrow. If you’re in or near the HFTD, Stellar Solar can design solar and battery backup around your home’s real loads and your neighborhood’s shutoff history. Stellar Solar has been San Diego’s trusted solar installer since 1998, A+ rated with the BBB and a repeat winner of San Diego’s Best Solar in the Union-Tribune Readers Poll. Call 866.787.6527 for a free evaluation, or get your free quote here.
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