Does a wet El Niño winter mean fire season is over in San Diego?
No — El Niño's rain mostly arrives December through March, and San Diego's most dangerous fire window is fall, when Santa Ana winds hit vegetation that's driest from late September to mid-November; expect Red Flag Warnings and possible SDG&E power shutoffs until the rains actually come.
- Riskiest window
- Late Sept – mid-Nov
- PSPS customer alerts
- 24–48 hrs ahead
- Generator rebate (eligible)
- $300 · $150 power station
- Evacuation zones
- Genasys Protect app
The short version
- Santa Ana winds blow from fall through early spring; fuels are driest from late September through mid-November (Rolinski et al., SDG&E/USFS).
- The NWS issues a Red Flag Warning for "an ongoing or imminent critical fire weather pattern."
- SDG&E starts monitoring for a Public Safety Power Shutoff 3–10 days out, alerts affected customers 24–48 hours ahead, and restores power only after daylight line inspections.
- SDG&E offers a $300 rebate on a fuel generator or $150 on a portable power station for eligible High Fire Threat District customers.
- Find your evacuation zone now in the Genasys Protect app — San Diego County uses it for evacuation warnings and orders.
It's natural to assume a record El Niño means a soggy, fireproof year. But look at the calendar. El Niño storms, if they come, mostly arrive after Christmas. Right now — late September into November — is when San Diego's vegetation is at its driest after a rainless summer, and it's the heart of Santa Ana season. San Diego's worst fires, including Cedar in 2003 and Witch in 2007, happened in exactly this window.
Fire season and rain season overlap less than you'd think
Santa Ana timing and fuel dryness from Rolinski et al. (2015), "The Santa Ana Wildfire Threat Index"; rain months from NWS normals.
What a Santa Ana actually is
A Santa Ana is an offshore windstorm: air from the high deserts flows downhill toward the coast, compressing and warming as it drops, and arrives hot and extraordinarily dry. The research that underpins today's Santa Ana Wildfire Threat Index describes them as downslope winds from the northeast to east, typically with temperatures of 18°C (64°F) or more and relative humidity of 20% or less. During the 2007 Witch Creek Fire, humidity fell to about 5%. It's also why San Diego's hottest days often come in September and October, not July.
Three alerts, three different meanings
| Red Flag Warning | Public Safety Power Shutoff | Evacuation warning / order | |
|---|---|---|---|
| Who issues it | National Weather Service | SDG&E | Sheriff and fire agencies, by zone |
| What it means | Critical fire weather is happening or imminent | Power cut in high-risk areas so lines can't start a fire | Warning: get ready or leave early. Order: leave now |
| What you do | No sparks: no mowing dry grass, no towing with dragging chains, no outdoor flames | Charge devices, plan for medical equipment, find the nearest Community Resource Center | Know your zone in Genasys Protect before you need it |
| Verdict | — | — | The only one that tells you to leave |
How an SDG&E power shutoff unfolds
PSPS timeline
SDG&E, Public Safety Power Shutoffs.
Shutoffs target SDG&E's High Fire Threat District — largely the backcountry and the eastern edges of the metro area — not the coast. During one, SDG&E opens Community Resource Centers with free Wi-Fi, water, ice, snacks and device charging. Customers who rely on powered medical devices should enroll in SDG&E's Medical Baseline program, which adds in-person contact attempts during a PSPS.
- 01
Update your SDG&E contact info
Through My Energy Center or the Alerts by SDG&E app, so PSPS notices actually reach your phone.
- 02
Look up your evacuation zone
Open Genasys Protect and search your address. Write the zone name down.
- 03
Sign up for AlertSanDiego
The County's emergency alerts cover fire, flood and evacuation.
- 04
Pack a go-bag once
Medications, documents, chargers, water, pet supplies. The same bag works for a flood.
KEEP READING
SOURCES
Everything above traces back to one of these. Follow them — if one has changed and we haven't, that's our mistake, not yours.
- PrimaryPublic Safety Power Shutoffs
San Diego Gas & Electric · 2026-09-29
Notification timeline, CRCs, Medical Baseline, generator rebates, restoration
National Weather Service · 2026-09-29
Red Flag Warning and Fire Weather Watch definitions
- BackgroundThe Santa Ana Wildfire Threat Index
Rolinski et al., Weather and Forecasting (hosted by SDG&E) · 2015
Definition, season, fuel dryness late Sept–mid Nov, Witch Fire conditions
- PrimaryEvacuation
County of San Diego Office of Emergency Services · 2026-09-29
Genasys Protect for zone lookup
CalMatters · 2026-08-01