California Power Outage Season
When outages happen most in California, and what to expect.
October is historically California's busiest month for recorded power outages, part of a summer season (June–August) that accounts for about 28% of all recorded outages statewide, averaging 4.3 hours per event. 24 of California's 58 tracked counties currently carry a Reliability Grade of F.
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California outages by month
Total recorded events and average duration per event, summed across every tracked county in California.
Peak season insight
California's outage season runs June–August, accounting for 28% of all recorded outages. October has the highest frequency.
Month-by-month data table
| Month | Events | Avg duration |
|---|---|---|
| January | 9,567 | 5.4 hrs |
| February | 8,984 | 5.9 hrs |
| March | 10,334 | 4.4 hrs |
| April | 9,568 | 3.7 hrs |
| May | 10,621 | 4.1 hrs |
| June | 12,127 | 3.4 hrs |
| July | 12,239 | 4.6 hrs |
| August | 12,384 | 4.6 hrs |
| September | 11,480 | 4.5 hrs |
| October | 13,344 | 4.1 hrs |
| November | 10,358 | 3.8 hrs |
| December | 10,903 | 5.2 hrs |
This month in California
October has historically recorded 13,344 outage events across California, above the state's typical monthly average. Outages that start in October have averaged 4.1 hours.
Main causes by season
Named storms behind California's worst recorded outages, from the NOAA Storm Events Database.
Winter (December–February)
- Heavy Rain
- Dense Fog
- Heavy Snow
- High Wind
- Flood
Spring (March–May)
- Blizzard
- Drought
- High Wind
- Strong Wind
- Heavy Snow
Summer (June–August)
- Drought
- Wildfire
- Excessive Heat
- Flood
- Lightning
Fall (September–November)
- Wildfire
- High Wind
- Strong Wind
- Drought
- Heavy Rain
California's worst outage events on record
The five largest outages in California by duration and customers affected.
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Jan 8, 2025 | 261 hrs | 1,717,886 (45%) | High Wind |
| Jan 8, 2023 | 137 hrs | 294,707 (45%) | Drought |
| Jan 1, 2023 | 130 hrs | 175,559 (27%) | Drought |
| Feb 4, 2024 | 104 hrs | 207,107 (32%) | Strong Wind |
| Feb 4, 2024 | 137 hrs | 145,840 (17%) | Strong Wind |
Highest-risk counties in California
Lowest reliability percentile among California's tracked counties.
| County | Grade | National percentile |
|---|---|---|
| Sierra County | F | 0th |
| Plumas County | F | 1st |
| Mariposa County | F | 1st |
| Calaveras County | F | 1st |
| Amador County | F | 1st |
Live weather alerts for California
Extreme Heat Warning
Extreme Heat Warning issued October 1 at 12:29AM PDT until October 8 at 8:00PM PDT by NWS San Diego CA
Read the official NWS alert →Extreme Heat Warning
Extreme Heat Warning issued October 1 at 12:29AM PDT until October 8 at 8:00PM PDT by NWS San Diego CA
Read the official NWS alert →Extreme Heat Warning
Extreme Heat Warning issued October 1 at 12:29AM PDT until October 8 at 8:00PM PDT by NWS San Diego CA
Read the official NWS alert →Extreme Heat Warning
Extreme Heat Warning issued October 1 at 12:29AM PDT until October 8 at 8:00PM PDT by NWS San Diego CA
Read the official NWS alert →Extreme Heat Warning
Extreme Heat Warning issued October 1 at 12:29AM PDT until October 8 at 8:00PM PDT by NWS San Diego CA
Read the official NWS alert →These live alerts come from the National Weather Service. They are public-safety information, not an outage prediction.
California power outage FAQ
When do power outages happen most in California?
October is historically the busiest single month for recorded outages in California, and Summer (June–August) accounts for about 28% of all recorded outages across the state.
How long do power outages in California typically last?
Across California's tracked counties, the average recorded outage lasts about 4.3 hours, though individual events -- especially named storms -- can run much longer.
Which counties in California have the highest outage risk?
Sierra County, Plumas County, Mariposa County, Calaveras County, Amador County currently rank lowest for reliability in California. See each county's page for its full history.
Does this page predict a power outage in California?
No. It describes patterns in recorded county-level outage history, not a guaranteed future event. Check the live National Weather Service alerts below for current conditions.
Prepare for California's outage season
Sized for California's recorded outage frequency and duration.
