South Dakota Power Outage Season
When outages happen most in South Dakota, and what to expect.
July is historically South Dakota's busiest month for recorded power outages, part of a summer season (June–August) that accounts for about 38% of all recorded outages statewide, averaging 3.5 hours per event.
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South Dakota outages by month
Total recorded events and average duration per event, summed across every tracked county in South Dakota.
Peak season insight
South Dakota's outage season runs June–August, accounting for 38% of all recorded outages. July has the highest frequency.
Month-by-month data table
| Month | Events | Avg duration |
|---|---|---|
| January | 545 | 2.8 hrs |
| February | 422 | 3.2 hrs |
| March | 556 | 3.1 hrs |
| April | 789 | 3.2 hrs |
| May | 942 | 3.9 hrs |
| June | 1,254 | 3.8 hrs |
| July | 1,447 | 3.4 hrs |
| August | 1,086 | 2.7 hrs |
| September | 843 | 2.5 hrs |
| October | 802 | 3.3 hrs |
| November | 609 | 3.0 hrs |
| December | 793 | 4.5 hrs |
This month in South Dakota
October has historically recorded 802 outage events across South Dakota, below the state's typical monthly average. Outages that start in October have averaged 3.3 hours.
Main causes by season
Named storms behind South Dakota's worst recorded outages, from the NOAA Storm Events Database.
Winter (December–February)
- Drought
- Winter Weather
- Extreme Cold/Wind Chill
- High Wind
- Winter Storm
Spring (March–May)
- Blizzard
- Flood
- Thunderstorm Wind
- Heavy Snow
- Hail
Summer (June–August)
- Excessive Heat
- Drought
- Thunderstorm Wind
- Flood
- Tornado
Fall (September–November)
- Drought
- Blizzard
- Winter Storm
- High Wind
- Thunderstorm Wind
South Dakota's worst outage events on record
The five largest outages in South Dakota by duration and customers affected.
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Dec 18, 2025 | 121 hrs | 25,159 (27%) | High Wind |
| May 12, 2022 | 68 hrs | 16,409 (14%) | Thunderstorm Wind |
| Dec 18, 2025 | 159 hrs | 5,295 (86%) | High Wind |
| Jul 5, 2022 | 29 hrs | 23,986 (20%) | Thunderstorm Wind |
| May 12, 2022 | 99 hrs | 3,402 (38%) | High Wind |
Highest-risk counties in South Dakota
Lowest reliability percentile among South Dakota's tracked counties.
| County | Grade | National percentile |
|---|---|---|
| Harding County | D | 21st |
| Perkins County | D | 29th |
| Custer County | D | 30th |
| Grant County | D | 31st |
| Marshall County | D | 37th |
Live weather alerts for South Dakota
There are no active National Weather Service alerts for South Dakota right now.
These live alerts come from the National Weather Service. They are public-safety information, not an outage prediction.
South Dakota power outage FAQ
When do power outages happen most in South Dakota?
July is historically the busiest single month for recorded outages in South Dakota, and Summer (June–August) accounts for about 38% of all recorded outages across the state.
How long do power outages in South Dakota typically last?
Across South Dakota's tracked counties, the average recorded outage lasts about 3.5 hours, though individual events -- especially named storms -- can run much longer.
Which counties in South Dakota have the highest outage risk?
Harding County, Perkins County, Custer County, Grant County, Marshall County currently rank lowest for reliability in South Dakota. See each county's page for its full history.
Does this page predict a power outage in South Dakota?
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 South Dakota's outage season
Sized for South Dakota's recorded outage frequency and duration.
