PowerOutageHistory
Reliability Grade
A
Top tier
2019-2025
South Dakota

Buffalo CountyPower Outage History

20192025 · South Dakota
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What this grade means

(How grades are calculated)

Top 20% most reliable nationally — infrequent, short outages. This county ranks in the most reliable fifth of all US counties in our dataset, based on 12 years of real DOE outage records: outages happen less often here, and when they do occur they tend to be resolved quickly compared to the rest of the country. Baseline outage risk is low, though a severe local storm can still occasionally cause a longer-than-usual outage regardless of the long-term track record.

Takeaway
Low outage risk
Reliability Rank
Fuller bar = more reliable
Nationwide94th pct
In South Dakota#13 of 65
See full South Dakota rankings →
Total events
63
Recorded 2019–2025
Avg duration
2.0 hrs
Per outage event
Longest outage
8 hrs
Single worst event on record
Customers served
1,239
Utility customers in county

Outages by year

Outages by month (seasonality)

Worst outage events on record

DateDurationCustomers affectedCause
Apr 19, 20211 hrs639 (52%)Unnamed event
Sep 16, 20203 hrs633 (51%)Unnamed event
Jul 20, 2021<1 hr482 (39%)Drought
Jul 22, 20212 hrs482 (39%)Drought
Sep 15, 20202 hrs165 (13%)Unnamed event

Was There an Outage on a Specific Date?

Pick a date to see whether a power outage was recorded for Buffalo County, South Dakota that day.

Over the 7 years from 2019 to 2025, Buffalo County recorded 63 distinct power outage events, averaging 2.0 hours per event.

The single worst outage on record in Buffalo County started April 19, 2021, lasting 1 hours and leaving up to 639 customers without power (52% of the county) at its peak.

December has historically been the worst month for outages in Buffalo County, with 11 events recorded during that month across the dataset.

Based on this history, Buffalo County earns a Reliability Grade of A, placing it in the 94th percentile nationally for grid reliability (higher percentile = more reliable).

Similar counties in South Dakota

Counties with the closest reliability grade and national percentile to Buffalo County.

CountyGradeNational percentile
Walworth CountyA94th
Campbell CountyA93rd
Potter CountyA94th
Edmunds CountyA93rd
Stanley CountyA93rd

Most reliable counties nationally

The top 3 counties nationally by reliability grade and percentile.

CountyStateGradeNational percentile
Clay CountySouth DakotaA100th
Clearwater CountyMinnesotaA99th
Limestone CountyAlabamaA99th

Least reliable counties nationally

The bottom 3 counties nationally by reliability grade and percentile.

FAQ

How often does power go out in Buffalo County?

Between 2019 and 2025, Buffalo County recorded 63 outage events, averaging 2.0 hours each.

What is Buffalo County's reliability grade?

Buffalo County has a Reliability Grade of A, in the 94th national percentile.

What was the worst power outage in Buffalo County?

The worst outage on record started April 19, 2021, lasting 1 hours and affecting up to 639 customers.

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Data: ORNL EAGLE-I Recorded Electricity Outages (2014–2025), CC BY 4.0. Storm names: NOAA Storm Events Database. Last data refresh: 2025. See methodology.