South Dakota · Central Time
605 Area Code
Area code 605 is in South Dakota, serving the entire state of South Dakota. It is in the Central Time zone (part of its territory observes Mountain Time).
Last updated October 1, 2026 · Source: NANPA
Where is the 605 area code?
605 is a South Dakota area code covering the entire state of South Dakota. In the wider directory it sits in the Midwest region.
Cities in the 605 area code
- Sioux Falls
- Rapid City
- Aberdeen
- Brookings
- Watertown
- Mitchell
- Yankton
- Pierre
- Huron
- Brandon
- Spearfish
- Vermillion
- Box Elder
Counties served by 605
Minnehaha County, Pennington County, Lincoln County, Brown County, Brookings County, Codington County, Meade County, Lawrence County, Davison County and Yankton County.
Time zone note: Central in the east (Sioux Falls); west-river South Dakota is Mountain.
Dialing 605
Sioux Falls, SD is currently served by the single area code 605, with no overlay. Ten-digit dialing (area code + seven-digit number) always works and is increasingly the norm nationwide; some local calls may still connect with seven digits. If a future overlay is added, 10-digit dialing would become mandatory.
From outside the US, dial +1 605 followed by the seven-digit number.
History of the 605 area code
605 is one of the original area codes assigned in 1947, when AT&T and Bell Laboratories created the North American Numbering Plan and divided the country into the first 86 numbering plan areas. It has served the Sioux Falls area ever since.
Is 605 a scam or spam risk?
605 is a legitimate geographic area code, not a premium or toll line, so a call from it costs you nothing extra. That said, scammers frequently spoof real local area codes to look familiar on caller ID. A genuine 605 number on your screen is no guarantee the caller is in Sioux Falls, SD or trustworthy. See spam & scam-risk area codes for how spoofing works and how to respond.
Explore more
See every code in South Dakota, compare codes across the Midwest region, or view all Central Time codes. You can also browse the 6XX block or the complete numeric list of US area codes.
New to how this all works? Start with how area codes work, then read up on overlays, 10-digit dialing, and spam & scam-risk codes. To check another number, use the area code lookup tool.
Quick answers
605 area code FAQ
Where is the 605 area code?
The 605 area code is in South Dakota, covering the entire state of South Dakota, in the Midwest region.
What cities are in the 605 area code?
Cities in the 605 area code include Sioux Falls, Rapid City, Aberdeen, Brookings, Watertown, Mitchell, Yankton, Pierre, Huron and Brandon.
What time zone is 605 in?
605 is in the Central Time zone. Central in the east (Sioux Falls); west-river South Dakota is Mountain.
When did the 605 area code start?
605 went into service on January 1, 1947 as one of the original 1947 North American area codes.
Do I have to dial 10 digits for 605?
Ten-digit dialing always works, and many areas now require it; some local calls in this area may still connect with seven digits.
Is 605 a toll-free or premium code?
No. 605 is a standard geographic area code, so calling it costs the same as any local or long-distance call on your plan. Toll-free calls use 800, 888, 877, 866, 855, 844 or 833.