SDMap-doton-Sinai, 2004
Sinai’s story
135 years in pictures
Census counts: 216 in 1920, 99 in 2020. The archive holds 1 old photo or paper going back to 2004 and 2 maps from 1968 on.
- 1891Sinai is settled
SinaiSD
A town of 102, settled in 1891.
Population
102
2025 Census estimate · +8.5% since 2020
Median home value
$89K
Census ACS
Household income
$57K
median
Median age
24.9
years
Land area
0 sq mi
Is Sinai a good place to live?
No town among the 36 in South Dakota we compare has a higher mean commuting time than Sinai. Sinai has fewer than 1,000 residents, too few for fair grades; the figures below are still real.
Small town
102 people, and everyone knows the way
In a town this size, neighbors are the best guide. Ask them anything.
Nearby towns
Getting set up
The full setup list →Moving to Sinai: who provides what
Who provides power, water and the rest in Sinai, and how to reach them.
PowerSioux Valley SW Elec Coop13.9¢/kWh · EIA 2025HIFLD · EIA
WaterKingbrook I Rural Water SystemNo health-based violations in 5 years · EPAEPA
Internet1 providers100% of addresses get 100/20 MbpsFCC
Trash & dumpNot on file yetWe don’t have Sinai’s trash rules yet
Register to voteIn personSouth Dakota has no online registration; you can register in person until 15 days before Election Day or by mail (received 15 days before).vote.govWho runs elections hereBrookings County AuditorBrookings County; contacts on the Handbook page.FVAP, Jul 2023
ZIP code5706157061 100%Census 2020
EPA SDWIS (Oct 9, 2026) · HIFLD + EIA-861 2025 · Census 2020 ZCTAs · NCES 2024–25 · registration: vote.gov, updated Aug 3, 2026.
The data
Ordered by what stands out in Sinai.
Who lives here
More children than South Dakota overall
College graduates make up nearly a quarter of adults 25 and older, against 32% across South Dakota. Children under 18 are 44% of residents (24% statewide); people 65 and older are 3% of residents (18% statewide). Sinai has grown 8.5% since 2020, to 102 residents in the Census Bureau’s 2025 estimate.
24.9median age · SD 38
SinaiSouth DakotaUnited States
Ages · share of residents
42%
Education · adults 25 and older
No diploma23%
High school39%
Some college15%
Associate’s1%
Bachelor’s21%
Graduate2%
Women and men · all residents
Somewhere between 22% and 71% women
The Census survey reached too few of Sinai’s residents to say more: its margin here is ±24.5 points. Across South Dakota, 49.2% of residents are women.
| Sinai | SD | U.S. | |
|---|---|---|---|
| Under 10 | 41.9% | 13.1% | 11.6% |
| 10 to 17 | 1.9% | 11.2% | 10.3% |
| 18 to 24 | 7% | 9.3% | 9.1% |
| 25 to 34 | 13.5% | 12.6% | 13.7% |
| 35 to 44 | 16.7% | 12.6% | 13.2% |
| 45 to 54 | 10.7% | 10.7% | 12.2% |
| 55 to 64 | 5.1% | 12.6% | 12.7% |
| 65 to 74 | 2.3% | 11% | 10.2% |
| 75 and older | 0.9% | 7% | 7% |
| No diploma | 22.6% | 6.8% | 10.4% |
| High school | 38.7% | 29% | 26% |
| Some college | 15.1% | 19.9% | 19.1% |
| Associate’s | 0.9% | 12.3% | 8.8% |
| Bachelor’s | 20.8% | 21.9% | 21.6% |
| Graduate | 1.9% | 10% | 14.1% |
Census population estimates, 2025 · U.S. Census Bureau · ACS 2020-2024 5-year estimates · in a town of 100, single groups can be off by several points
36″snow a winter
Typical low → high °F
Winter8–26°
Spring33–54°
Summer58–80°
Fall35–57°
Oct 2
typical first frost
May 3
typical last frost
+0.7°
vs. the 20th-century average
NOAA U.S. Climate Normals, 1991–2020
Health
How healthy Sinai is
Among adults 18 to 64 in Sinai, 6.2% have no health insurance, below both the South Dakota town median (8.4%) and the median of U.S. towns (8.1%). Against the South Dakota average, Sinai comes out ahead on 8 CDC measures out of 26, and behind on 1. The share of adults in Sinai who report frequent mental distress: 13%. Only 3 of the 36 South Dakota towns we compare have a lower share of adults who smoke cigarettes than Sinai.
| Sinai | South Dakota towns | U.S. towns | |
|---|---|---|---|
| Frequent mental distress (CDC PLACES) | 13% | 15% | 17% |
| Sleep under 7 hours (CDC PLACES) | 29% | 30% | 36% |
| Get no exercise (CDC PLACES) | 19% | 22% | 25% |
| Smoke cigarettes (CDC PLACES) | 12% | 14% | 14% |
26 measures vs. South Dakota
8 better17 too close to call1 worse
| What stands out | Sinai | SD |
|---|---|---|
| Fewer uninsured adults | 6.2% | 8.8% |
| Fewer smokers | 11.5% | 15.2% |
| More adults who have had cancer | 10.9% | 9.2% |
Brookings Health System
14.3 mi away · emergency room
3 of 3
care shortages: primary care, dental, mental health
CDC PLACES 2025 · modeled estimates for adults · CMS · HRSA
Natural hazards
Sinai faces a moderate natural-hazard risk, led by inland flooding
Sinai’s risk rating from FEMA is 57 of 100, where South Dakota’s towns sit at 54 of 100 and U.S. towns at 44 of 100. Of the losses FEMA expects in the town, 49% come from inland flooding and 19% from tornadoes.
57risk score of 100
FEMA risk score
Inland floodingTornadoesCold waves
FEMA National Risk Index · OpenFEMA
Keep exploring
Everything we know about Sinai
17pages on Sinai
The big questions
Out and about
The story
After high school
Colleges nearby
2 within 15 miles of the center of Sinai
Institute of Lutheran TheologyUniversity or college · Private nonprofit · Brookings13.4 miSouth Dakota State UniversityUniversity or college · Public · Brookings13.9 mi$9,299 in-state tuition
About 0 of every 100 Sinai residents are enrolled in college, against 5 across South Dakota.
About Sinai
Town in South Dakota, United States
Sinai ( SY-nee-eye) is a town in Brookings County, South Dakota, United States. The population was 99 at the 2020 census.
From Wikipedia, licensed CC BY-SA 4.0 · facts via Wikidata (CC0)
- Area
- 0.4 sq mi
- Elevation
- 1,781 ft
- ZIP code
- 57061
- Area code
- 605
Questions about Sinai
Short answers, built from the data on this page.
Is Sinai, SD a good place to live?
Sinai has fewer than 1,000 residents, too few for fair grades; the figures below are still real.