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Johnston, SC
Full City Profile · South Carolina · Edgefield County County
2.7
/5.0
C+
Fair
2,518
Population
961/sq mi density
$34,957
Median Income
$22,252 per capita
$100,400
Home Value
$145,103 Zillow
$803
Median Rent
33.3% income on rent
63°F
Avg Temperature
308 sunny days/yr
775
Violent Crime/100K
2,582 property/100K
C+
Overall
2.7 / 5.0
Fair overall score based on economy, affordability, safety and education
C+
Economy
2.6 / 5.0
$34,957 median income, 3.7% unemployment
A+
Affordability
5.0 / 5.0
$100,400 home value, $803/mo rent
F
Safety
1.0 / 5.0
775 violent crimes/100K (104% above avg)
C
Education
2.1 / 5.0
13.8% bachelor's degree or higher
Johnston enjoys a temperate climate with an average annual temperature of 63°F (17°C). Winters average 44°F in January while summers reach 81°F in July. The area gets 308 sunny days per year. Annual precipitation totals 48.5 inches. The area receives 1.0 inches of snow annually. Air quality is rated Good with a median AQI of 43.
Temperature
44°F Jan (7°C)
81°F Jul (27°C)
| Annual Average | 62.7°F |
| 16% above US avg | |
| January Average | 44°F (7°C) |
| July Average | 81°F (27°C) |
| Sunny Days | 308 days/yr |
Geography
| Elevation | 640 ft (195 m) |
| Area | 2.7 sq mi (6.9 km²) |
| Population Density | 961/sq mi |
| Coordinates | 33.8334°N, 81.8048°W |
| Timezone | America/New_York |
| County | Edgefield County County |
| Nearest Airport | Aiken Regional (AIK) 14 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 43.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0409 ppm |
| SO₂ (Sulfur Dioxide) | 0.16 ppb |
| PM2.5 (Fine Particles) | 8.9 μg/m³ |
Natural Hazard Risk
| Overall Risk | Very Low |
| Risk Score | 22.0 / 100 |
| Social Vulnerability | 54.7 / 100 |
| Community Resilience | 21.3 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Relatively Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Very Low |
| Hail | Relatively Low |
| Strong Wind | Relatively Low |
| Heat Wave | Relatively Low |
| Winter Weather | Very Low |
| Lightning | Relatively Low |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Low |
| Cold Wave | Relatively Low |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 44°F (7°C) | 4.8 in | Coldest |
| February | 46°F (8°C) | 4.0 in | |
| March | 54°F (12°C) | 4.8 in | Wettest |
| April | 61°F (16°C) | 3.2 in | |
| May | 69°F (20°C) | 3.6 in | |
| June | 76°F (25°C) | 4.3 in | |
| July | 81°F (27°C) | 4.7 in | Warmest |
| August | 78°F (26°C) | 4.3 in | |
| September | 73°F (23°C) | 3.5 in | |
| October | 62°F (17°C) | 3.4 in | |
| November | 53°F (12°C) | 3.0 in | Driest |
| December | 45°F (7°C) | 3.6 in |
Johnston has a seasonal temperature swing of 37°F / from 44°F in January to 81°F in July. Total annual precipitation is 47.2 inches, with March being the wettest month (4.8") and November the driest (3.0").