Johnston, South Carolina Weather
Cicadas claim the scorching afternoon. Day 15 of summer. Read this microseason across nine climate regions →
Johnston weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Light Drizzle12%0.02″96°74°—
- MondayJul 6Heavy Showers31%0.30″94°76°-2°
- TuesdayJul 7Overcast16%—98°74°+4°
- WednesdayJul 8Light Drizzle11%—100°73°+2°
- ThursdayJul 9Overcast——100°75°0°
- FridayJul 10Partly Cloudy12%—103°76°+3°
- SaturdayJul 11Partly Cloudy28%—101°77°-2°
AQI 55 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 14.8 µg/m³ (AQI 62) with a 0.94 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 44 now. With UV 3.8 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 22 around 1 PM.
- Present
- AQI 44
- UV peak
- 3.8 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 22
PM × Wind × Precip
PM2.5 at 14.8 µg/m³ (AQI 62) with a 0.94 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.94
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:41 PM
- Moonset
- 11:40 AM
- In sign
- ♓︎ Pisces
Cicadas claim the scorching afternoon
Johnston at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: March 10 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 29832
16-Day Forecast — Johnston
- Sun96°74°12%
- Mon94°76°31%
- Tue98°74°16%
- Wed100°73°11%
- Thu100°75°9%
- Fri103°76°12%
- Sat101°77°28%
- Sun101°76°35%
- Mon97°75°31%
- Tue98°71°22%
- Wed108°70°16%
- Thu89°71°30%
- Fri89°70°39%
- Sat95°70°45%
- Sun98°76°35%
- Mon97°76°42%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Johnston
SPC has placed Johnston in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
ZIP codes in Johnston
- 29832