Johnston, SC Weather & Growing Conditions
Tonight
71°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 71. Northeast wind around 2 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 71°F | Slight Chance Showers And Thunderstorms | 2 mph NE | 22% |
| Saturday | 92°F | Mostly Sunny then Chance Showers And Thunderstorms | 5 mph NE | 32% |
| Saturday Night | 70°F | Chance Showers And Thunderstorms | 5 mph NE | 35% |
| Sunday | 88°F | Partly Sunny then Chance Showers And Thunderstorms | 3 mph NE | 36% |
| Sunday Night | 70°F | Chance Showers And Thunderstorms then Partly Cloudy | 2 mph E | 36% |
| Monday | 90°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 to 3 mph S | 47% |
| Monday Night | 69°F | Chance Showers And Thunderstorms | 3 mph E | 53% |
| Tuesday | 86°F | Showers And Thunderstorms Likely | 2 to 7 mph NE | 58% |
| Tuesday Night | 68°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 6 to 9 mph NE | 58% |
| Wednesday | 81°F | Chance Showers And Thunderstorms | 13 mph NE | 33% |
| Wednesday Night | 64°F | Chance Showers And Thunderstorms then Partly Cloudy | 9 to 13 mph NE | 33% |
| Thursday | 80°F | Mostly Sunny | 12 mph NE | 10% |
| Thursday Night | 63°F | Partly Cloudy | 6 to 10 mph NE | 8% |
| Friday | 80°F | Mostly Sunny | 9 mph N | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Johnston, SC
Last spring frost
Mar 26
First fall frost
Nov 8
Growing season
228 days
Hardiness zone
8a
Explore more for Johnston, SC: full frost dates · planting calendar · South Carolina frost dates
Climate data from the nearest NOAA station, Johnston 4 Sw, Sc (5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.