Johnston, SC Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Johnston, a town in Edgefield County, South Carolina.
Today
87°F
Patchy Fog then Chance Showers And Thunderstorms
Patchy fog before 9am, then a chance of showers and thunderstorms between 1pm and 4pm, then showers and thunderstorms likely. Partly sunny, with a high near 87. East wind 1 to 5 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Johnston
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Patchy Fog then Chance Showers And Thunderstorms | 1 to 5 mph E | 65% |
| Tonight | 69°F | Chance Showers And Thunderstorms then Mostly Cloudy | 0 to 3 mph E | 50% |
| Wednesday | 88°F | Patchy Fog then Chance Showers And Thunderstorms | 1 to 7 mph SE | 52% |
| Wednesday Night | 70°F | Chance Showers And Thunderstorms | 5 mph S | 40% |
| Thursday | 90°F | Partly Sunny then Chance Showers And Thunderstorms | 6 mph S | 53% |
| Thursday Night | 70°F | Chance Showers And Thunderstorms | 1 to 5 mph S | 53% |
| Friday | 91°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 1 to 5 mph S | 31% |
| Friday Night | 70°F | Chance Showers And Thunderstorms | 0 to 3 mph SE | 31% |
| Saturday | 91°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 0 to 5 mph SE | 24% |
| Saturday Night | 71°F | Slight Chance Showers And Thunderstorms | 1 to 5 mph S | 24% |
| Sunday | 91°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 3 mph SW | 39% |
| Sunday Night | 72°F | Chance Showers And Thunderstorms | 2 mph S | 39% |
| Monday | 92°F | Mostly Sunny then Chance Showers And Thunderstorms | 5 mph SW | 29% |
| Monday Night | 72°F | Chance Showers And Thunderstorms | 3 mph SW | 29% |
Forecast source: National Weather Service (api.weather.gov) for Johnston (33.833, -81.805). Updated through the day.
Growing snapshot for Johnston
Last spring frost
Mar 26
First fall frost
Nov 8
Growing season
228 days
Hardiness zone
8a
More local growing data for Johnston: nearby ZIP 29832 weather · frost dates · planting calendar · South Carolina frost dates
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Climate data from the nearest NOAA station, Johnston 4 Sw, Sc (5 mi from Johnston). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.