Johnston, SC frost dates
From NOAA weather station Johnston 4 SW (USC00384607), elevation 629 ft. The station is named for Johnston, and its coordinates are 4.6 miles from the Census Bureau’s internal point for Johnston town.
Summary
In the 1991–2020 record, the median last spring freeze (32°F) at Johnston 4 SW is Mar 26 and the median first fall freeze is Nov 8, for a typical freeze-free season of 228 days. In about 1 year in 10 the last spring freeze comes after Apr 11, and in about 1 year in 10 the first fall freeze arrives by Oct 25. The station averages 66 nights per year with a low of 32°F or colder.
Compared with the median of 103 South Carolina stations in this dataset, the median last freeze here is the same day as the state median (Mar 26), the median first freeze is 1 day earlier than the state median (Nov 9), and the growing season ranks #56 of 103 by length (longest = #1). The spread between the 90% and 10% spring dates is 36 days, a measure of how variable spring is here.
Freeze probability table
| Threshold | Last spring occurrence | First fall occurrence | Season length (days) 90% / 50% / 10% | ||||
|---|---|---|---|---|---|---|---|
| Early (90% chance of a later freeze) | Median (50%) | Cautious (10% chance of a later freeze) | Early (10% chance by then) | Median (50%) | Late (90% chance by then) | ||
| 36°F (light frost possible) | Mar 21 | Apr 7 | Apr 22 | Oct 16 | Oct 29 | Nov 11 | 185 / 204 / 226 |
| 32°F (freeze) | Mar 6 | Mar 26 | Apr 11 | Oct 25 | Nov 8 | Nov 28 | 203 / 228 / 254 |
| 28°F (hard freeze) | Feb 18 | Mar 13 | Mar 31 | Nov 4 | Nov 19 | Dec 12 | 229 / 254 / 285 |
Read the spring “Cautious” column as the safer planting date: only about 1 year in 10 has a freeze after it. NOAA computes these from daily minimum temperatures at the station; your yard can differ, especially in low spots or at a different elevation.
Planting calendar for Johnston
Pick how much frost risk you accept. The calendar applies generic, extension-published timing rules to this station’s dates. See the rules and sources.
| Crop | Start seeds indoors | Plant outdoors (spring) | Latest fall planting (est.) | Days to harvest |
|---|
Fall estimates count back from the median first fall freeze (32°F for tender crops, 28°F hard freeze for cool-season crops) by the longer days-to-harvest figure. These are rough planning aids, not recommendations for any specific variety; check seed packets and your county extension office.
Towns that use this station as their nearest
Census places within 15 miles whose closest station in this dataset is Johnston 4 SW: Trenton (2 mi), Johnston (5 mi), Ward (9 mi).
Nearby stations
- Edgefield 2.2 ENE, SC — 3 mi; median last freeze Mar 16, first freeze Nov 13
- Graniteville 1.2 NE, SC — 14 mi; median last freeze Apr 9, first freeze Nov 1
- Saluda, SC — 16 mi; median last freeze Mar 31, first freeze Nov 4
- Aiken 2 E, SC — 18 mi; median last freeze Mar 19, first freeze Nov 14
- Batesburg, SC — 20 mi; median last freeze Mar 20, first freeze Nov 18
About this station’s data
- Station ID: USC00384607 · Latitude 33.7756, longitude -81.8444 · Elevation 192 m (629 ft)
- NOAA completeness flag: R — Representative: meets WMO standards for 10 or more years; gaps filled from surrounding stations. Years of data used: 22.
- Source file: USC00384607.csv (NOAA NCEI 1991–2020 annual/seasonal normals).
Raw values from the NOAA file (32°F)
| Field | Value |
|---|---|
ANN-TMIN-PRBLST-T32FP10 | 04/11 |
ANN-TMIN-PRBLST-T32FP50 | 03/26 |
ANN-TMIN-PRBLST-T32FP90 | 03/06 |
ANN-TMIN-PRBFST-T32FP10 | 10/25 |
ANN-TMIN-PRBFST-T32FP50 | 11/08 |
ANN-TMIN-PRBFST-T32FP90 | 11/28 |
ANN-TMIN-PRBGSL-T32FP10 | 254.0 |
ANN-TMIN-PRBGSL-T32FP50 | 228.0 |
ANN-TMIN-PRBGSL-T32FP90 | 203.0 |