Union, SC frost dates
From NOAA weather station Union 8 S (USC00388786), elevation 480 ft. The station is named for Union, and its coordinates are 8.5 miles from the Census Bureau’s internal point for Union city.
Summary
In the 1991–2020 record, the median last spring freeze (32°F) at Union 8 S is Apr 6 and the median first fall freeze is Oct 30, for a typical freeze-free season of 207 days. In about 1 year in 10 the last spring freeze comes after Apr 21, and in about 1 year in 10 the first fall freeze arrives by Oct 17. The station averages 87 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 11 days later than the state median (Mar 26), the median first freeze is 10 days earlier than the state median (Nov 9), and the growing season ranks #93 of 103 by length (longest = #1). The spread between the 90% and 10% spring dates is 31 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) | Apr 3 | Apr 18 | May 4 | Oct 10 | Oct 22 | Nov 2 | 165 / 186 / 206 |
| 32°F (freeze) | Mar 21 | Apr 6 | Apr 21 | Oct 17 | Oct 30 | Nov 12 | 188 / 207 / 229 |
| 28°F (hard freeze) | Mar 6 | Mar 26 | Apr 11 | Oct 26 | Nov 9 | Nov 29 | 207 / 230 / 256 |
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 Union
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 Union 8 S: Whitmire (8 mi), Buffalo (8 mi), Union (8 mi), Cross Anchor (11 mi).
Nearby stations
- Santuck, SC — 8 mi; median last freeze Apr 4, first freeze Nov 1
- Clinton, SC — 16 mi; median last freeze Mar 29, first freeze Nov 4
- Laurens, SC — 22 mi; median last freeze Apr 1, first freeze Nov 5
- Newberry, SC — 22 mi; median last freeze Mar 31, first freeze Nov 7
- Spartanburg 3 SSE, SC — 25 mi; median last freeze Apr 8, first freeze Nov 1
About this station’s data
- Station ID: USC00388786 · Latitude 34.6053, longitude -81.6631 · Elevation 146 m (480 ft)
- NOAA completeness flag: R — Representative: meets WMO standards for 10 or more years; gaps filled from surrounding stations. Years of data used: 21.
- Source file: USC00388786.csv (NOAA NCEI 1991–2020 annual/seasonal normals).
Raw values from the NOAA file (32°F)
| Field | Value |
|---|---|
ANN-TMIN-PRBLST-T32FP10 | 04/21 |
ANN-TMIN-PRBLST-T32FP50 | 04/06 |
ANN-TMIN-PRBLST-T32FP90 | 03/21 |
ANN-TMIN-PRBFST-T32FP10 | 10/17 |
ANN-TMIN-PRBFST-T32FP50 | 10/30 |
ANN-TMIN-PRBFST-T32FP90 | 11/12 |
ANN-TMIN-PRBGSL-T32FP10 | 229.0 |
ANN-TMIN-PRBGSL-T32FP50 | 207.0 |
ANN-TMIN-PRBGSL-T32FP90 | 188.0 |