Frost dates for 83340Ketchum, ID
Frost is possible in any month near Ketchum, based on NOAA 1991-2020 records for the Ketchum Rs, ID station.
Frost is possible in any month. Even summer nights can drop to freezing at this station, so protect tender plants whenever cold nights are forecast.
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | — | — | 46 days | 100% |
| Frost / freeze (32°F) | — | — | 77 days | 100% |
| Hard freeze (28°F) | May 5 · May 28 · Jun 29 | Sep 3 · Sep 19 · Oct 5 | 112 days | 100% |
Where these dates come from
ZIP code 83340 is matched to the NOAA station Ketchum Rs, ID, 10.2 km away, at 5,890 ft elevation (1,810 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ketchum Rs, ID (used) | 5,890 ft | — | — |
| Bellevue, ID | 5,192 ft | May 13 | Oct 2 |
| Fairfield Rs, ID | 5,065 ft | Jun 8 | Sep 14 |
| Picabo, ID | 4,839 ft | Jun 16 | Sep 9 |
Frost dates near Ketchum
- Sun Valley, ID 83353 · last —, first —
- Hailey, ID 83333 · last May 13, first Oct 2
- Corral, ID 83322 · last —, first —
- Bellevue, ID 83313 · last May 13, first Oct 2
- Fairfield, ID 83327 · last Jun 8, first Sep 14
- Picabo, ID 83348 · last Jun 16, first Sep 9
- Hill City, ID 83337 · last Jun 16, first Sep 6
- Atlanta, ID 83601 · last Jun 16, first Sep 6
Frequently asked questions
- When is the last frost in Ketchum, ID?
- Frost is possible in any month at the nearest NOAA station (Ketchum Rs, ID), so there is no reliable average last frost date.
- When is the first frost in Ketchum, ID?
- Frost is possible in any month at the nearest NOAA station.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.