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Will it freeze in Shelley in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 30°F (Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST).
Tonight: forecast low 30°F. Freeze.
NWS forecast period: Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST.
7 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 30°F Freeze · Areas Of Fog
- Fri, Nov 6 28°F Hard freeze · Partly Cloudy
- Sat, Nov 7 30°F Freeze · Mostly Clear
- Sun, Nov 8 33°F Frost possible · Partly Cloudy
- Mon, Nov 9 35°F Frost possible · Mostly Cloudy
- Tue, Nov 10 35°F Frost possible · Mostly Clear
- Wed, Nov 11 35°F Frost possible · Partly Cloudy
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Shelley
The median first fall hard-freeze date (28°F) is October 2, from NOAA’s 1991–2020 Climate Normals at Idaho Falls Fanning Field. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | May 28 · Jun 14 · Jul 2 | Aug 20 · Sep 5 · Sep 22 | 79 days |
| 32°F freeze | May 7 · May 23 · Jun 13 | Sep 1 · Sep 20 · Oct 4 | 114 days |
| 28°F hard freeze | Apr 23 · May 7 · May 23 | Sep 15 · Oct 2 · Oct 16 | 146 days |
Average high temperature by month
1991–2020 normals at Idaho Falls Fanning Field
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Shelley, ID come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Idaho Falls Fanning Field (station USW00024145, elevation 4,729 ft), 9.9 mi from Shelley. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Shelley
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Idaho Falls, ID | 8.7 mi | May 9 | Oct 1 |
| Ammon, ID | 11 mi | May 9 | Oct 1 |
| Blackfoot, ID | 17 mi | May 5 | Oct 3 |
| Rigby, ID | 23 mi | May 9 | Oct 5 |
| Rexburg, ID | 35 mi | May 12 | Sep 24 |
| Chubbuck, ID | 35 mi | May 16 | Oct 2 |
| Pocatello, ID | 39 mi | May 2 | Oct 11 |
| Jackson, WY | 68 mi | Jun 20 | Aug 31 |
| Preston, ID | 89 mi | May 16 | Sep 28 |
| Rupert, ID | 94 mi | May 6 | Oct 6 |
Frequently asked questions
When is the last frost in Shelley?
On average, the last spring frost (32°F) in Shelley is around May 23. In about 1 year in 10 it comes after June 13, and in 9 years in 10 it comes after May 7.
When is the first frost in Shelley?
The first fall frost (32°F) usually arrives around September 20. There’s a 10% chance of a freeze by September 1 and a 90% chance by October 4.
Can it frost in Shelley after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after June 14.
What growing zone is Shelley?
Shelley is in USDA Plant Hardiness Zone 5b (average annual extreme minimum temperature −15 to −10°F), based on the 2023 USDA map for ZIP code 83274. See growing zones in Idaho.
More: all Idaho frost dates · Idaho growing zones · frost vs. freeze