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Will it freeze in Rapid City in the next 7 nights?
No overnight lows at or below 32°F are forecast in Rapid City during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 34°F. Frost possible.
NWS forecast period: Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST.
1 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 34°F Frost possible · Partly Cloudy
- Fri, Nov 6 37°F Above 36°F · Mostly Clear
- Sat, Nov 7 39°F Above 36°F · Mostly Clear
- Sun, Nov 8 44°F Above 36°F · Mostly Clear
- Mon, Nov 9 39°F Above 36°F · Partly Cloudy
- Tue, Nov 10 41°F Above 36°F · Partly Cloudy
- Wed, Nov 11 43°F Above 36°F · Mostly Clear
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 Rapid City
The median first fall hard-freeze date (28°F) is October 18, from NOAA’s 1991–2020 Climate Normals at Rapid City WFO. 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 1 · May 15 · May 29 | Sep 19 · Oct 1 · Oct 14 | 137 days |
| 32°F freeze | Apr 20 · May 3 · May 17 | Sep 26 · Oct 8 · Oct 23 | 157 days |
| 28°F hard freeze | Apr 8 · Apr 22 · May 5 | Oct 3 · Oct 18 · Nov 1 | 178 days |
Average high temperature by month
1991–2020 normals at Rapid City WFO
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 Rapid City, SD come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Rapid City WFO (station USC00396948, elevation 3,379 ft), 0.4 mi from Rapid City. 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 Rapid City
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Box Elder, SD | 7.5 mi | May 12 | Oct 1 |
| Sturgis, SD | 27 mi | May 8 | Oct 3 |
| Spearfish, SD | 42 mi | May 12 | Oct 2 |
| Belle Fourche, SD | 52 mi | May 10 | Sep 30 |
| Gillette, WY | 114 mi | May 15 | Oct 1 |
| Alliance, NE | 137 mi | May 11 | Oct 3 |
| Douglas, WY | 142 mi | May 19 | Sep 23 |
| Pierre, SD | 145 mi | May 6 | Oct 3 |
| Torrington, WY | 147 mi | May 11 | Sep 29 |
| Scottsbluff, NE | 154 mi | May 8 | Oct 3 |
Frequently asked questions
When is the last frost in Rapid City?
On average, the last spring frost (32°F) in Rapid City is around May 3. In about 1 year in 10 it comes after May 17, and in 9 years in 10 it comes after April 20.
When is the first frost in Rapid City?
The first fall frost (32°F) usually arrives around October 8. There’s a 10% chance of a freeze by September 26 and a 90% chance by October 23.
Can it frost in Rapid City 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 May 15.
What growing zone is Rapid City?
Rapid City 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 57701. See growing zones in South Dakota.
More: all South Dakota frost dates · South Dakota growing zones · UV index today in Rapid City · frost vs. freeze