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Will it freeze in Harrisburg in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 31°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).
Tonight: forecast low 33°F. Frost possible.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
3 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 33°F Frost possible · Cloudy
- Fri, Nov 6 31°F Freeze · Mostly Cloudy
- Sat, Nov 7 35°F Frost possible · Mostly Clear
- Sun, Nov 8 39°F Above 36°F · Clear
- Mon, Nov 9 37°F Above 36°F · Mostly Clear
- Tue, Nov 10 37°F Above 36°F · Partly Cloudy
- Wed, Nov 11 38°F Above 36°F · 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 Harrisburg
The median first fall hard-freeze date (28°F) is October 11, from NOAA’s 1991–2020 Climate Normals at Canton. 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 | Apr 30 · May 12 · May 25 | Sep 12 · Sep 25 · Oct 7 | 135 days |
| 32°F freeze | Apr 19 · May 2 · May 15 | Sep 19 · Oct 2 · Oct 16 | 151 days |
| 28°F hard freeze | Apr 9 · Apr 23 · May 6 | Sep 27 · Oct 11 · Oct 25 | 171 days |
Average high temperature by month
1991–2020 normals at Canton
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 Harrisburg, SD come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Canton (station USC00391392, elevation 1,316 ft), 11 mi from Harrisburg. 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 Harrisburg
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Tea, SD | 5.6 mi | Apr 26 | Oct 13 |
| Sioux Falls, SD | 7.5 mi | Apr 26 | Oct 13 |
| Brandon, SD | 12 mi | May 1 | Oct 6 |
| Sioux Center, IA | 37 mi | Apr 30 | Oct 3 |
| Madison, SD | 44 mi | May 5 | Sep 30 |
| Orange City, IA | 45 mi | Apr 30 | Oct 3 |
| Vermillion, SD | 47 mi | May 3 | Oct 3 |
| Sheldon, IA | 47 mi | May 5 | Sep 28 |
| Yankton, SD | 51 mi | Apr 27 | Oct 11 |
| Le Mars, IA | 53 mi | Apr 30 | Oct 4 |
Frequently asked questions
When is the last frost in Harrisburg?
On average, the last spring frost (32°F) in Harrisburg is around May 2. In about 1 year in 10 it comes after May 15, and in 9 years in 10 it comes after April 19.
When is the first frost in Harrisburg?
The first fall frost (32°F) usually arrives around October 2. There’s a 10% chance of a freeze by September 19 and a 90% chance by October 16.
Can it frost in Harrisburg 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 12.
What growing zone is Harrisburg?
Harrisburg is in USDA Plant Hardiness Zone 5a (average annual extreme minimum temperature −20 to −15°F), based on the 2023 USDA map for ZIP code 57032. See growing zones in South Dakota.
More: all South Dakota frost dates · South Dakota growing zones · frost vs. freeze