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Will it freeze in Anamosa in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 27°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).
Tonight: forecast low 35°F. Frost possible.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
4 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 35°F Frost possible · Mostly Cloudy
- Fri, Nov 6 27°F Hard freeze · Mostly Clear
- Sat, Nov 7 34°F Frost possible · Mostly Clear
- Sun, Nov 8 35°F Frost possible · Clear
- Mon, Nov 9 39°F Above 36°F · Mostly Clear
- Tue, Nov 10 38°F Above 36°F · Partly Cloudy
- Wed, Nov 11 39°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 Anamosa
The median first fall hard-freeze date (28°F) is October 16, from NOAA’s 1991–2020 Climate Normals at Anamosa 1 Wnw. 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 28 · May 13 · May 28 | Sep 14 · Sep 27 · Oct 8 | 137 days |
| 32°F freeze | Apr 18 · May 1 · May 18 | Sep 21 · Oct 4 · Oct 18 | 154 days |
| 28°F hard freeze | Apr 6 · Apr 21 · May 6 | Oct 1 · Oct 16 · Oct 30 | 175 days |
Average high temperature by month
1991–2020 normals at Anamosa 1 Wnw
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 Anamosa, IA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Anamosa 1 Wnw (station USC00130213, elevation 805 ft), 0.9 mi from Anamosa. 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 Anamosa
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Marion, IA | 17 mi | Apr 28 | Oct 12 |
| Hiawatha, IA | 22 mi | Apr 28 | Oct 12 |
| Cedar Rapids, IA | 23 mi | Apr 27 | Oct 11 |
| Manchester, IA | 27 mi | May 3 | Oct 4 |
| North Liberty, IA | 30 mi | Apr 21 | Oct 18 |
| Maquoketa, IA | 32 mi | Apr 25 | Oct 14 |
| Coralville, IA | 33 mi | Apr 21 | Oct 18 |
| Iowa City, IA | 34 mi | Apr 21 | Oct 18 |
| Tiffin, IA | 34 mi | Apr 21 | Oct 18 |
| Asbury, IA | 38 mi | Apr 19 | Oct 21 |
Frequently asked questions
When is the last frost in Anamosa?
On average, the last spring frost (32°F) in Anamosa is around May 1. In about 1 year in 10 it comes after May 18, and in 9 years in 10 it comes after April 18.
When is the first frost in Anamosa?
The first fall frost (32°F) usually arrives around October 4. There’s a 10% chance of a freeze by September 21 and a 90% chance by October 18.
Can it frost in Anamosa 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 13.
What growing zone is Anamosa?
Anamosa 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 52205. See growing zones in Iowa.
More: all Iowa frost dates · Iowa growing zones · frost vs. freeze