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Will it freeze in Windsor in the next 7 nights?
No overnight lows at or below 32°F are forecast in Windsor during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 35°F. Frost possible.
NWS forecast period: Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST.
5 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 34°F Frost possible · Mostly Clear
- Sat, Nov 7 34°F Frost possible · Mostly Clear
- Sun, Nov 8 37°F Above 36°F · Clear
- Mon, Nov 9 37°F Above 36°F · Mostly Clear
- Tue, Nov 10 36°F Frost possible · Partly Cloudy
- Wed, Nov 11 36°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 Windsor
The median first fall hard-freeze date (28°F) is October 14, from NOAA’s 1991–2020 Climate Normals at Ft Collins 4 E. 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 3 · May 14 · May 26 | Sep 13 · Sep 27 · Oct 8 | 136 days |
| 32°F freeze | Apr 21 · May 3 · May 15 | Sep 22 · Oct 6 · Oct 17 | 154 days |
| 28°F hard freeze | Apr 8 · Apr 23 · May 8 | Sep 30 · Oct 14 · Oct 26 | 174 days |
Average high temperature by month
1991–2020 normals at Ft Collins 4 E
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 Windsor, CO come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Ft Collins 4 E (station USC00053006, elevation 4,920 ft), 8.8 mi from Windsor. 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 Windsor
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Severance, CO | 3.1 mi | May 3 | Oct 6 |
| Timnath, CO | 5.0 mi | May 3 | Oct 6 |
| Greeley, CO | 8.7 mi | May 2 | Oct 8 |
| Loveland, CO | 8.7 mi | May 10 | Oct 1 |
| Fort Collins, CO | 9.3 mi | May 2 | Oct 7 |
| Eaton, CO | 11 mi | May 2 | Oct 8 |
| Johnstown, CO | 12 mi | May 10 | Oct 1 |
| Milliken, CO | 12 mi | May 2 | Oct 8 |
| Evans, CO | 12 mi | May 2 | Oct 8 |
| Berthoud, CO | 14 mi | May 7 | Oct 5 |
Frequently asked questions
When is the last frost in Windsor?
On average, the last spring frost (32°F) in Windsor is around May 3. In about 1 year in 10 it comes after May 15, and in 9 years in 10 it comes after April 21.
When is the first frost in Windsor?
The first fall frost (32°F) usually arrives around October 6. There’s a 10% chance of a freeze by September 22 and a 90% chance by October 17.
Can it frost in Windsor 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 14.
What growing zone is Windsor?
Windsor 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 80550. See growing zones in Colorado.
More: all Colorado frost dates · Colorado growing zones · UV index today in Windsor · frost vs. freeze