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Will it freeze in Cortez in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 32°F (Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST).
Tonight: forecast low 32°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 32°F Freeze · Mostly Cloudy
- Fri, Nov 6 29°F Freeze · Mostly Clear
- Sat, Nov 7 30°F Freeze · Clear
- Sun, Nov 8 31°F Freeze · Mostly Clear
- Mon, Nov 9 32°F Freeze · Mostly Clear
- Tue, Nov 10 32°F Freeze · Partly Cloudy
- Wed, Nov 11 32°F Freeze · 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 Cortez
The median first fall hard-freeze date (28°F) is October 17, from NOAA’s 1991–2020 Climate Normals at Cortez. 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 13 · May 26 · Jun 12 | Sep 18 · Sep 30 · Oct 12 | 125 days |
| 32°F freeze | Apr 30 · May 12 · May 31 | Sep 26 · Oct 7 · Oct 21 | 147 days |
| 28°F hard freeze | Apr 14 · Apr 30 · May 14 | Oct 4 · Oct 17 · Nov 1 | 171 days |
Average high temperature by month
1991–2020 normals at Cortez
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 Cortez, CO come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Cortez (station USC00051886, elevation 6,167 ft), 1.1 mi from Cortez. 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 Cortez
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Durango, CO | 39 mi | May 21 | Oct 2 |
| Farmington, NM | 47 mi | May 2 | Oct 13 |
| Aztec, NM | 50 mi | May 12 | Oct 6 |
| Bloomfield, NM | 53 mi | Apr 23 | Oct 19 |
| Montrose, CO | 86 mi | Apr 28 | Oct 14 |
| Moab, UT | 99 mi | Apr 11 | Oct 23 |
| Delta, CO | 101 mi | May 1 | Oct 7 |
| Grand Junction, CO | 120 mi | Apr 14 | Oct 23 |
| Gunnison, CO | 122 mi | Jun 21 | Sep 5 |
| Fruita, CO | 125 mi | Apr 27 | Oct 11 |
Frequently asked questions
When is the last frost in Cortez?
On average, the last spring frost (32°F) in Cortez is around May 12. In about 1 year in 10 it comes after May 31, and in 9 years in 10 it comes after April 30.
When is the first frost in Cortez?
The first fall frost (32°F) usually arrives around October 7. There’s a 10% chance of a freeze by September 26 and a 90% chance by October 21.
Can it frost in Cortez 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 26.
What growing zone is Cortez?
Cortez is in USDA Plant Hardiness Zone 7a (average annual extreme minimum temperature 0 to 5°F), based on the 2023 USDA map for ZIP code 81321. See growing zones in Colorado.
More: all Colorado frost dates · Colorado growing zones · frost vs. freeze