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Will it freeze in Green River in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 29°F (Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST).
Tonight: forecast low 29°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 29°F Freeze · Mostly Cloudy
- Fri, Nov 6 26°F Hard freeze · Mostly Clear
- Sat, Nov 7 30°F Freeze · Mostly Clear
- Sun, Nov 8 33°F Frost possible · Mostly Clear
- Mon, Nov 9 34°F Frost possible · Partly Cloudy
- Tue, Nov 10 33°F Frost possible · Partly Cloudy
- Wed, Nov 11 34°F Frost possible · 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 Green River
The median first fall hard-freeze date (28°F) is October 3, from NOAA’s 1991–2020 Climate Normals at Green Rvr. 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 22 · Jun 7 · Jun 21 | Sep 1 · Sep 13 · Sep 25 | 96 days |
| 32°F freeze | May 7 · May 24 · Jun 10 | Sep 7 · Sep 22 · Oct 6 | 120 days |
| 28°F hard freeze | Apr 25 · May 9 · May 28 | Sep 18 · Oct 3 · Oct 18 | 146 days |
Average high temperature by month
1991–2020 normals at Green Rvr
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 Green River, WY come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Green Rvr (station USC00484065, elevation 6,160 ft), 0.2 mi from Green River. 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 Green River
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Rock Springs, WY | 14 mi | May 24 | Sep 24 |
| Vernal, UT | 73 mi | May 7 | Oct 6 |
| Evanston, WY | 80 mi | Jun 12 | Sep 12 |
| Roosevelt, UT | 89 mi | May 23 | Sep 22 |
| Lander, WY | 99 mi | May 18 | Sep 27 |
| Rawlins, WY | 117 mi | May 17 | Oct 2 |
| Riverton, WY | 119 mi | May 12 | Sep 24 |
| Heber, UT | 121 mi | Jun 4 | Sep 20 |
| Park City, UT | 121 mi | May 29 | Sep 25 |
| Craig, CO | 121 mi | Jun 6 | Sep 12 |
Frequently asked questions
When is the last frost in Green River?
On average, the last spring frost (32°F) in Green River is around May 24. In about 1 year in 10 it comes after June 10, and in 9 years in 10 it comes after May 7.
When is the first frost in Green River?
The first fall frost (32°F) usually arrives around September 22. There’s a 10% chance of a freeze by September 7 and a 90% chance by October 6.
Can it frost in Green River 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 June 7.
What growing zone is Green River?
Green River 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 82935. See growing zones in Wyoming.
More: all Wyoming frost dates · Wyoming growing zones · frost vs. freeze