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Will it freeze in Anaconda in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 19°F (Thu, Nov 5, 6:00 PM MST to Fri, Nov 6, 6:00 AM MST).
Tonight: forecast low 19°F. Hard 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 19°F Hard freeze · Slight Chance Light Snow then Mostly Clear
- Fri, Nov 6 28°F Hard freeze · Partly Cloudy
- Sat, Nov 7 31°F Freeze · Partly Cloudy
- Sun, Nov 8 26°F Hard freeze · Mostly Cloudy
- Mon, Nov 9 29°F Freeze · Partly Cloudy
- Tue, Nov 10 30°F Freeze · Partly Cloudy
- Wed, Nov 11 31°F Freeze · 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 Anaconda
The median first fall hard-freeze date (28°F) is September 28, from NOAA’s 1991–2020 Climate Normals at Anaconda. 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 | rare in most years | rare in most years | 71 days |
| 32°F freeze | May 14 · Jun 1 · Jun 25 | Aug 31 · Sep 14 · Oct 1 | 105 days |
| 28°F hard freeze | Apr 29 · May 13 · May 30 | Sep 12 · Sep 28 · Oct 12 | 138 days |
Average high temperature by month
1991–2020 normals at Anaconda
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 Anaconda, MT come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Anaconda (station USC00240199, elevation 5,230 ft), 10 mi from Anaconda. 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 Anaconda
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Butte, MT | 27 mi | Jun 13 | Sep 5 |
| Hamilton, MT | 50 mi | May 21 | Sep 22 |
| Helena, MT | 64 mi | May 9 | Sep 30 |
| Missoula, MT | 68 mi | May 10 | Oct 1 |
| Belgrade, MT | 97 mi | May 26 | Sep 16 |
| Bozeman, MT | 104 mi | May 26 | Sep 22 |
| Polson, MT | 120 mi | May 10 | Oct 5 |
| Livingston, MT | 128 mi | May 27 | Sep 14 |
| Great Falls, MT | 130 mi | May 6 | Oct 1 |
| Kalispell, MT | 157 mi | May 31 | Sep 10 |
Frequently asked questions
When is the last frost in Anaconda?
On average, the last spring frost (32°F) in Anaconda is around June 1. In about 1 year in 10 it comes after June 25, and in 9 years in 10 it comes after May 14.
When is the first frost in Anaconda?
The first fall frost (32°F) usually arrives around September 14. There’s a 10% chance of a freeze by August 31 and a 90% chance by October 1.
What growing zone is Anaconda?
Anaconda 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 59711. See growing zones in Montana.
More: all Montana frost dates · Montana growing zones · frost vs. freeze