Frost dates 2026–2027

Frost dates for Moscow, Idaho

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Pullman Moscow Regional Airport, 5.3 mi away (close match).

Last spring frostApr 29
First fall frostOct 2
159 frost-free days
Last spring frostApr 291 year in 10 after May 14
First fall frostOct 21 year in 10 by Sep 17
Growing season159 daysbetween median 32°F dates
Hardiness zoneZone 6b−5 to 0°F average extreme low

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Will it freeze in Moscow in the next 7 nights?

No overnight lows at or below 32°F are forecast in Moscow during the next 7 nights in the available NWS frost forecast.

Tonight: forecast low 34°F. Frost possible.

NWS forecast period: Thu, Nov 5, 6:00 PM PST to Fri, Nov 6, 6:00 AM PST.

2 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.

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 Moscow

The median first fall hard-freeze date (28°F) is October 18, from NOAA’s 1991–2020 Climate Normals at Pullman Moscow Regional Airport. This is the 50% probability date, not a forecast for this year.

TemperatureLast 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 2 · May 18 · Jun 14 Aug 28 · Sep 19 · Oct 5 120 days
32°F freeze Apr 7 · Apr 29 · May 14 Sep 17 · Oct 2 · Oct 25 159 days
28°F hard freeze Mar 9 · Apr 3 · Apr 27 Sep 29 · Oct 18 · Nov 15 197 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094129. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Pullman Moscow Regional Airport

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 Moscow, ID come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Pullman Moscow Regional Airport (station USW00094129, elevation 2,551 ft), 5.3 mi from Moscow. 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 Moscow

CityDistanceLast spring frostFirst fall frost
Pullman, WA 8.1 mi May 6 Sep 29
Clarkston, WA 22 mi Apr 6 Oct 26
Lewiston, ID 24 mi Apr 6 Oct 26
Cheney, WA 59 mi May 30 Sep 4
Liberty Lake, WA 65 mi Apr 26 Oct 15
Spokane Valley, WA 65 mi Apr 26 Oct 15
Spokane, WA 68 mi Apr 26 Oct 15
Coeur d'Alene, ID 68 mi Apr 22 Oct 18
Post Falls, ID 69 mi Apr 22 Oct 18
Airway Heights, WA 69 mi Apr 26 Oct 12

Frequently asked questions

When is the last frost in Moscow?

On average, the last spring frost (32°F) in Moscow is around April 29. In about 1 year in 10 it comes after May 14, and in 9 years in 10 it comes after April 7.

When is the first frost in Moscow?

The first fall frost (32°F) usually arrives around October 2. There’s a 10% chance of a freeze by September 17 and a 90% chance by October 25.

Can it frost in Moscow 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 18.

What growing zone is Moscow?

Moscow is in USDA Plant Hardiness Zone 6b (average annual extreme minimum temperature −5 to 0°F), based on the 2023 USDA map for ZIP code 83844. See growing zones in Idaho.

More: all Idaho frost dates · Idaho growing zones · UV index today in Moscow · frost vs. freeze