Checking current alerts… View NWS forecast and alerts.
Will it freeze in Sunnyside in the next 7 nights?
No overnight lows at or below 32°F are forecast in Sunnyside during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 33°F. Frost possible.
NWS forecast period: Thu, Nov 5, 6:00 PM PST to Fri, Nov 6, 6:00 AM PST.
4 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 33°F Frost possible · Areas Of Fog
- Fri, Nov 6 36°F Frost possible · Chance Rain Showers then Areas Of Fog
- Sat, Nov 7 39°F Above 36°F · Areas Of Fog
- Sun, Nov 8 34°F Frost possible · Mostly Cloudy
- Mon, Nov 9 35°F Frost possible · Chance Rain Showers
- Tue, Nov 10 38°F Above 36°F · Chance Rain Showers
- Wed, Nov 11 38°F Above 36°F · Mostly 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 Sunnyside
The median first fall hard-freeze date (28°F) is October 19, from NOAA’s 1991–2020 Climate Normals at Sunnyside. 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 1 · May 16 · Jun 7 | Sep 10 · Sep 25 · Oct 7 | 127 days |
| 32°F freeze | Apr 16 · May 1 · May 18 | Sep 25 · Oct 6 · Oct 22 | 157 days |
| 28°F hard freeze | Mar 28 · Apr 15 · May 1 | Oct 5 · Oct 19 · Nov 4 | 187 days |
Average high temperature by month
1991–2020 normals at Sunnyside
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 Sunnyside, WA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Sunnyside (station USC00458207, elevation 747 ft), 0.6 mi from Sunnyside. 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 Sunnyside
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Grandview, WA | 6.8 mi | May 1 | Oct 6 |
| Prosser, WA | 14 mi | Apr 14 | Oct 22 |
| Toppenish, WA | 16 mi | Apr 21 | Oct 15 |
| Union Gap, WA | 29 mi | May 8 | Oct 4 |
| West Richland, WA | 29 mi | Apr 6 | Oct 24 |
| Yakima, WA | 32 mi | Apr 8 | Oct 23 |
| Richland, WA | 34 mi | Apr 6 | Oct 24 |
| Selah, WA | 34 mi | May 5 | Oct 4 |
| Kennewick, WA | 40 mi | Mar 28 | Oct 30 |
| Pasco, WA | 42 mi | Apr 27 | Oct 11 |
Frequently asked questions
When is the last frost in Sunnyside?
On average, the last spring frost (32°F) in Sunnyside is around May 1. In about 1 year in 10 it comes after May 18, and in 9 years in 10 it comes after April 16.
When is the first frost in Sunnyside?
The first fall frost (32°F) usually arrives around October 6. There’s a 10% chance of a freeze by September 25 and a 90% chance by October 22.
Can it frost in Sunnyside 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 16.
What growing zone is Sunnyside?
Sunnyside is in USDA Plant Hardiness Zone 7b (average annual extreme minimum temperature 5 to 10°F), based on the 2023 USDA map for ZIP code 98930. See growing zones in Washington.
More: all Washington frost dates · Washington growing zones · frost vs. freeze