Fall in zone 7bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 98938 (Outlook, WA)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Sunnyside, WA (6 miles away).
- Average last spring frostMay 150% chance of a 32°F freeze after this date
- Average first fall frostOct 650% chance of a 32°F freeze by this date
- Growing season (frost-free)157 daysmedian, 32°F threshold
- USDA hardiness zone7b5 to 10°F avg. coldest night
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Frost and freeze alerts from the NWS forecast for 98938, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
No soil station with a fresh reading within 62 miles.
4-inch depth
No soil station with a fresh reading within 62 miles.
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 98938 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
No soil reading near this ZIP. Typical extension timing for your region: spring mid-April to mid-May.
Fertilizer window
Lawn region: Mountain West and High Plains. Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Apr 16 |
| 50% (the "average" last frost) | May 1 |
| 10% (cautious: only 1 year in 10 freezes later) | May 18 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Sep 25 |
| 50% (the "average" first frost) | Oct 6 |
| 90% (late: most years have frozen by now) | Oct 22 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 16 | Sep 25 |
| 32°F (freeze) | May 1 | Oct 6 |
| 28°F (hard freeze) | Apr 15 | Oct 19 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 98938
Dates count from your average last spring frost (May 1) and first fall frost (Oct 6). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Mar 6–20 | May 8–22 (transplant) | – |
| Pepper (sweet and hot) | Feb 20–Mar 6 | May 15–29 (transplant) | – |
| Eggplant | Feb 20–Mar 6 | May 15–29 (transplant) | – |
| Tomatillo | Mar 6–20 | May 8–22 (transplant) | – |
| Lettuce | Mar 6–20 | Apr 10–May 1 (transplant) Apr 3–May 15 (sow outdoors) | Aug 11–Sep 1 (transplant) Jul 28–Aug 25 (sowing) |
| Spinach | – | Mar 20–Apr 10 (sow outdoors) | Aug 11–Sep 1 (sowing) |
| Kale | Mar 6–20 | Apr 3–17 (transplant) Apr 3–17 (sow outdoors) | Jul 14–Aug 11 (transplant) Jun 30–Jul 28 (sowing) |
| Collards | Mar 6–20 | Apr 3–May 1 (transplant) Apr 3–May 1 (sow outdoors) | Jul 14–Aug 11 (transplant) Jun 30–Jul 28 (sowing) |
| Broccoli | Feb 20–Mar 6 | Apr 3–17 (transplant) | Jun 30–Jul 28 (transplant) |
| Cabbage | Feb 20–Mar 6 | Apr 3–17 (transplant) | Jun 30–Jul 28 (transplant) |
| Cauliflower | Feb 20–Mar 6 | Apr 17–May 1 (transplant) | Jun 30–Jul 28 (transplant) |
| Brussels sprouts | Feb 6–20 | Apr 3–17 (transplant) | Jun 16–Jul 7 (transplant) |
| Kohlrabi | Mar 6–20 | Apr 3–17 (transplant) Apr 3–17 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Bok choy / Asian greens | – | Apr 3–17 (sow outdoors) | Aug 11–25 (sowing) |
| Arugula | – | Apr 3–May 1 (sow outdoors) | Aug 11–Sep 8 (sowing) |
| Mustard greens | – | Apr 3–24 (sow outdoors) | Aug 11–25 (sowing) |
| Swiss chard | Mar 20–Apr 3 | Apr 17–May 8 (transplant) Apr 17–May 15 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Beet | – | Apr 3–May 1 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Carrot | – | Apr 10–May 8 (sow outdoors) | Jul 14–28 (sowing) |
| Radish | – | Mar 27–May 8 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Turnip | – | Apr 3–24 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Parsnip | – | Apr 10–May 1 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 6–Apr 3 (sow outdoors) | Jul 14–28 (sowing) |
| Onion (bulbing) | Feb 6–20 | Mar 20–Apr 3 (transplant) | – |
| Green onion / scallion | – | Mar 20–Apr 17 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Leek | Feb 6–20 | Apr 3–17 (transplant) | – |
| Garlic | – | – | Aug 25–Sep 22 (sowing) |
| Shallot | – | Mar 20–Apr 3 (transplant) | Aug 25–Sep 22 (sowing) |
| Potato | – | Apr 3–17 (transplant) | Jun 16–30 (transplant) |
| Sweet potato | – | May 22–Jun 5 (transplant) | – |
| Sweet corn | – | May 8–22 (sow outdoors) | – |
| Bean, bush (snap) | – | May 8–22 (sow outdoors) | – |
| Bean, pole | – | May 8–22 (sow outdoors) | – |
| Lima bean | – | May 15–29 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 22–Jun 12 (sow outdoors) | – |
| Cucumber | Apr 3–10 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Summer squash / zucchini | Apr 3–10 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Winter squash | Apr 3–10 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Pumpkin | – | May 8–22 (sow outdoors) | – |
| Watermelon | Apr 3–10 | May 15–29 (transplant) May 15–29 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 3–10 | May 15–29 (transplant) May 15–29 (sow outdoors) | – |
| Okra | Mar 20–Apr 3 | May 15–29 (transplant) May 15–29 (sow outdoors) | – |
| Celery | Feb 6–20 | May 8–15 (transplant) | – |
| Basil | Mar 20–Apr 3 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Cilantro | – | Apr 17–May 15 (sow outdoors) | Aug 11–25 (sowing) |
| Parsley | Feb 20–Mar 6 | Apr 17–May 1 (transplant) Apr 10–May 1 (sow outdoors) | – |
| Dill | – | May 1–15 (sow outdoors) | Aug 11–25 (sowing) |
| Sunflower | – | May 1–15 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 3–17 (transplant) | – |
| Rhubarb (crowns) | – | Apr 3–17 (transplant) | – |
| Strawberry (plants) | – | Apr 3–17 (transplant) | Jul 28–Aug 25 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Sunnyside, WA (NOAA GHCN-Daily ID USC00458207), elevation 747 ft, 6.1 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Sunnyside #2, WA | 4 mi | Apr 30 | Oct 8 |
| Moxee City 10 E, WA | 9 mi | May 4 | Oct 10 |
| Wapato, WA | 16 mi | Apr 21 | Oct 15 |
The average last-frost dates of these stations span 14 days, a rough guide to local variation. See data sources & methods.
Frost questions for 98938
When is the last frost in 98938?
The average (50% chance) last spring freeze of 32°F for ZIP 98938 is May 1. For a more cautious planting date, use May 18, when only 1 year in 10 still sees a later freeze.
When is the first frost in 98938?
The average first fall freeze is October 6. In 1 year in 10 it comes by September 25.
What hardiness zone is 98938?
ZIP 98938 is in USDA zone 7b (5 to 10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 98938 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
98932 Granger 98953 Zillah 98936 Moxee 98921 Buena 98930 Grandview 98948 Toppenish 98935 Mabton 98939 Parker
Other ZIP codes in Yakima County
98901 98902 98903 98908 98921 98923 98930 98932 98933 98935 98936 98937 98939 98942 98947 98948 98951 98952 98953 All Yakima County frost dates · Washington frost dates
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- Freeze alerts
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Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.