Frost dates for ZIP 99022 (Medical Lake, 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, Spokane WFO, WA (7 miles away).
- Average last spring frostMay 1050% chance of a 32°F freeze after this date
- Average first fall frostSep 2650% chance of a 32°F freeze by this date
- Growing season (frost-free)137 daysmedian, 32°F threshold
- USDA hardiness zone6b-5 to 0°F avg. coldest night
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This week in your yard
As of Oct 17, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
46°F Below 50°F
24-hour average · latest 50°F, as of Oct 17, 9:00 PM CDT
Measured at NOAA USCRN station Spokane 17 SSW, 15 mi away. Daily averages: Wed 46°, Thu 45°, Fri 45°.
4-inch depth
47°F Below 50°F
24-hour average · latest 49°F, as of Oct 17, 9:00 PM CDT
Measured at NOAA USCRN station Spokane 17 SSW, 15 mi away. Daily averages: Wed 48°, Thu 47°, Fri 47°.
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 99022 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 47°F at 4 inches. Fall pre-emergent window is mostly past. Next: spring, when soil reaches 50°F (typically 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 25 |
| 50% (the "average" last frost) | May 10 |
| 10% (cautious: only 1 year in 10 freezes later) | May 30 |
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 11 |
| 50% (the "average" first frost) | Sep 26 |
| 90% (late: most years have frozen by now) | Oct 8 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 31 | Sep 12 |
| 32°F (freeze) | May 10 | Sep 26 |
| 28°F (hard freeze) | Apr 25 | Oct 7 |
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 99022
Dates count from your average last spring frost (May 10) and first fall frost (Sep 26). 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 15–29 | May 17–31 (transplant) | – |
| Pepper (sweet and hot) | Mar 1–15 | May 24–Jun 7 (transplant) | – |
| Eggplant | Mar 1–15 | May 24–Jun 7 (transplant) | – |
| Tomatillo | Mar 15–29 | May 17–31 (transplant) | – |
| Lettuce | Mar 15–29 | Apr 19–May 10 (transplant) Apr 12–May 24 (sow outdoors) | Aug 1–22 (transplant) Jul 18–Aug 15 (sowing) |
| Spinach | – | Mar 29–Apr 19 (sow outdoors) | Aug 1–22 (sowing) |
| Kale | Mar 15–29 | Apr 12–26 (transplant) Apr 12–26 (sow outdoors) | Jul 4–Aug 1 (transplant) Jun 20–Jul 18 (sowing) |
| Collards | Mar 15–29 | Apr 12–May 10 (transplant) Apr 12–May 10 (sow outdoors) | Jul 4–Aug 1 (transplant) Jun 20–Jul 18 (sowing) |
| Broccoli | Mar 1–15 | Apr 12–26 (transplant) | Jun 20–Jul 18 (transplant) |
| Cabbage | Mar 1–15 | Apr 12–26 (transplant) | Jun 20–Jul 18 (transplant) |
| Cauliflower | Mar 1–15 | Apr 26–May 10 (transplant) | Jun 20–Jul 18 (transplant) |
| Brussels sprouts | Feb 15–Mar 1 | Apr 12–26 (transplant) | Jun 6–27 (transplant) |
| Kohlrabi | Mar 15–29 | Apr 12–26 (transplant) Apr 12–26 (sow outdoors) | Jul 18–Aug 1 (sowing) |
| Bok choy / Asian greens | – | Apr 12–26 (sow outdoors) | Aug 1–15 (sowing) |
| Arugula | – | Apr 12–May 10 (sow outdoors) | Aug 1–29 (sowing) |
| Mustard greens | – | Apr 12–May 3 (sow outdoors) | Aug 1–15 (sowing) |
| Swiss chard | Mar 29–Apr 12 | Apr 26–May 17 (transplant) Apr 26–May 24 (sow outdoors) | Jul 18–Aug 1 (sowing) |
| Beet | – | Apr 12–May 10 (sow outdoors) | Jul 18–Aug 1 (sowing) |
| Carrot | – | Apr 19–May 17 (sow outdoors) | Jul 4–18 (sowing) |
| Radish | – | Apr 5–May 17 (sow outdoors) | Aug 15–29 (sowing) |
| Turnip | – | Apr 12–May 3 (sow outdoors) | Jul 18–Aug 1 (sowing) |
| Parsnip | – | Apr 19–May 10 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 15–Apr 12 (sow outdoors) | Jul 4–18 (sowing) |
| Onion (bulbing) | Feb 15–Mar 1 | Mar 29–Apr 12 (transplant) | – |
| Green onion / scallion | – | Mar 29–Apr 26 (sow outdoors) | Jul 18–Aug 1 (sowing) |
| Leek | Feb 15–Mar 1 | Apr 12–26 (transplant) | – |
| Garlic | – | – | Aug 15–Sep 12 (sowing) |
| Shallot | – | Mar 29–Apr 12 (transplant) | Aug 15–Sep 12 (sowing) |
| Potato | – | Apr 12–26 (transplant) | Jun 6–20 (transplant) |
| Sweet potato | – | May 31–Jun 14 (transplant) | – |
| Sweet corn | – | May 17–31 (sow outdoors) | – |
| Bean, bush (snap) | – | May 17–31 (sow outdoors) | – |
| Bean, pole | – | May 17–31 (sow outdoors) | – |
| Lima bean | – | May 24–Jun 7 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 31–Jun 21 (sow outdoors) | – |
| Cucumber | Apr 12–19 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Summer squash / zucchini | Apr 12–19 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Winter squash | Apr 12–19 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Pumpkin | – | May 17–31 (sow outdoors) | – |
| Watermelon | Apr 12–19 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 12–19 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Okra | Mar 29–Apr 12 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Celery | Feb 15–Mar 1 | May 17–24 (transplant) | – |
| Basil | Mar 29–Apr 12 | May 17–31 (transplant) May 17–31 (sow outdoors) | – |
| Cilantro | – | Apr 26–May 24 (sow outdoors) | Aug 1–15 (sowing) |
| Parsley | Mar 1–15 | Apr 26–May 10 (transplant) Apr 19–May 10 (sow outdoors) | – |
| Dill | – | May 10–24 (sow outdoors) | Aug 1–15 (sowing) |
| Sunflower | – | May 10–24 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 12–26 (transplant) | – |
| Rhubarb (crowns) | – | Apr 12–26 (transplant) | – |
| Strawberry (plants) | – | Apr 12–26 (transplant) | Jul 18–Aug 15 (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: Spokane WFO, WA (NOAA GHCN-Daily ID USC00457941), elevation 2,392 ft, 6.8 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Spokane Intl AP, WA | 9 mi | Apr 26 | Oct 12 |
| Spokane 17 SSW, WA | 15 mi | May 30 | Sep 4 |
| Spokane Felts Fld, WA | 19 mi | Apr 26 | Oct 15 |
The average last-frost dates of these stations span 35 days, a rough guide to local variation. See data sources & methods.
Frost questions for 99022
When is the last frost in 99022?
The average (50% chance) last spring freeze of 32°F for ZIP 99022 is May 10. For a more cautious planting date, use May 30, when only 1 year in 10 still sees a later freeze.
When is the first frost in 99022?
The average first fall freeze is September 26. In 1 year in 10 it comes by September 11.
What hardiness zone is 99022?
ZIP 99022 is in USDA zone 6b (-5 to 0°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 99022 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
99011 Fairchild AFB 99014 Four Lakes 99001 Airway Heights 99224 Spokane 99029 Reardan 99020 99008 99201 Spokane
Other ZIP codes in Spokane County
99001 99003 99004 99005 99006 99009 99011 99012 99014 99016 99018 99019 99020 99021 99023 99025 99026 99027 99030 99031 99036 99037 99039 99201 All Spokane County frost dates · Washington frost dates
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