USDA Hardiness Zone 8b
Frost Dates for 98223 — Arlington, Washington
NOAA 1991–2020 normals from Arlington, WA (100 ft), 4 miles west.
Updated
In Arlington, the last spring frost (32°F) is around April 22 in half of years and has passed by May 6 in nine years out of ten. The first fall frost comes around October 19, as early as October 3 one year in ten, leaving a typical freeze-free season of 181 days (NOAA, Arlington, WA).
- Last spring frost
- April 22
- First fall frost
- October 19
- Growing season
- 181 days
- Hardiness zone
- 8b
50% probability
50% probability
freeze-free, 50%
15 to 20°F (-9.4 to -6.7°C) coldest night
- First snow
- December 25
- Last snow
- February 18
- Winters with snow
- 71%
- Snow per year
- 4.3"
median, 1991–2020
median, 1991–2020
12 of 17 observed
NOAA normal
Frost risk by date in Arlington
Half of springs at Arlington, WA see their last 32°F night by April 22; only one in ten is past it by April 4, and one in ten still has one after May 6. Planting tender crops after April 28 leaves a 30% risk of a frost on them, after May 2 20%, and after May 6 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 88% of the 113 Washington stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 19 in half of years, as early as October 3 one year in ten, and holds off past November 4 one year in ten. A hard freeze of 28°F follows 15 days later, around November 3; in spring the one-in-ten date for 28°F is April 15, 21 days before the 32°F one. The freeze-free season lasts 181 days in a typical year, shorter than at 58% of the 113 Washington stations; it reaches 205 days one year in ten and falls short of 159 one year in ten. On average 94 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 18 days longer, to about May 10, and return around October 2. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 61%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 28 | May 2 | May 4 | May 7 | May 10 | May 13 | May 16 | May 19 | May 24 |
| 32°F | Apr 4 | Apr 9 | Apr 13 | Apr 18 | Apr 22 | Apr 25 | Apr 28 | May 2 | May 6 |
| 28°F | Mar 3 | Mar 11 | Mar 15 | Mar 21 | Mar 25 | Mar 30 | Apr 2 | Apr 6 | Apr 15 |
| 24°F | Jan 19 | Feb 7 | Feb 16 | Feb 21 | Feb 26 | Mar 1 | Mar 5 | Mar 11 | Mar 17 |
| 20°F93% of yrs | Dec 13 | Dec 30 | Jan 7 | Jan 19 | Jan 31 | Feb 7 | Feb 15 | Feb 23 | Feb 28 |
| 16°F61% of yrs | Dec 2 | Dec 10 | Dec 18 | Dec 27 | Jan 2 | Jan 14 | Jan 27 | Feb 6 | Feb 17 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 17 | Sep 22 | Sep 26 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 12 | Oct 17 |
| 32°F | Oct 3 | Oct 8 | Oct 12 | Oct 16 | Oct 19 | Oct 23 | Oct 25 | Oct 29 | Nov 4 |
| 28°F | Oct 19 | Oct 25 | Oct 29 | Oct 31 | Nov 3 | Nov 8 | Nov 12 | Nov 17 | Nov 23 |
| 24°F | Oct 31 | Nov 7 | Nov 11 | Nov 16 | Nov 21 | Nov 25 | Nov 30 | Dec 5 | Dec 16 |
| 20°F93% of yrs | Nov 14 | Nov 22 | Nov 27 | Dec 1 | Dec 6 | Dec 13 | Dec 21 | Jan 1 | Jan 18 |
| 16°F61% of yrs | Nov 23 | Nov 30 | Dec 4 | Dec 8 | Dec 16 | Dec 23 | Dec 31 | Jan 11 | Jan 29 |
Freeze probabilities 1991–2020 at Arlington, WA, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 98223 →Compare Arlington with another place →
Compared with the next station
The nearest other station, Everett, WA, 17 miles southwest of Arlington, has a last frost 29 days earlier (March 24), a first frost 14 days later (November 2), a season 42 days longer.
When it snows in Arlington, Washington
The first measurable snow (0.1 inch or more) in Arlington usually arrives around December 25, and the last of the season around February 18. Those are the middle dates across the winters of 1991–2020 at Arlington, WA, 3.5 miles away: half of years saw snow earlier, half later. Snow fell in 71% of those winters. The last 32°F night of spring typically comes 63 days after the last snow.
Planting calendar for 98223
| When | What to do |
|---|---|
| February 11 – February 25 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 25 – March 11 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 25 – April 8 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 22 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 27 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 5 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 19 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 98223 is 4 miles from Arlington, WA, which stands at 100 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 98223 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Washington →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.