USDA Hardiness Zone 8b
Frost Dates for 98520 — Aberdeen, Washington
NOAA 1991–2020 normals from Aberdeen, WA (10 ft), under a mile southwest.
Updated
In Aberdeen, the last spring frost (32°F) is around March 29 in half of years and has passed by April 20 in nine years out of ten. The first fall frost comes around November 15, as early as October 27 one year in ten, leaving a typical freeze-free season of 234 days (NOAA, Aberdeen, WA).
- Last spring frost
- March 29
- First fall frost
- November 15
- Growing season
- 234 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
- Rare
- Last snow
- Rare
- Winters with snow
- 15%
- Snow per year
- 0.5"
median, 1991–2020
median, 1991–2020
3 of 20 observed
NOAA normal
Frost risk by date in Aberdeen
Half of springs at Aberdeen, WA see their last 32°F night by March 29; only one in ten is past it by February 25, and one in ten still has one after April 20. Planting tender crops after April 5 leaves a 30% risk of a frost on them, after April 12 20%, and after April 20 10%. The 22 days between the even-odds date and the one-in-ten date is wider than at 71% of the 113 Washington stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.
In fall the first 32°F night comes by November 15 in half of years, as early as October 27 one year in ten, and holds off past December 10 one year in ten. A hard freeze of 28°F follows 21 days later, around December 6; in spring the one-in-ten date for 28°F is March 20, 31 days before the 32°F one. The freeze-free season lasts 234 days in a typical year, longer than at 84% of the 113 Washington stations; it reaches 272 days one year in ten and falls short of 204 one year in ten. On average 35 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 25 days longer, to about April 23, and return around October 27. Nights of 24°F, cold enough to damage hardier plants, come in 54% of winters and 16°F in 1%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 4 | Apr 10 | Apr 15 | Apr 19 | Apr 23 | Apr 27 | Apr 30 | May 5 | May 11 |
| 32°F | Feb 25 | Mar 6 | Mar 15 | Mar 23 | Mar 29 | Apr 1 | Apr 5 | Apr 12 | Apr 20 |
| 28°F95% of yrs | Dec 27 | Jan 16 | Jan 31 | Feb 10 | Feb 18 | Feb 24 | Feb 28 | Mar 7 | Mar 20 |
| 24°F54% of yrs | Dec 2 | Dec 11 | Dec 20 | Dec 29 | Jan 5 | Jan 14 | Jan 29 | Feb 10 | Feb 20 |
| 20°F12% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 11 | Oct 17 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 2 | Nov 7 | Nov 14 |
| 32°F | Oct 27 | Nov 1 | Nov 6 | Nov 11 | Nov 15 | Nov 21 | Nov 26 | Dec 1 | Dec 10 |
| 28°F95% of yrs | Nov 11 | Nov 21 | Nov 27 | Dec 1 | Dec 6 | Dec 13 | Dec 23 | Jan 2 | Jan 26 |
| 24°F54% of yrs | Nov 26 | Dec 1 | Dec 7 | Dec 13 | Dec 19 | Dec 27 | Jan 4 | Jan 16 | Feb 8 |
| 20°F12% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Aberdeen, 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 98520 →Compare Aberdeen with another place →
Weather by month in Aberdeen
August is the warmest month at Aberdeen, WA, averaging 69°F by day and 54°F at night; December is the coldest at 47°F and 37°F. A freezing night is all but certain in December (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 88% of years and March still brings one in 76% of years and April still brings one in 41% of years.
Warmth for growing adds up to 1,591 growing degree days a year (base 50°F), fewer than at 84% of the 113 Washington stations. 28% of them (444) have built up by the end of June, and August adds the most, 367. Precipitation totals 85.0 inches a year, most in January (13.9") and least in July (0.9"); May to September bring 13% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 48 | 37 | 13.9 | 88% | 8 | 3 |
| Feb | 50 | 37 | 8.6 | 88% | 8 | 5 |
| Mar | 53 | 38 | 9.8 | 76% | 5 | 17 |
| Apr | 57 | 41 | 6.3 | 41% | 1 | 40 |
| May | 61 | 47 | 3.5 | 2% | 0 | 140 |
| Jun | 65 | 51 | 2.4 | 0% | 0 | 239 |
| Jul | 68 | 54 | 0.9 | 0% | 0 | 347 |
| Aug | 69 | 54 | 1.5 | 0% | 0 | 367 |
| Sep | 69 | 51 | 2.7 | 0% | 0 | 297 |
| Oct | 61 | 45 | 8.3 | 19% | 1 | 116 |
| Nov | 52 | 40 | 13.7 | 74% | 4 | 17 |
| Dec | 47 | 37 | 13.4 | 96% | 8 | 3 |
Monthly normals 1991–2020 at Aberdeen, WA (10 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Hoquiam Bowerman Airport, WA, 5 miles west of Aberdeen, has a last frost 1 day later (March 30), a first frost 1 day earlier (November 14), a season 6 days shorter.
When it snows in Aberdeen, Washington
Measurable snow is rare here: only 3 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Aberdeen, WA, 0.7 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 98520
| When | What to do |
|---|---|
| January 18 – February 1 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 1 – February 15 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 1 – March 15 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 29 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 23 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 1 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 15 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 98520 is under a mile from Aberdeen, WA, which stands at 10 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 98520 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.