USDA Hardiness Zone 8b
Frost Dates for 98092 — Auburn, Washington
NOAA 1991–2020 normals from Kent, WA (30 ft), 9 miles northwest.
Updated
In Auburn, the last spring frost (32°F) is around March 20 in half of years and has passed by April 8 in nine years out of ten. The first fall frost comes around November 10, as early as October 26 one year in ten, leaving a typical freeze-free season of 233 days (NOAA, Kent, WA).
- Last spring frost
- March 20
- First fall frost
- November 10
- Growing season
- 233 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
- 30%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
6 of 20 observed
NOAA normal
Frost risk by date in Auburn
Half of springs at Kent, WA see their last 32°F night by March 20; only one in ten is past it by February 27, and one in ten still has one after April 8. Planting tender crops after March 29 leaves a 30% risk of a frost on them, after April 1 20%, and after April 8 10%. The 19 days between the even-odds date and the one-in-ten date is narrower than at 49% of the 113 Washington stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 10 in half of years, as early as October 26 one year in ten, and holds off past November 26 one year in ten. A hard freeze of 28°F follows 14 days later, around November 24; in spring the one-in-ten date for 28°F is March 16, 23 days before the 32°F one. The freeze-free season lasts 233 days in a typical year, longer than at 83% of the 113 Washington stations; it reaches 262 days one year in ten and falls short of 207 one year in ten. On average 39 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 22 days longer, to about April 11, and return around October 27. Nights of 24°F, cold enough to damage hardier plants, come in 88% of winters and 16°F in 11%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 26 | Mar 31 | Apr 4 | Apr 7 | Apr 11 | Apr 15 | Apr 19 | Apr 24 | Apr 30 |
| 32°F | Feb 27 | Mar 6 | Mar 12 | Mar 16 | Mar 20 | Mar 24 | Mar 29 | Apr 1 | Apr 8 |
| 28°F | Jan 19 | Feb 6 | Feb 15 | Feb 20 | Feb 25 | Feb 28 | Mar 5 | Mar 11 | Mar 16 |
| 24°F88% of yrs | Dec 8 | Dec 20 | Jan 2 | Jan 10 | Jan 24 | Feb 1 | Feb 12 | Feb 19 | Feb 27 |
| 20°F46% of yrs | too rare for a date | ||||||||
| 16°F11% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 13 | Oct 17 | Oct 20 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 5 | Nov 11 |
| 32°F | Oct 26 | Oct 31 | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 | Nov 26 |
| 28°F | Nov 6 | Nov 11 | Nov 15 | Nov 20 | Nov 24 | Nov 27 | Dec 2 | Dec 8 | Dec 20 |
| 24°F88% of yrs | Nov 16 | Nov 24 | Nov 29 | Dec 4 | Dec 8 | Dec 16 | Dec 24 | Jan 2 | Jan 17 |
| 20°F46% of yrs | too rare for a date | ||||||||
| 16°F11% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Kent, 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 98092 →Compare Auburn with another place →
Weather by month in Auburn
July is the warmest month at Kent, WA, averaging 78°F by day and 57°F at night; December is the coldest at 47°F and 35°F. A freezing night is all but certain in every month from November to February (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 84% of years and April still brings one in 22% of years.
Warmth for growing adds up to 2,408 growing degree days a year (base 50°F), more than at 71% of the 113 Washington stations. 32% of them (773) have built up by the end of June, and July adds the most, 552. Precipitation totals 40.3 inches a year, most in November (6.2") and least in July (0.7"); May to September bring 17% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 48 | 36 | 5.8 | 99% | 9 | 5 |
| Feb | 51 | 36 | 4.0 | 96% | 8 | 6 |
| Mar | 56 | 39 | 4.4 | 84% | 4 | 30 |
| Apr | 61 | 43 | 3.1 | 22% | 1 | 94 |
| May | 68 | 49 | 2.1 | 0% | 0 | 261 |
| Jun | 72 | 53 | 1.7 | 0% | 0 | 378 |
| Jul | 78 | 57 | 0.7 | 0% | 0 | 552 |
| Aug | 78 | 57 | 0.9 | 0% | 0 | 552 |
| Sep | 73 | 52 | 1.5 | 0% | 0 | 374 |
| Oct | 61 | 46 | 4.1 | 23% | 1 | 133 |
| Nov | 53 | 39 | 6.2 | 92% | 6 | 22 |
| Dec | 47 | 35 | 5.8 | 100% | 11 | 3 |
Monthly normals 1991–2020 at Kent, WA (30 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, Landsburg, WA, 11 miles northeast of Auburn and 505 feet higher, has a last frost 31 days later (April 20), a first frost 16 days earlier (October 25), a season 46 days shorter.
When it snows in Auburn, Washington
Measurable snow is rare here: only 6 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Kent, WA, 9.1 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 98092
| When | What to do |
|---|---|
| January 9 – January 23 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 23 – February 6 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 20 – March 6 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 20 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 10 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 98092 is 9 miles from Kent, WA, which stands at 30 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 98092 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.