Frost Dates for 98001 — Auburn, Washington

Half of springs at Tacoma #1, WA see their last 32°F night by March 8; only one in ten is past it by February 15, and one in ten still has one after March 31. Planting tender crops after March 17 leaves a 30% risk of a frost on them, after March 23 20%, and after March 31 10%. The 23 days between the even-odds date and the one-in-ten date is wider than at 81% 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 14 in half of years, as early as October 30 one year in ten, and holds off past December 2 one year in ten. A hard freeze of 28°F follows 17 days later, around December 1; in spring the one-in-ten date for 28°F is March 4, 27 days before the 32°F one. The freeze-free season lasts 250 days in a typical year, longer than at 92% of the 113 Washington stations; it reaches 283 days one year in ten and falls short of 223 one year in ten. On average 27 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 2, and return around October 31. Nights of 24°F, cold enough to damage hardier plants, come in 72% of winters and 16°F in 4%.

July is the warmest month at Tacoma #1, WA, averaging 77°F by day and 57°F at night; December is the coldest at 47°F and 37°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From April to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 62% of years.

Warmth for growing adds up to 2,306 growing degree days a year (base 50°F), more than at 63% of the 113 Washington stations. 32% of them (733) have built up by the end of June, and July adds the most, 527. Precipitation totals 40.8 inches a year, most in November (6.5") and least in July (0.6"); May to September bring 16% of it.

The nearest other station, Kent, WA, 8 miles north of Auburn, has a last frost 12 days later (March 20), a first frost 4 days earlier (November 10), a season 17 days shorter.

Measurable snow is rare here: only 3 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Tacoma #1, WA, 7.9 miles away, so there is no typical first-snow date to plan around.

ZIP 98001 is 8 miles from Tacoma #1, WA, which stands at 25 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 17 other ZIP codes share the station; its figures are presented in full for 98003 (Federal Way). The 2023 USDA Plant Hardiness Zone Map lists ZIP 98001 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.