USDA Hardiness Zone 8b

Frost Dates for 98230 — Blaine, Washington

NOAA 1991–2020 normals from Blaine, WA (60 ft), 3 miles northwest.

Updated October 28, 2026

In Blaine, the last spring frost (32°F) is around March 31 in half of years and has passed by April 22 in nine years out of ten. The first fall frost comes around November 4, as early as October 18 one year in ten, leaving a typical freeze-free season of 219 days (NOAA, Blaine, WA).

Last spring frost: March 31
First fall frost: November 4
Growing season: 219 days
Hardiness zone: 8b

First snow: December 23
Last snow: February 21
Winters with snow: 72%
Snow per year: 9.3"

ShareX Facebook WhatsApp Email

Frost risk by date in Blaine

Half of springs at Blaine, WA see their last 32°F night by March 31; only one in ten is past it by March 8, and one in ten still has one after April 22. Planting tender crops after April 7 leaves a 30% risk of a frost on them, after April 12 20%, and after April 22 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 4 in half of years, as early as October 18 one year in ten, and holds off past November 24 one year in ten. A hard freeze of 28°F follows 15 days later, around November 19; in spring the one-in-ten date for 28°F is March 31, 22 days before the 32°F one. The freeze-free season lasts 219 days in a typical year, longer than at 72% of the 113 Washington stations; it reaches 247 days one year in ten and falls short of 190 one year in ten. On average 52 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 23 days longer, to about April 23, and return around October 20. Nights of 24°F, cold enough to damage hardier plants, come in 97% of winters and 16°F in 36%.

Spring: the chance of another night this cold after the date
Low	90%	80%	70%	60%	50%	40%	30%	20%	10%
36°F	Apr 1	Apr 7	Apr 12	Apr 17	Apr 23	Apr 28	May 1	May 4	May 12
32°F	Mar 8	Mar 15	Mar 21	Mar 26	Mar 31	Apr 3	Apr 7	Apr 12	Apr 22
28°F	Feb 2	Feb 17	Feb 25	Feb 28	Mar 5	Mar 10	Mar 15	Mar 21	Mar 31
24°F97% of yrs	Jan 2	Jan 12	Jan 23	Jan 31	Feb 10	Feb 18	Feb 25	Feb 28	Mar 8
20°F73% of yrs	Dec 8	Dec 25	Jan 3	Jan 11	Jan 18	Jan 27	Feb 3	Feb 16	Feb 25
16°F36% of yrs	too rare for a date

Fall: the chance the first night this cold has come by the date
Low	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Oct 4	Oct 8	Oct 12	Oct 16	Oct 20	Oct 23	Oct 27	Oct 31	Nov 6
32°F	Oct 18	Oct 24	Oct 29	Nov 1	Nov 4	Nov 8	Nov 12	Nov 17	Nov 24
28°F	Oct 30	Nov 6	Nov 11	Nov 15	Nov 19	Nov 24	Nov 28	Dec 5	Dec 16
24°F97% of yrs	Nov 12	Nov 20	Nov 26	Dec 1	Dec 6	Dec 12	Dec 21	Dec 31	Jan 15
20°F73% of yrs	Nov 25	Dec 1	Dec 6	Dec 13	Dec 23	Dec 30	Jan 7	Jan 17	Feb 1
16°F36% of yrs	too rare for a date

Freeze probabilities 1991–2020 at Blaine, 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 98230 →Compare Blaine with another place →

Frost risk through the year in Blaine

Frost curve for Blaine, Washington (Blaine, WA, NOAA 1991–2020): the chance of another 32°F night falls from 90% on March 8 to 50% on March 31 and 10% on April 22; the chance that the first fall one has come rises from 10% on October 18 to 50% on November 4 and 90% on November 24. — In Blaine, the spring curve drops under 10% on April 22 and the fall curve passes 10% on October 18, 179 days later; that gap is longer than at 72% of the 113 Washington stations with frost dates. The spring risk falls from 90% to 10% over 45 days (March 8 to April 22) and the fall risk climbs from 10% to 90% over 37 days (October 18 to November 24): both ends of the season vary about as much. At Bellingham International Airport, WA, 15 miles southeast, the same gap runs from April 18 to October 12, 2 days shorter.

Chance of a frost after each planting date in Blaine
Planted on	Another 32°F night	28°F night
Mar 17	77%	27%
Mar 24	64%	17%
Mar 3150% date	50%	under 10%
Apr 7	30%	under 10%
Apr 14	18%	under 10%
Apr 21	11%	under 10%

Weather by month in Blaine

July is the warmest month at Blaine, WA, averaging 73°F by day and 55°F at night; December is the coldest at 44°F and 34°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 44% of years.

Warmth for growing adds up to 1,754 growing degree days a year (base 50°F), fewer than at 72% of the 113 Washington stations. 31% of them (550) have built up by the end of June, and July adds the most, 432. Precipitation totals 41.8 inches a year, most in January (6.2") and least in July (1.1"); May to September bring 21% of it.

Monthly normals 1991–2020 at Blaine, WA
Month	High °F	Low °F	Precip. in	32°F night	Nights ≤ 32°F	GDD 50°F
Jan	45	34	6.2	100%	12	1
Feb	48	35	3.4	98%	11	2
Mar	52	38	4.2	94%	7	9
Apr	58	42	3.0	44%	2	46
May	64	47	2.6	4%	<1	183
Jun	69	52	1.9	0%	<1	309
Jul	73	55	1.1	0%	0	432
Aug	73	55	1.1	0%	0	428
Sep	67	50	2.2	0%	0	261
Oct	57	44	4.4	37%	1	71
Nov	50	38	6.1	93%	7	10
Dec	44	34	5.6	100%	13	2

Monthly normals 1991–2020 at Blaine, WA (60 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, Bellingham International Airport, WA, 15 miles southeast of Blaine, has the same 50% last-frost date, a first frost 5 days earlier (October 30), a season 8 days shorter.

Frost dates for 98248 (Ferndale) →

When it snows in Blaine, Washington

The first measurable snow (0.1 inch or more) in Blaine usually arrives around December 23, and the last of the season around February 21. Those are the middle dates across the winters of 1991–2020 at Blaine, WA, 2.8 miles away: half of years saw snow earlier, half later. Snow fell in 72% of those winters. The last 32°F night of spring typically comes 38 days after the last snow.

Planting calendar for 98230

What to do and when, from the 50% frost dates for Blaine, Washington
When	What to do
January 20 – February 3	Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 3 – February 17	Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 3 – March 17	Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
March 31 onward	Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 12	Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 21	Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
November 4 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 98230 is 3 miles from Blaine, WA, which stands at 60 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 98230 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.

ZIP codes measured at the same station

98240Custer