USDA Hardiness Zone 9a
Frost Dates for 97141 — Tillamook, Oregon
NOAA 1991–2020 normals from Tillamook, OR (12 ft), 2 miles west.
Updated
In Tillamook, the last spring frost (32°F) is around April 22 in half of years and has passed by May 13 in nine years out of ten. The first fall frost comes around October 21, as early as September 27 one year in ten, leaving a typical freeze-free season of 183 days (NOAA, Tillamook, OR).
- Last spring frost
- April 22
- First fall frost
- October 21
- Growing season
- 183 days
- Hardiness zone
- 9a
50% probability
50% probability
freeze-free, 50%
20 to 25°F (-6.7 to -3.9°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 15%
- Snow per year
- 0.2"
median, 1991–2020
median, 1991–2020
4 of 26 observed
NOAA normal
Frost risk by date in Tillamook
Half of springs at Tillamook, OR see their last 32°F night by April 22; only one in ten is past it by March 28, and one in ten still has one after May 13. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 6 20%, and after May 13 10%. The 21 days between the even-odds date and the one-in-ten date is narrower than at 55% of the 103 Oregon 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 October 21 in half of years, as early as September 27 one year in ten, and holds off past November 15 one year in ten. A hard freeze of 28°F follows 25 days later, around November 15; in spring the one-in-ten date for 28°F is April 20, 23 days before the 32°F one. The freeze-free season lasts 183 days in a typical year, shorter than at 61% of the 103 Oregon stations; it reaches 216 days one year in ten and falls short of 151 one year in ten. On average 47 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 May 15, and return around September 30. Nights of 24°F, cold enough to damage hardier plants, come in 86% of winters and 16°F in 10%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 26 | Apr 30 | May 6 | May 10 | May 15 | May 21 | May 27 | May 31 | Jun 5 |
| 32°F | Mar 28 | Apr 5 | Apr 12 | Apr 17 | Apr 22 | Apr 28 | May 2 | May 6 | May 13 |
| 28°F | Feb 22 | Mar 4 | Mar 11 | Mar 17 | Mar 22 | Mar 28 | Apr 1 | Apr 8 | Apr 20 |
| 24°F86% of yrs | Dec 17 | Jan 2 | Jan 14 | Jan 29 | Feb 10 | Feb 18 | Feb 25 | Mar 2 | Mar 15 |
| 20°F36% of yrs | too rare for a date | ||||||||
| 16°F10% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 7 | Sep 14 | Sep 21 | Sep 26 | Sep 30 | Oct 3 | Oct 6 | Oct 12 | Oct 19 |
| 32°F | Sep 27 | Oct 3 | Oct 9 | Oct 15 | Oct 21 | Oct 26 | Nov 1 | Nov 7 | Nov 15 |
| 28°F | Oct 21 | Oct 30 | Nov 2 | Nov 9 | Nov 15 | Nov 23 | Dec 1 | Dec 6 | Dec 18 |
| 24°F86% of yrs | Nov 5 | Nov 17 | Nov 30 | Dec 5 | Dec 11 | Dec 21 | Jan 1 | Jan 16 | Feb 10 |
| 20°F36% of yrs | too rare for a date | ||||||||
| 16°F10% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Tillamook, OR, 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 97141 →Compare Tillamook with another place →
Weather by month in Tillamook
August is the warmest month at Tillamook, OR, averaging 69°F by day and 50°F at night; December is the coldest at 51°F and 36°F. A freezing night is all but certain in every month from December to March (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 77% of years and May still brings one in 31% of years.
Warmth for growing adds up to 1,314 growing degree days a year (base 50°F), fewer than at 95% of the 103 Oregon stations. 27% of them (353) have built up by the end of June, and August adds the most, 299. Precipitation totals 90.0 inches a year, most in December (14.7") and least in July (0.9"); May to September bring 15% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 52 | 37 | 13.4 | 96% | 9 | 12 |
| Feb | 53 | 36 | 9.5 | 97% | 9 | 11 |
| Mar | 55 | 37 | 10.1 | 97% | 8 | 20 |
| Apr | 57 | 39 | 7.5 | 77% | 3 | 33 |
| May | 61 | 44 | 4.6 | 31% | 1 | 98 |
| Jun | 64 | 48 | 3.3 | 0% | 0 | 179 |
| Jul | 68 | 50 | 0.9 | 0% | 0 | 279 |
| Aug | 69 | 50 | 1.2 | 0% | 0 | 299 |
| Sep | 68 | 47 | 3.6 | 13% | <1 | 230 |
| Oct | 63 | 43 | 7.8 | 64% | 2 | 111 |
| Nov | 56 | 39 | 13.4 | 88% | 7 | 33 |
| Dec | 51 | 36 | 14.7 | 99% | 9 | 9 |
Monthly normals 1991–2020 at Tillamook, OR (12 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, Cloverdale, OR, 18 miles south of Tillamook, has a last frost 36 days earlier (March 17), a first frost 32 days later (November 22), a season 68 days longer.
When it snows in Tillamook, Oregon
Measurable snow is rare here: only 4 of 26 winters from 1991 to 2020 recorded 0.1 inch or more at Tillamook, OR, 2.4 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 97141
| 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 29 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 7 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 21 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 97141 is 2 miles from Tillamook, OR, which stands at 12 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 97141 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.
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.