USDA Hardiness Zone 9a
Frost Dates for 97368 — Otis, Oregon
NOAA 1991–2020 normals from Otis 2 NE, OR (150 ft), 2 miles north.
Updated
In Otis, the last spring frost (32°F) is around April 4 in half of years and has passed by May 3 in nine years out of ten. The first fall frost comes around November 16, as early as October 26 one year in ten, leaving a typical freeze-free season of 227 days (NOAA, Otis 2 NE, OR).
- Last spring frost
- April 4
- First fall frost
- November 16
- Growing season
- 227 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
- 4%
- Snow per year
- 0.1"
median, 1991–2020
median, 1991–2020
1 of 27 observed
NOAA normal
Frost risk by date in Otis
Half of springs at Otis 2 NE, OR see their last 32°F night by April 4; only one in ten is past it by March 2, and one in ten still has one after May 3. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 27 20%, and after May 3 10%. The 29 days between the even-odds date and the one-in-ten date is wider than at 82% 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 November 16 in half of years, as early as October 26 one year in ten, and holds off past December 12 one year in ten. A hard freeze of 28°F follows 22 days later, around December 8; in spring the one-in-ten date for 28°F is March 24, 40 days before the 32°F one. The freeze-free season lasts 227 days in a typical year, longer than at 71% of the 103 Oregon stations; it reaches 264 days one year in ten and falls short of 189 one year in ten. On average 32 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 29 days longer, to about May 3, and return around October 25. A 24°F night is unusual: 48% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 15 | Apr 22 | Apr 27 | Apr 30 | May 3 | May 7 | May 11 | May 15 | May 22 |
| 32°F | Mar 2 | Mar 19 | Mar 25 | Mar 31 | Apr 4 | Apr 11 | Apr 18 | Apr 27 | May 3 |
| 28°F94% of yrs | Dec 26 | Jan 12 | Jan 29 | Feb 8 | Feb 18 | Feb 25 | Mar 2 | Mar 12 | Mar 24 |
| 24°F48% of yrs | too rare for a date | ||||||||
| 20°F16% of yrs | too rare for a date | ||||||||
| 16°F3% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 4 | Oct 11 | Oct 17 | Oct 21 | Oct 25 | Oct 29 | Nov 1 | Nov 6 | Nov 14 |
| 32°F | Oct 26 | Nov 1 | Nov 8 | Nov 12 | Nov 16 | Nov 22 | Nov 27 | Dec 2 | Dec 12 |
| 28°F94% of yrs | Nov 10 | Nov 17 | Nov 26 | Dec 1 | Dec 8 | Dec 16 | Dec 25 | Jan 5 | Jan 30 |
| 24°F48% of yrs | too rare for a date | ||||||||
| 20°F16% of yrs | too rare for a date | ||||||||
| 16°F3% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Otis 2 NE, 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 97368 →Compare Otis with another place →
Weather by month in Otis
August is the warmest month at Otis 2 NE, OR, averaging 72°F by day and 52°F at night; December is the coldest at 48°F and 37°F. A freezing night is all but certain in December (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month.
Warmth for growing adds up to 1,601 growing degree days a year (base 50°F), fewer than at 84% of the 103 Oregon stations. 28% of them (446) have built up by the end of June, and August adds the most, 370. Precipitation totals 96.5 inches a year, most in December (15.9") and least in July (0.9"); May to September bring 14% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 49 | 38 | 14.6 | 89% | 8 | 6 |
| Feb | 52 | 38 | 10.5 | 89% | 6 | 8 |
| Mar | 55 | 39 | 10.8 | 76% | 5 | 21 |
| Apr | 59 | 41 | 8.2 | 51% | 2 | 49 |
| May | 63 | 45 | 4.7 | 14% | <1 | 138 |
| Jun | 66 | 49 | 3.5 | 0% | 0 | 224 |
| Jul | 71 | 51 | 0.9 | 0% | 0 | 343 |
| Aug | 72 | 52 | 1.4 | 0% | 0 | 370 |
| Sep | 70 | 49 | 3.4 | 0% | 0 | 288 |
| Oct | 61 | 45 | 8.5 | 17% | <1 | 120 |
| Nov | 53 | 41 | 14.1 | 71% | 3 | 26 |
| Dec | 48 | 37 | 15.9 | 95% | 8 | 8 |
Monthly normals 1991–2020 at Otis 2 NE, OR (150 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, 14 miles north of Otis, has a last frost 18 days earlier (March 17), a first frost 6 days later (November 22), a season 24 days longer.
When it snows in Otis, Oregon
Measurable snow is rare here: only 1 of 27 winters from 1991 to 2020 recorded 0.1 inch or more at Otis 2 NE, OR, 1.7 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 97368
| When | What to do |
|---|---|
| January 24 – February 7 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 7 – February 21 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 7 – March 21 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 4 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 24 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 2 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 16 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 97368 is 2 miles from Otis 2 NE, OR, which stands at 150 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 97367 (Lincoln City). The 2023 USDA Plant Hardiness Zone Map lists ZIP 97368 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.