USDA Hardiness Zone 8b
Frost Dates for 97362 — Mount Angel, Oregon
NOAA 1991–2020 normals from Silverton, OR (408 ft), 4 miles south.
Updated
In Mount Angel, the last spring frost (32°F) is around March 28 in half of years and has passed by April 19 in nine years out of ten. The first fall frost comes around November 10, as early as October 25 one year in ten, leaving a typical freeze-free season of 227 days (NOAA, Silverton, OR).
- Last spring frost
- March 28
- First fall frost
- November 10
- Growing season
- 227 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
- 44%
- Snow per year
- 1.1"
median, 1991–2020
median, 1991–2020
12 of 27 observed
NOAA normal
Frost risk by date in Mount Angel
Half of springs at Silverton, OR see their last 32°F night by March 28; only one in ten is past it by March 1, and one in ten still has one after April 19. Planting tender crops after April 4 leaves a 30% risk of a frost on them, after April 10 20%, and after April 19 10%. The 22 days between the even-odds date and the one-in-ten date is narrower than at 45% 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 10 in half of years, as early as October 25 one year in ten, and holds off past December 1 one year in ten. A hard freeze of 28°F follows 18 days later, around November 28; in spring the one-in-ten date for 28°F is March 23, 27 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 260 days one year in ten and falls short of 198 one year in ten. On average 44 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 28 days longer, to about April 25, and return around October 26. Nights of 24°F, cold enough to damage hardier plants, come in 86% of winters and 16°F in 18%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 5 | Apr 11 | Apr 16 | Apr 20 | Apr 25 | Apr 28 | May 1 | May 5 | May 11 |
| 32°F | Mar 1 | Mar 10 | Mar 17 | Mar 23 | Mar 28 | Mar 31 | Apr 4 | Apr 10 | Apr 19 |
| 28°F | Jan 18 | Feb 2 | Feb 12 | Feb 19 | Feb 25 | Feb 28 | Mar 5 | Mar 13 | Mar 23 |
| 24°F86% of yrs | Dec 12 | Dec 22 | Jan 1 | Jan 12 | Jan 23 | Feb 2 | Feb 12 | Feb 20 | Feb 26 |
| 20°F48% of yrs | too rare for a date | ||||||||
| 16°F18% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 9 | Oct 15 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 5 | Nov 11 |
| 32°F | Oct 25 | Oct 29 | Nov 2 | Nov 7 | Nov 10 | Nov 13 | Nov 19 | Nov 24 | Dec 1 |
| 28°F | Nov 4 | Nov 10 | Nov 17 | Nov 23 | Nov 28 | Dec 3 | Dec 8 | Dec 14 | Dec 24 |
| 24°F86% of yrs | Nov 15 | Nov 26 | Dec 2 | Dec 7 | Dec 12 | Dec 19 | Dec 28 | Jan 5 | Jan 27 |
| 20°F48% of yrs | too rare for a date | ||||||||
| 16°F18% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Silverton, 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 97362 →Compare Mount Angel with another place →
Weather by month in Mount Angel
August is the warmest month at Silverton, OR, averaging 80°F by day and 56°F at night; December is the coldest at 46°F and 35°F. A freezing night is all but certain in every month from December 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 86% of years and April still brings one in 38% of years.
Warmth for growing adds up to 2,332 growing degree days a year (base 50°F), more than at 59% of the 103 Oregon stations. 29% of them (673) have built up by the end of June, and August adds the most, 552. Precipitation totals 47.3 inches a year, most in December (7.5") and least in July (0.4"); May to September bring 15% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 47 | 35 | 6.7 | 97% | 12 | 5 |
| Feb | 50 | 36 | 4.9 | 95% | 9 | 7 |
| Mar | 55 | 38 | 5.5 | 86% | 4 | 25 |
| Apr | 60 | 42 | 4.2 | 38% | 1 | 72 |
| May | 67 | 47 | 2.9 | 2% | 0 | 219 |
| Jun | 72 | 51 | 1.8 | 0% | 0 | 345 |
| Jul | 80 | 56 | 0.4 | 0% | 0 | 546 |
| Aug | 80 | 56 | 0.5 | 0% | 0 | 552 |
| Sep | 74 | 52 | 1.7 | 0% | 0 | 390 |
| Oct | 63 | 45 | 4.2 | 25% | 1 | 143 |
| Nov | 52 | 39 | 7.0 | 87% | 6 | 24 |
| Dec | 46 | 35 | 7.5 | 100% | 12 | 5 |
Monthly normals 1991–2020 at Silverton, OR (408 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, Aurora State Airport, OR, 13 miles north of Mount Angel and 212 feet lower, has a last frost 12 days earlier (March 16), a first frost 4 days later (November 14), a season 15 days longer.
When it snows in Mount Angel, Oregon
Measurable snow is rare here: only 12 of 27 winters from 1991 to 2020 recorded 0.1 inch or more at Silverton, OR, 4.4 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 97362
| When | What to do |
|---|---|
| January 17 – January 31 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 31 – February 14 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 28 – March 14 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 28 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 97362 is 4 miles from Silverton, OR, which stands at 408 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 97381 (Silverton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 97362 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.
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.