USDA Hardiness Zone 5a
Frost Dates for 83455 — Victor, Idaho
NOAA 1991–2020 normals from Driggs, ID (6,120 ft), 7 miles north.
Updated
In Victor, the last spring frost (32°F) is around June 13 in half of years and has passed by June 28 in nine years out of ten. The first fall frost comes around September 9, as early as August 26 one year in ten, leaving a typical freeze-free season of 86 days (NOAA, Driggs, ID).
- Last spring frost
- June 13
- First fall frost
- September 9
- Growing season
- 86 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- November 2
- Last snow
- April 11
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
22 of 22 observed
NOAA normal
Frost risk by date in Victor
Half of springs at Driggs, ID see their last 32°F night by June 13; only one in ten is past it by May 27, and one in ten still has one after June 28. Planting tender crops after June 20 leaves a 30% risk of a frost on them, after June 23 20%, and after June 28 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 78% of the 67 Idaho stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 9 in half of years, as early as August 26 one year in ten, and holds off past September 23 one year in ten. A hard freeze of 28°F follows 11 days later, around September 20; in spring the one-in-ten date for 28°F is June 11, 17 days before the 32°F one. The freeze-free season lasts 86 days in a typical year, shorter than at 97% of the 67 Idaho stations; it reaches 108 days one year in ten and falls short of 64 one year in ten. On average 204 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between October 26 and April 8.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | May 27 | Jun 2 | Jun 5 | Jun 9 | Jun 13 | Jun 16 | Jun 20 | Jun 23 | Jun 28 |
| 28°F | May 5 | May 10 | May 14 | May 18 | May 22 | May 28 | Jun 1 | Jun 5 | Jun 11 |
| 24°F | Apr 21 | Apr 27 | Apr 30 | May 2 | May 5 | May 8 | May 11 | May 16 | May 24 |
| 20°F | Apr 7 | Apr 12 | Apr 15 | Apr 19 | Apr 23 | Apr 27 | Apr 30 | May 3 | May 10 |
| 16°F | Mar 24 | Mar 30 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 15 | Apr 21 | Apr 27 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | Aug 26 | Aug 30 | Sep 2 | Sep 5 | Sep 9 | Sep 11 | Sep 14 | Sep 18 | Sep 23 |
| 28°F | Sep 4 | Sep 9 | Sep 13 | Sep 17 | Sep 20 | Sep 23 | Sep 27 | Sep 30 | Oct 4 |
| 24°F | Sep 14 | Sep 21 | Sep 26 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 12 | Oct 16 |
| 20°F | Sep 28 | Oct 2 | Oct 6 | Oct 10 | Oct 13 | Oct 17 | Oct 21 | Oct 25 | Oct 31 |
| 16°F | Oct 7 | Oct 14 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 9 |
Freeze probabilities 1991–2020 at Driggs, ID, 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 83455 →Compare Victor with another place →
Weather by month in Victor
July is the warmest month at Driggs, ID, averaging 83°F by day and 48°F at night; January is the coldest at 33°F and 9°F. A freezing night is all but certain in every month from September to May (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 83% of years.
Warmth for growing adds up to 1,458 growing degree days a year (base 50°F), fewer than at 96% of the 67 Idaho stations. 23% of them (335) have built up by the end of June, and July adds the most, 471.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 33 | 9 | 100% | 31 | 0 |
| Feb | 36 | 12 | 100% | 27 | 0 |
| Mar | 44 | 20 | 100% | 27 | 0 |
| Apr | 54 | 28 | 100% | 22 | 12 |
| May | 65 | 35 | 100% | 11 | 90 |
| Jun | 73 | 41 | 83% | 3 | 233 |
| Jul | 83 | 48 | 6% | 0 | 471 |
| Aug | 82 | 46 | 23% | <1 | 426 |
| Sep | 73 | 38 | 97% | 6 | 195 |
| Oct | 58 | 29 | 100% | 20 | 30 |
| Nov | 44 | 19 | 100% | 27 | 1 |
| Dec | 33 | 11 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Driggs, ID (6,120 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, Tetonia Exp Stn, ID, 17 miles northwest of Victor, has a last frost 2 days later (June 15), a first frost 2 days earlier (September 7), a season 1 day shorter.
When it snows in Victor, Idaho
The first measurable snow (0.1 inch or more) in Victor usually arrives around November 2, and the last of the season around April 11. Those are the middle dates across the winters of 1991–2020 at Driggs, ID, 6.8 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 63 days after the last snow.
Planting calendar for 83455
| When | What to do |
|---|---|
| April 4 – April 18 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| April 18 – May 2 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| May 16 – May 30 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| June 13 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by June 17 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by August 26 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 9 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 83455 is 7 miles from Driggs, ID, which stands at 6,120 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 83455 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°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.