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USDA Hardiness Zone 6b

Frost Dates for 83850 — Pinehurst, Idaho

NOAA 1991–2020 normals from Kellogg, ID (2,377 ft), 6 miles east.

Updated

In Pinehurst, the last spring frost (32°F) is around May 14 in half of years and has passed by June 3 in nine years out of ten. The first fall frost comes around September 26, as early as September 9 one year in ten, leaving a typical freeze-free season of 131 days (NOAA, Kellogg, ID).

Last spring frost
May 14

50% probability

First fall frost
September 26

50% probability

Growing season
131 days

freeze-free, 50%

Hardiness zone
6b

-5 to 0°F (-20.6 to -17.8°C) coldest night

First snow
November 22

median, 1991–2020

Last snow
March 24

median, 1991–2020

Winters with snow
100%

26 of 26 observed

Snow per year
52.4"

NOAA normal

Frost risk by date in Pinehurst

Half of springs at Kellogg, ID see their last 32°F night by May 14; only one in ten is past it by April 30, and one in ten still has one after June 3. Planting tender crops after May 21 leaves a 30% risk of a frost on them, after May 26 20%, and after June 3 10%. The 20 days between the even-odds date and the one-in-ten date is wider than at 69% of the 67 Idaho stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 26 in half of years, as early as September 9 one year in ten, and holds off past October 9 one year in ten. A hard freeze of 28°F follows 12 days later, around October 8; in spring the one-in-ten date for 28°F is May 13, 21 days before the 32°F one. The freeze-free season lasts 131 days in a typical year, shorter than at 67% of the 67 Idaho stations; it reaches 152 days one year in ten and falls short of 106 one year in ten. On average 147 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 19 days longer, to about June 2, and return around September 10. Severe cold of 16°F or below comes every winter, usually between November 23 and March 2.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FMay 16May 22May 27May 30Jun 2Jun 6Jun 11Jun 16Jun 24
32°FApr 30May 4May 8May 11May 14May 17May 21May 26Jun 3
28°FApr 12Apr 18Apr 23Apr 27Apr 30May 2May 5May 9May 13
24°FMar 18Mar 24Mar 30Apr 2Apr 7Apr 10Apr 15Apr 21Apr 29
20°FFeb 25Mar 3Mar 7Mar 10Mar 14Mar 18Mar 22Mar 28Apr 3
16°FFeb 8Feb 16Feb 22Feb 28Mar 2Mar 5Mar 8Mar 12Mar 17
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FAug 26Sep 1Sep 4Sep 7Sep 10Sep 14Sep 17Sep 22Sep 26
32°FSep 9Sep 15Sep 19Sep 23Sep 26Sep 29Oct 2Oct 5Oct 9
28°FSep 24Sep 30Oct 2Oct 5Oct 8Oct 12Oct 16Oct 20Oct 24
24°FOct 6Oct 13Oct 17Oct 21Oct 24Oct 28Nov 1Nov 6Nov 13
20°FOct 18Oct 24Oct 29Nov 2Nov 8Nov 12Nov 17Nov 22Nov 29
16°FOct 28Nov 5Nov 12Nov 18Nov 23Nov 28Dec 1Dec 6Dec 16

Freeze probabilities 1991–2020 at Kellogg, 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 83850 →Compare Pinehurst with another place →

Weather by month in Pinehurst

July is the warmest month at Kellogg, ID, averaging 85°F by day and 51°F at night; December is the coldest at 36°F and 22°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 87% of years and June still brings one in 13% of years.

Warmth for growing adds up to 1,843 growing degree days a year (base 50°F), fewer than at 76% of the 67 Idaho stations. 28% of them (515) have built up by the end of June, and July adds the most, 549. Precipitation totals 34.1 inches a year, most in November (4.6") and least in August (0.8"); May to September bring 26% of it.

Monthly normals 1991–2020 at Kellogg, ID
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan37224.3100%270
Feb42233.1100%230
Mar50273.7100%222
Apr58322.9100%1128
May69402.987%3171
Jun75462.713%0315
Jul85511.20%0549
Aug84490.83%0514
Sep73411.364%1232
Oct58333.199%1232
Nov44274.6100%201
Dec36223.5100%270

Monthly normals 1991–2020 at Kellogg, ID (2,377 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, Wallace, ID, 15 miles east of Pinehurst and 333 feet higher, has a last frost 9 days earlier (May 5), a first frost 6 days later (October 2), a season 18 days longer.

Frost dates for 83849 (Osburn) →

When it snows in Pinehurst, Idaho

The first measurable snow (0.1 inch or more) in Pinehurst usually arrives around November 22, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Kellogg, ID, 5.8 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 51 days after the last snow.

Planting calendar for 83850

What to do and when, from the 50% frost dates for Pinehurst, Idaho
WhenWhat to do
March 5 – March 19Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 19 – April 2Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
April 16 – April 30Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
May 14 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 4Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by September 12Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
September 26 onwardPlant 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 83850 is 6 miles from Kellogg, ID, which stands at 2,377 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 83837 (Kellogg). The 2023 USDA Plant Hardiness Zone Map lists ZIP 83850 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Idaho →

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

Other zone 6b places in Idaho