USDA Hardiness Zone 5a
Frost Dates for 83638 — Mccall, Idaho
NOAA 1991–2020 normals from Mccall Airport, ID (5,013 ft), 4 miles northwest.
Updated
In Mccall, the last spring frost (32°F) is around June 10 in half of years and has passed by June 28 in nine years out of ten. The first fall frost comes around September 10, as early as August 29 one year in ten, leaving a typical freeze-free season of 93 days (NOAA, Mccall Airport, ID).
- Last spring frost
- June 10
- First fall frost
- September 10
- Growing season
- 93 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 18
- Winters with snow
- 100%
- Snow per year
- 132.2"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Mccall
Half of springs at Mccall Airport, ID see their last 32°F night by June 10; only one in ten is past it by May 21, and one in ten still has one after June 28. Planting tender crops after June 17 leaves a 30% risk of a frost on them, after June 21 20%, and after June 28 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 42% of the 67 Idaho stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 10 in half of years, as early as August 29 one year in ten, and holds off past September 25 one year in ten. A hard freeze of 28°F follows 15 days later, around September 25; in spring the one-in-ten date for 28°F is June 6, 22 days before the 32°F one. The freeze-free season lasts 93 days in a typical year, shorter than at 94% of the 67 Idaho stations; it reaches 116 days one year in ten and falls short of 70 one year in ten. On average 224 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between November 4 and April 2.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | May 21 | May 28 | Jun 2 | Jun 6 | Jun 10 | Jun 14 | Jun 17 | Jun 21 | Jun 28 |
| 28°F | Apr 30 | May 5 | May 9 | May 12 | May 15 | May 19 | May 24 | May 31 | Jun 6 |
| 24°F | Apr 12 | Apr 19 | Apr 22 | Apr 25 | Apr 28 | May 1 | May 3 | May 8 | May 13 |
| 20°F | Mar 31 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 20 | Apr 24 | Apr 29 |
| 16°F | Mar 15 | Mar 22 | Mar 27 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 11 | Apr 16 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | Aug 29 | Sep 2 | Sep 5 | Sep 8 | Sep 10 | Sep 13 | Sep 17 | Sep 21 | Sep 25 |
| 28°F | Sep 10 | Sep 15 | Sep 19 | Sep 22 | Sep 25 | Sep 28 | Oct 1 | Oct 4 | Oct 9 |
| 24°F | Sep 24 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 12 | Oct 15 | Oct 19 | Oct 24 |
| 20°F | Oct 6 | Oct 12 | Oct 17 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 3 | Nov 9 |
| 16°F | Oct 20 | Oct 25 | Oct 29 | Nov 1 | Nov 4 | Nov 8 | Nov 11 | Nov 15 | Nov 21 |
Freeze probabilities 1991–2020 at Mccall Airport, 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 83638 →Compare Mccall with another place →
Weather by month in Mccall
July is the warmest month at Mccall Airport, ID, averaging 81°F by day and 47°F at night; December is the coldest at 30°F and 14°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 72% of years.
Warmth for growing adds up to 1,290 growing degree days a year (base 50°F), fewer than at 99% of the 67 Idaho stations. 20% of them (262) have built up by the end of June, and July adds the most, 438. Precipitation totals 23.0 inches a year, most in December (2.8") and least in August (0.5"); May to September bring 28% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 31 | 14 | 2.5 | 100% | 31 | 0 |
| Feb | 35 | 15 | 2.3 | 100% | 28 | 0 |
| Mar | 42 | 21 | 2.7 | 100% | 30 | 0 |
| Apr | 50 | 28 | 2.4 | 100% | 26 | 5 |
| May | 61 | 36 | 2.3 | 100% | 13 | 70 |
| Jun | 69 | 42 | 2.0 | 72% | 4 | 187 |
| Jul | 81 | 47 | 0.6 | 8% | <1 | 438 |
| Aug | 81 | 45 | 0.5 | 15% | 1 | 403 |
| Sep | 71 | 38 | 1.0 | 95% | 9 | 169 |
| Oct | 56 | 29 | 1.6 | 100% | 24 | 19 |
| Nov | 40 | 21 | 2.3 | 100% | 28 | 0 |
| Dec | 30 | 14 | 2.8 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Mccall Airport, ID (5,013 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, Council, ID, 20 miles west of Mccall and 2,070 feet lower, has a last frost 31 days earlier (May 10), a first frost 22 days later (October 2), a season 52 days longer.
When it snows in Mccall, Idaho
The first measurable snow (0.1 inch or more) in Mccall usually arrives around November 2, and the last of the season around April 18. Those are the middle dates across the winters of 1991–2020 at Mccall, ID, 3.5 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 53 days after the last snow.
Planting calendar for 83638
| When | What to do |
|---|---|
| April 1 – April 15 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| April 15 – April 29 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| May 13 – May 27 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| June 10 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by June 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by August 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 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 83638 is 4 miles from Mccall Airport, ID, which stands at 5,013 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 83638 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.