USDA Hardiness Zone 9a
Frost Dates for 32011 — Callahan, Florida
NOAA 1991–2020 normals from Jacksonville, FL (33 ft), 10 miles southeast.
Updated
In Callahan, the last spring frost (32°F) is around February 25 in half of years and has passed by March 19 in nine years out of ten. The first fall frost comes around December 7, as early as November 17 one year in ten, leaving a typical freeze-free season of 288 days (NOAA, Jacksonville, FL).
- Last spring frost
- February 25
- First fall frost
- December 7
- Growing season
- 288 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
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 16 observed
NOAA normal
Frost risk by date in Callahan
Half of springs at Jacksonville, FL see their last 32°F night by February 25; only one in ten is past it by January 22, and one in ten still has one after March 19. Planting tender crops after March 7 leaves a 30% risk of a frost on them, after March 12 20%, and after March 19 10%. The 22 days between the even-odds date and the one-in-ten date is narrower than at 66% of the 101 Florida 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 December 7 in half of years, as early as November 17 one year in ten, and holds off past January 10 one year in ten. A hard freeze of 28°F follows 26 days later, around January 2; in spring the one-in-ten date for 28°F is March 4, 15 days before the 32°F one. The freeze-free season lasts 288 days in a typical year, shorter than at 58% of the 102 Florida stations; it reaches 326 days one year in ten and falls short of 256 one year in ten. On average 14 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 16 days longer, to about March 13, and return around November 22. A 24°F night is unusual: 48% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 19 | Feb 28 | Mar 5 | Mar 9 | Mar 13 | Mar 16 | Mar 20 | Mar 25 | Apr 1 |
| 32°F | Jan 22 | Feb 4 | Feb 13 | Feb 19 | Feb 25 | Mar 2 | Mar 7 | Mar 12 | Mar 19 |
| 28°F87% of yrs | Jan 4 | Jan 15 | Jan 22 | Jan 30 | Feb 4 | Feb 10 | Feb 17 | Feb 26 | Mar 4 |
| 24°F48% of yrs | too rare for a date | ||||||||
| 20°F12% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 7 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 26 | Dec 1 | Dec 4 | Dec 13 |
| 32°F | Nov 17 | Nov 23 | Nov 29 | Dec 3 | Dec 7 | Dec 12 | Dec 22 | Jan 1 | Jan 10 |
| 28°F87% of yrs | Nov 29 | Dec 5 | Dec 13 | Dec 26 | Jan 2 | Jan 7 | Jan 13 | Jan 20 | Feb 3 |
| 24°F48% of yrs | too rare for a date | ||||||||
| 20°F12% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Jacksonville, FL, 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 32011 →Compare Callahan with another place →
Weather by month in Callahan
July is the warmest month at Jacksonville, FL, averaging 92°F by day and 73°F at night; January is the coldest at 66°F and 43°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 69% of years and March still brings one in 42% of years.
Warmth for growing adds up to 7,193 growing degree days a year (base 50°F), fewer than at 76% of the 158 Florida stations. 42% of them (3,045) have built up by the end of June, and July adds the most, 1,009. Precipitation totals 53.5 inches a year, most in June (7.6") and least in November (2.0"); May to September bring 60% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 66 | 43 | 3.3 | 86% | 6 | 193 |
| Feb | 69 | 46 | 2.9 | 69% | 3 | 235 |
| Mar | 74 | 51 | 3.3 | 42% | 1 | 394 |
| Apr | 80 | 56 | 2.9 | 1% | 0 | 543 |
| May | 86 | 64 | 3.4 | 0% | 0 | 772 |
| Jun | 90 | 71 | 7.6 | 0% | 0 | 909 |
| Jul | 92 | 73 | 6.8 | 0% | 0 | 1009 |
| Aug | 91 | 73 | 6.9 | 0% | 0 | 995 |
| Sep | 87 | 71 | 7.6 | 0% | 0 | 865 |
| Oct | 81 | 62 | 4.0 | 0% | 0 | 657 |
| Nov | 73 | 51 | 2.0 | 33% | 1 | 375 |
| Dec | 68 | 46 | 2.8 | 67% | 4 | 246 |
Monthly normals 1991–2020 at Jacksonville, FL (33 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, Jackson Whitehouse Nolf, FL, 15 miles south of Callahan, has a last frost 3 days later (February 28), a first frost 4 days earlier (December 3), a season 8 days shorter.
When it snows in Callahan, Florida
Measurable snow is rare here: only 0 of 16 winters from 1991 to 2020 recorded 0.1 inch or more at Jacksonville, FL, 10.1 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 32011
| When | What to do |
|---|---|
| December 17 – December 31 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 31 – January 14 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| January 28 – February 11 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| February 25 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 14 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 23 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 7 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 32011 is 10 miles from Jacksonville, FL, which stands at 33 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 32218 (Jacksonville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 32011 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.