Florida doesn’t have one frost date. It has one published frost window, measured at a single Jacksonville station, and a huge stretch of the state where that window simply doesn’t apply. The only NOAA-sourced numbers available here put the last spring frost between February 16 and March 7, and the first fall frost between November 26 and December 13. That’s north Florida. Central and south Florida run on a different calendar entirely.
The frost dates for Florida
The dates above come from NOAA’s National Centers for Environmental Information, using 1991-2020 climate normals for station USW00013889, Jacksonville International Airport. NOAA calculates freeze probability at 32°F and reports the window where that probability sits between 30% and 70% across the historical record. In plain terms: sometime in that three-week spring window, and again in that fall window, there’s a real but not certain chance of freezing temperatures.
Here’s the part most people miss. Over the thirty years in that dataset, three autumns at this station never recorded a freeze at all. That’s not a rounding error, it’s roughly one year in ten where the “first fall frost” simply didn’t happen. So even at this single station, the dates describe a probability, not a promise.
| Event | Earliest date | Latest date |
|---|---|---|
| Last spring frost | February 16 | March 7 |
| First fall frost | November 26 | December 13 |
Now the geography problem. Jacksonville sits at the northern edge of the state, inland, at an airport site with open exposure, exactly the kind of location that tends to record colder extremes than a coastal or urban site nearby. That already makes this window a north Florida figure, not a statewide one. Push south past Orlando, and further still to Miami or the Keys, and freezing temperatures become rare enough that a meaningful frost-date range hasn’t been published for those areas at all. The growing calendar there doesn’t shift later, it inverts: winter becomes the productive season, and summer heat becomes the limiting factor.
The USDA Plant Hardiness Zone Map, built from 1991-2020 normals, places Florida across zones 8b to 11b. That’s the widest hardiness range of nearly any state on the map, and it’s built on one variable only, the average annual extreme minimum temperature, not on frost timing. A gardener in the panhandle and a gardener in the Keys are gardening in different climates entirely, even though they share a state line.
How long the growing season actually is here
Do the math on the Jacksonville window and something striking shows up. Counting from the earliest possible last spring frost, February 16, to the earliest possible first fall frost, November 26, gives roughly 283 days without frost. Run the later end of both windows, March 7 to December 13, and you still get about 281 days. Either way, north Florida’s frost-free stretch runs close to nine and a half months.
That’s an unusually long season by national standards, and it’s the reason north Florida gardeners can often get two full plantings of a warm-season crop into a single year, spring and again in late summer for a fall harvest. A tomato that needs 75 days to mature has plenty of room on either side of that window.
Why this number breaks down further south
The 280-plus-day figure only describes the Jacksonville station. Move into central Florida and the frost threat shrinks further; move into south Florida and it largely disappears from the calendar altogether. No published frost-date range exists for those regions in this dataset, because freeze events there are rare enough that NOAA’s 30-70% probability band doesn’t produce a meaningful window.
What replaces it isn’t a longer frost-free season, it’s a different growing season altogether. Gardeners in Orlando or Miami plant many crops through fall, winter, and spring, then slow down or stop through the hottest, most humid stretch of summer, when heat stress and pest pressure do what frost does further north. Treating a south Florida garden with a north Florida frost calendar leads to planting decisions built on the wrong risk entirely.
The practical takeaway: the 280-day figure is real, it’s sourced, and it applies specifically to the Jacksonville area and places with a similar inland north Florida climate. It is not a stand-in for the rest of the state.
Turning these dates into a sowing date
Once you know which end of the state you’re gardening in, the frost window becomes a planning tool. For north Florida gardeners working from the Jacksonville dates, the spring window itself, February 16 to March 7, is the anchor for two different decisions: when to start seeds indoors, and when it’s safe to move tender transplants outside.
As a general rule of thumb in home gardening, many warm-season crops such as tomatoes, peppers, and eggplant are started indoors roughly six to eight weeks before the expected last frost, then hardened off and transplanted once frost risk has passed. Applied to this window, that puts indoor seed-starting somewhere in late December through mid-January, with transplanting timed to whichever end of the February 16 to March 7 range matches your comfort with risk.
Picking an end of the range
A gardener who can cover plants or bring containers indoors on short notice might push transplanting toward the early end, February 16, and gain a few extra weeks of growing time. A gardener without that flexibility, or planting directly in the ground with no easy protection, is better served waiting toward March 7, accepting a shorter season in exchange for fewer losses.
Fall planting works in reverse. Count backward from the first fall frost window, November 26 to December 13, to figure out the last realistic date for a warm-season crop to mature before cold arrives. Cool-season crops like broccoli, collards, and kale flip that logic: they’re often planted specifically to mature through and after that frost window, since a light freeze tends to improve flavor in several of these crops rather than damage them.
For a planting calendar built around your specific county rather than a single Jacksonville station, the University of Florida’s IFAS Extension network keeps localized guidance for home gardeners. That’s worth checking before locking in a date, especially outside the immediate Jacksonville area.
Why your own garden differs from this figure
The Jacksonville station sits at an airport: open, inland, and exposed, with nothing to hold heat overnight the way a dense residential neighborhood does. That single detail explains a lot of the gap between the published dates and what actually happens in a nearby backyard.
Urban and suburban lots tend to run warmer than open airport sites, sometimes by several degrees on a clear, calm night, simply because pavement, buildings, and clustered structures retain heat. A garden tucked against a south-facing wall, or shielded by a fence line, can dodge a light frost that hits an open field a few miles away without any protection at all.
Elevation and drainage matter just as much. Cold air is dense and sinks, so it pools in low spots, ditches, and the bottoms of slopes, while gardens on higher ground or near a slope’s edge often stay several degrees warmer on the coldest nights. Proximity to water works similarly: a garden near a large lake, river, or the coast benefits from water’s slower temperature swings, while an inland garden a short drive away can see a harder frost the same night.
Tree canopy adds another layer. A open sky lets heat radiate away from soil and plants overnight, which is exactly what produces a hard frost; a garden under partial canopy, or near overhead structures, loses less heat and often runs a degree or two warmer at ground level.
None of this means the Jacksonville numbers are wrong. It means they describe one specific site, and a home garden a few miles away, at different elevation, with different exposure, can reasonably run a week or more ahead of or behind that published window in either direction.
Common questions
Does the Jacksonville frost window apply to Orlando or Miami?
No. Those areas are considerably farther south and effectively frost-free most years. No published frost-date range exists for them in this dataset, and their growing calendar runs on a different logic, built around summer heat rather than winter cold.
If three of the last thirty falls at this station had no freeze, why plant around a frost date at all?
Because the other roughly nine years in ten did see one. The window describes the range where freeze probability sits between 30% and 70%, which means real risk on either side of it too. Treat the dates as a planning guide for risk, not a guarantee either way.
What does Florida’s USDA hardiness zone range of 8b to 11b actually tell a gardener?
It describes the average annual extreme minimum temperature at a location, which affects what perennial plants can survive winter there. It says nothing about frost timing in a given year, which is why the hardiness zone and the frost-date window are two separate pieces of information, not one.
How long is the frost-free growing season in north Florida?
Based on the Jacksonville station’s last spring frost and first fall frost windows, it runs roughly 280 to 283 days, close to nine and a half months. That figure is specific to north Florida’s climate and station location, not a statewide average.