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Reviewed · Prices checked October 2026 · How we calculate

Frost Date Calculator: When Is the Last Frost in My ZIP Code?

Enter your ZIP code. You get the average last spring and first fall frost, how late a frost can come 1 year in 10, and when to start seeds indoors and plant out.

Inputs

Plan around

Average: half of years still get a frost after the last frost date. Safer: only 1 year in 10 does, at the cost of a later start and a shorter season.

Frost dates

Updates as you type
Mar 30last frost

ZIP 10001, New York County, NY: the average last spring frost. The average first fall frost is Nov 20.

Frost dates
Last spring frostMar 30 on average; 1 year in 10 it comes after Apr 9; 1 year in 10 it is over by Mar 14
First fall frostNov 20 on average; 1 year in 10 it comes before Nov 6; 1 year in 10 it holds off past Dec 6
Frost-free season236 days (NOAA median)
Weather stationNY City Cntrl Park weather station, 0 km from the county's center of population
Vegetables and herbs
PlantSow indoorsPlant out
BroccoliJan 19Mar 9
CabbageJan 19Mar 9
CauliflowerJan 19Mar 9
KaleJan 19Mar 9
ParsleyJan 19Mar 9
LettuceFeb 2Mar 2
OnionsJan 19Mar 16
LeeksJan 19Mar 16
PeppersFeb 2Apr 13
EggplantFeb 2Apr 13
TomatoesFeb 16Apr 13
Oregano and marjoramFeb 16Apr 13
BasilMar 9Apr 13
Flowers
PlantSow indoorsPlant out
Pansy and violaJan 19Mar 16
CarnationsJan 19Mar 16
FoxgloveJan 19Mar 16
SnapdragonsFeb 2Mar 16
ColumbineFeb 2 to Feb 16Mar 16
PetuniaJan 19Apr 13
LobeliaJan 19Apr 13
SchizanthusFeb 2Apr 13
MarigoldsFeb 16Apr 20
NicotianaFeb 16Apr 13
StaticeFeb 16Apr 13
StockFeb 16Apr 13
PhloxMar 2Apr 13
Canterbury bellsMar 2 to Mar 16Apr 27 to May 11
DelphiniumMar 2 to Mar 16Apr 27 to May 11
Show the math
Average dates: the 50% chance last spring and first fall frosts (32°F) from NOAA's 1991-2020 normalsTomatoes: sow 6 weeks before Mar 30 = Feb 16; set out 2 weeks after = Apr 13Days between Mar 30 and Nov 20: 235

Your ZIP code is saved on this device only.

How it works

Where the dates come from

  • Frost dates are NOAA's 1991-2020 climate normals for a 32°F freeze: the date with a 50% chance of a later spring frost (the average last frost), and the dates with a 10% and 90% chance.
  • Your station is the NOAA station nearest your county's center of population (2020 Census) with a full record; a few counties where that station sits on a mountain use the one by the main town.
  • Seed-starting dates count back and forward from the last frost using NDSU Extension's Time and Temperature Chart (H-1139). Treat them as a guide: your own garden, the weather that year and the variety all matter.
  • Frost can still settle in low spots on a clear, calm night above 32°F, and tender plants like tomatoes and basil suffer below about 50°F, so many gardeners wait for the safer date.

Worked example

ZIP 10001, New York County, NY

  1. Average last spring frost: Mar 30
  2. Tomatoes: sow indoors 6 weeks before, set out 2 weeks after
  3. Average first fall frost: Nov 20, so 236 frost-free days

When to start seeds, counted from the last frost

Weeks to sow indoors before the last frost and when to plant out
PlantSow indoorsPlant out
Broccoli10 weeks before3 weeks before
Cabbage10 weeks before3 weeks before
Cauliflower10 weeks before3 weeks before
Kale10 weeks before3 weeks before
Parsley10 weeks before3 weeks before
Lettuce8 weeks before4 weeks before
Onions10 weeks before2 weeks before
Leeks10 weeks before2 weeks before
Peppers8 weeks before2 weeks after
Eggplant8 weeks before2 weeks after
Tomatoes6 weeks before2 weeks after
Oregano and marjoram6 weeks before2 weeks after
Basil3 weeks before2 weeks after
Pansy and viola10 weeks before2 weeks before
Carnations10 weeks before2 weeks before
Foxglove10 weeks before2 weeks before
Snapdragons8 weeks before2 weeks before
Columbine6 to 8 weeks before2 weeks before
Petunia10 weeks before2 weeks after
Lobelia10 weeks before2 weeks after
Schizanthus8 weeks before2 weeks after
Marigolds6 weeks before3 weeks after
Nicotiana6 weeks before2 weeks after
Statice6 weeks before2 weeks after
Stock6 weeks before2 weeks after
Phlox4 weeks before2 weeks after
Canterbury bells2 to 4 weeks before4 to 6 weeks after
Delphinium2 to 4 weeks before4 to 6 weeks after

Average frost dates by city

Average last spring and first fall frost and median frost-free season in days by city, NOAA 1991-2020
CityLast frostFirst frostFrost-free season
New YorkMar 30Nov 20236
Los AngelesRareRare365
ChicagoApr 11Oct 31201
HoustonFeb 2Dec 25327
PhoenixJan 5Jan 3365
PhiladelphiaMar 30Nov 17232
San AntonioFeb 25Nov 28277
San DiegoRareRare365
DallasMar 2Nov 29272
AustinFeb 20Dec 3291
JacksonvilleFeb 1Jan 5330
ColumbusApr 20Oct 24185
CharlotteMar 30Nov 3221
IndianapolisApr 20Oct 21183
SeattleMar 13Nov 16248
DenverApr 30Oct 12165
Washington, DCMar 29Nov 8224
BostonApr 19Oct 23185
NashvilleApr 1Oct 31213
DetroitMay 1Oct 15166
Portland, ORMar 13Nov 22251
Las VegasJan 20Dec 15333
AtlantaMar 25Nov 9228
MinneapolisApr 29Oct 12163
Kansas City, MOApr 10Oct 27198
Salt Lake CityApr 29Oct 22174
St. LouisApr 1Nov 4218
RaleighMar 28Nov 8229
AlbuquerqueApr 6Nov 3208
AnchorageMay 28Sep 12107

"Rare" means a 32°F freeze happens there in fewer than 1 year in 10.

Questions people ask

What does "last frost date" mean?

It's the date after which a spring frost is as likely as not: half of years see their last 32°F night before it, half after. It's an average, not a promise, which is why the result also shows how late a frost comes 1 year in 10.

When is it safe to plant tomatoes?

NDSU suggests setting tomatoes out about 2 weeks after the average last frost, once nights stay warm. If you plan around the safer date instead, a late frost is unlikely.

Why is my date different from another site's?

Many sites use older 1981-2010 normals or a station further away. These are NOAA's newest normals, 1991-2020, from the station nearest where your county's people live.