How long is your growing season?
Your growing season is the stretch of days between the last frost of spring and the first frost of fall. Knowing its length tells you which crops will have time to ripen, and when you'll need help to stretch it.
How the season is measured
NOAA publishes growing-season lengths alongside its frost dates. For each station, it takes the longest run of days each year with no night at or below 32°F, across its 10,000 simulated years built from the 1991 to 2020 record, and reports how often the season reaches each length.
On every page here you'll see two numbers. The typical season is the length half of years beat. The short year is the length that 9 years in 10 reach: only 1 year in 10 is shorter. For crops that need every day they can get, the short-year figure is the one to plan around.
How long seasons run
Across the 206 places with their own page here that get a frost every year, the middle season is 202 days. These are the five shortest and the five longest:
| Place | Typical season | Short year (1 in 10) | Typical frost-free stretch |
|---|---|---|---|
| Bend, OR | 105 days | 81 days | June 6 to September 20 |
| Idaho Falls, ID | 114 days | 88 days | May 23 to September 20 |
| Casper, WY | 117 days | 96 days | May 26 to September 22 |
| Barre, VT | 119 days | 99 days | May 25 to September 22 |
| Fairbanks, AK | 121 days | 102 days | May 13 to September 13 |
| Gainesville, FL | 277 days | 246 days | March 3 to December 2 |
| College Station, TX | 278 days | 247 days | February 27 to November 30 |
| Augusta, GA | 283 days | 255 days | February 27 to December 4 |
| Gulfport, MS | 287 days | 255 days | February 23 to December 3 |
| Mobile, AL | 292 days | 257 days | February 21 to December 6 |
In the warmest places, many years have no freeze at all, so the "season" runs all year and frost stops being the thing that limits the garden.
Will a crop fit?
Seed packets list "days to harvest" (or "days to maturity"). Colorado State University Extension's planting guide gives typical figures for common vegetables:
- Radishes about 30 days, spinach 40, turnips and kohlrabi 50.
- Cucumbers 55; snap beans, leaf lettuce, beets and Swiss chard 60; peas 65; carrots 70.
- Sweet corn 60 to 90, depending on the variety.
- Cantaloupe and watermelon 85; winter squash 100; dry onions 110; leeks 120; potatoes 125.
- For transplants, the days count from the day you set them out: broccoli 65, tomatoes 65, peppers 70, cabbage 85.
Compare those with your season, remembering two things.
Frost-free isn't the same as warm. The very tender crops, such as melons, tomatoes, peppers and squash, need daytime temperatures above 60°F, and Colorado State warns that a week of days below 55°F can stunt them. That's one reason the planting rules here wait 2 weeks or more after the typical last frost to plant them out.
Growth slows in fall. Virginia Cooperative Extension adds about two weeks to fall plantings for the slower growth of shorter, cooler days. A crop that takes 90 days in summer can take longer if it's still ripening in September.
A rough check: a long crop such as winter squash or a late tomato fits comfortably if its days to harvest, plus a few weeks of margin, sit inside your short-year season. If it only fits your typical season, choose a faster variety, start it indoors, or plan to protect it.
Stretching the season
A few degrees of protection at each end can add weeks. Colorado State University Extension's trials in Fort Collins found that a clear plastic cover on a low frame typically gave 3°F to over 6°F of frost protection and added two to six weeks or more at both ends of the season for cool-season crops. Floating row cover, water-filled plant protectors and cold frames all help too; our guide to protecting plants from frost compares them.
The other way to stretch the season is to fill both ends with crops that like the cold. Peas, spinach and lettuce go in weeks before the last frost, and a second sowing in late summer carries the garden past the first one. See fall planting.
Find your season
Look up your ZIP code for your typical and short-year season, or browse frost dates by state.
Sources
- Readme: By-Variable and By-Station Normals Files, NOAA National Centers for Environmental Information. Checked October 25, 2026.
- Normals Calculation Methodology 2020, NOAA National Centers for Environmental Information. Checked October 25, 2026.
- Vegetable Planting Guide (CMG GardenNotes #720), Colorado State University Extension. Checked October 25, 2026.
- Frost Protection and Extending the Growing Season (CMG GardenNotes #722), Colorado State University Extension. Checked October 25, 2026.
- Fall Vegetable Gardening (426-334), Virginia Cooperative Extension, Virginia Tech. Checked October 25, 2026.
More guides: What your last frost date really means · Hardiness zones, and what changed on the 2023 map · How to protect plants from a late frost · Starting seeds indoors: when and how