Last & First Frost Dates by ZIP Code

How to read your frost dates

A frost date is a probability, not a promise. NOAA looked at every night from 1991 to 2020 and worked out how likely a 32°F night is after each day in spring and before each day in fall.

• Average last frost (the median, or 50% date): in half of years the last frost of spring comes before this date, and in the other half it comes after.
• Safer planting date (10%): only 1 year in 10 has a frost after this date. Across all NOAA stations, it falls a median of 16 days after the average date.
• Average first frost (50%): the fall date with even odds that frost has arrived.
• Frost-free season: the days between the two average dates, roughly the season for tender crops.

Worked example: Plano, Texas

ZIP 75024 has no NOAA temperature station of its own. The nearest one is Richardson, 6.5 miles away.

• Average last spring frost: March 7. Planting tomatoes that day is a coin flip.
• Safer planting date: March 29, with a 1 in 10 chance of a later frost.
• Average first fall frost: November 21, but 1 year in 10 it arrives by November 2.
• Frost-free season: about 259 days.

Frost dates for major US cities

Each city uses the ZIP code at its center and that ZIP's nearest NOAA station, the same way the lookup above works. Your neighborhood can differ by a week or more.

Planting around your frost dates

• Cool-season crops (peas, spinach, lettuce, broccoli, cabbage) handle a light frost. Most go in the ground a few weeks before the average last frost.
• Warm-season crops (tomatoes, peppers, squash, beans, basil) die or stall in frost and cold soil. Extension guides set most of them out 1 to 2 weeks after the average last frost. In a cold spring, or if you'd rather not gamble, wait for the safer date.
• Count backward for seeds started indoors. A seed packet that says "start 6 to 8 weeks before last frost" means 6 to 8 weeks before the date above.

Planning a fall garden

For a fall crop, count back from the average first fall frost. The calendar in the lookup uses Montana State University Extension's schedule, which gives the latest planting time for each crop in weeks before the first frost. Virginia and Nebraska Extension explain why fall needs extra time: plants grow more slowly as days shorten and nights cool, which adds about two weeks (their "fall factor") to the days on the seed packet.

• In Plano the average first frost is November 21. Broccoli transplants go in by about August 15, and spinach by about October 10.
• Kale, collards, cabbage and spinach take a hard frost. Lettuce, chard and beets handle a light frost. Beans die at the first frost.
• The lookup above lists a fall planting date for 14 crops once you enter your ZIP code.

Why your yard may differ

Frost settles in low spots on clear, calm nights, so a valley floor can freeze while the slope just uphill stays clear. Cities hold heat, and big lakes and the ocean lengthen the frost-free season. Station thermometers sit about 5 feet above the ground, and plants near the ground can get frost while the station still reads a degree or two above 32°F.

Keep an eye on the 10-day forecast in spring. When a frost is forecast after you've planted, an old bedsheet or frost cloth over tender plants overnight usually saves them.

Where these numbers come from

The dates are NOAA's official 1991–2020 U.S. Climate Normals, which include frost dates for 7,305 stations. We match each ZIP code to the closest station by straight-line distance from the ZIP's center and show NOAA's dates unchanged. Frost-free days are the gap between NOAA's two median dates. Half of all ZIP codes have a station within about 7 miles. Where frost happens in fewer than 1 year in 10, or in every month, NOAA gives no dates and we say so. Where it happens only in some years, the dates describe those years only. Sources are listed on our how we calculate page.

Frequently asked questions

Last reviewed 2026-10-23. See how we calculate for our sources and assumptions.