We look up the weather station closest to your place. Then we use NOAA’s 30-year record (1991–2020) to guess when frost usually ends in spring and starts in fall. Frost here means 32°F; a hard freeze is 28°F.
Safe means only about 1 year in 10 frost comes later in spring (or earlier in fall) than that date. Median is a coin flip. Bold is the risky end: about 9 years in 10 frost still comes after that date.
The next 7 nights come live from the National Weather Service. Go = above 40°F, Wait = 37–40°F, Cover = 36°F or colder, Freeze = 28°F or colder. ZIPs come from the Census. This isn’t a guarantee — check your own thermometer.
Frost dates: NOAA NCEI 1991–2020 · Nights: NWS · Not endorsed by NOAA