Frost doesn’t care about the calendar. This page shows your cover-watch season — the weeks when a surprise frost is most plausible for your area — plus a nightly checklist you can actually use. One honest note up front: we can’t text you or send push alerts (yet). Email frost alerts are on the roadmap. Until then, this page plus your weather app is the whole system.
Enter your ZIP to see your cover-watch season.
- Check the forecast low. Not the “feels like” — the actual overnight low. If it’s near your crops’ danger zone, you have a job to do.
- Water the soil in the afternoon. Moist soil releases heat all night; dry soil gives up early.
- Cover before sunset. Covers trap the day’s warmth — putting them on after dark is almost pointless.
- Uncover after the frost melts. Plants need light and air; a sheet left on at noon cooks and smothers them.
Outside your watch season, a frost is unlikely — but weather surprises happen. If your forecast shows a low under 36°F any night of the year, run the checklist.
How it’s figured
Your cover-watch season runs from 30 days before your average first fall frost through 30 days after your average last spring frost — the shoulders of the season where a frost is plausible but nobody’s expecting it. Dates are long-term averages from published frost-date tables (Old Farmer’s Almanac and Extension sources). For a ZIP we show the nearest of 85 reporting cities and the distance to it; that’s station data, not a measurement at your exact address, and microclimates or elevation can shift real dates. ZIP locations come from the US Census 2024 Gazetteer.