Brentford, SD 57429 Frost Dates
Frost dates for Brentford, SD, ZIP 57429
The last spring frost here typically falls around 05/06, about 251 days from today. The first fall frost typically arrives around 09/29, about 144 frost-free days later.
Brentford sits in USDA Zone 4a (-30 to -25°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 4a around Brentford has about 5 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/06 is the middle of 30 years of NOAA records, not a promise. Plant by 04/25 and you're betting against frost in roughly 9 years out of 10. 05/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Brentford compares
Brentford's growing season runs about 144 days, ranking 36,477 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 263 of 378.
Learn more
the frost range explains how to read the range around Brentford's dates instead of trusting one, and local microclimates explains what one yard in Brentford can differ from the 57429 normal.