Rugby, ND 58368 Frost Dates
58368, near Rugby, ND: the frost window
Typically, the last spring freeze lands around 05/17, roughly 262 days out. Fall's first freeze usually shows up around 09/23, roughly 129 days after the last spring frost.
Rugby sits in USDA Zone 3b (-35 to -30°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.
Stretching the season past the first frost
Rugby's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Rugby against the rest of the dataset
Rugby's growing season runs about 129 days, ranking 38,463 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 310 of 405.
Learn more
Two guides worth reading on 58368: the frost range, on how to read the range around Rugby's dates instead of trusting one, and local microclimates, on what one yard in Rugby can differ from the 58368 normal.