Oswego, KS 67356 Frost Dates
Oswego, KS: when does the frost end?
Around 04/11 is the usual last spring frost, about 226 days away. Fall's first freeze usually shows up around 10/26, roughly 196 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Oswego in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 8 weeks until Oswego's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Oswego's last frost
04/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/26 and only about 1 year in 10 sees frost after that.
Oswego against the rest of the dataset
Oswego's growing season runs about 196 days, ranking 19,009 of 40,283 US ZIP codes measured here, longest to shortest. Within KS, it ranks 210 of 745.
Learn more
Before leaning on 67356's figures: local microclimates explains what one yard in Oswego can differ from the 67356 normal, while zone vs. frost date explains why Zone 7a and Oswego's frost date answer different questions.