Sinclair, WY 82334 Frost Dates
Sinclair, WY: when does the frost end?
The last spring frost here typically falls around 06/01, about 277 days from today. Fall's first freeze usually shows up around 09/15, roughly 105 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Sinclair in Zone 5a (-20 to -15°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 3 weeks until Sinclair's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 06/01 isn't a guarantee
06/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/17 and only about 1 year in 10 sees frost after that.
Sinclair against the rest of the dataset
Sinclair's growing season runs about 105 days, ranking 39,603 of 40,283 US ZIP codes measured here, longest to shortest. Within WY, it ranks 134 of 192.
Learn more
Before leaning on 82334's figures: local microclimates explains what one yard in Sinclair can differ from the 82334 normal, while zone vs. frost date explains why Zone 5a and Sinclair's frost date answer different questions.