Newcastle, WY 82701 Frost Dates
When can you plant in Newcastle, WY?
The last spring frost here typically falls around 05/13, about 258 days from today. The first fall frost typically arrives around 10/03, about 143 frost-free days later.
Newcastle sits in USDA Zone 4b (-25 to -20°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
About 5 weeks of growing season left in Newcastle before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Newcastle's last frost
05/13 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 05/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Newcastle compares
At roughly 143 frost-free days, Newcastle places 36,524 of 40,283 ZIP codes in this dataset. Within WY, it ranks 14 of 192.
Learn more
local microclimates covers what one yard in Newcastle can differ from the 82701 normal. zone vs. frost date covers why Zone 4b and Newcastle's frost date answer different questions.