White Sulphur Springs, MT 59642 Frost Dates
59642, near White Sulphur Springs, MT: the frost window
The NOAA station nearest to 59642 does not report a usable frost-date normal for either event, so no last-frost or first-frost figure is shown here. The USDA hardiness zone below is still real: Zone 4b (-25 to -20°F average annual minimum).
White Sulphur Springs against the rest of the dataset
White Sulphur Springs's growing season runs about 65 days, ranking 40,152 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 376 of 392.
Learn more
Two guides worth reading on 59642: the methodology, on exactly which NOAA and USDA figures feed 59642's numbers, and zone vs. frost date, on why Zone 4b and White Sulphur Springs's frost date answer different questions.