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When does it first snow in Casper, WY?

At Casper, the typical date of the first measurable snowfall (0.1 inch or more in a day) is Oct 5. That is the median over the last 30 snow seasons: half of seasons saw it earlier, half later. In about 1 season in 10 it came by Sep 19, and in 1 in 10 not until Nov 11 or later. The earliest was Sep 7 (2020-21) and the latest Dec 30 (2024-25). A first snowfall of at least 1 inch in a single day typically arrives around Oct 9, and 100% of seasons had one. The first freeze of fall (a low of 32°F or colder) typically comes around Sep 20, and the last freeze of spring around May 25.

This season so far (2026-27, data through Oct 16, 2026): no measurable snow recorded yet; first freeze (32°F or colder) Oct 15 at this station. Compare with the typical dates above. This is observed data and can lag by a day or two, and it is not a forecast.

Oct 5Median first measurable snow (0.1"+)

Oct 9Median first 1"+ snowfall

73.2"Average snowfall per season

Sep 20Median first fall freeze (≤32°F)

May 25Median last spring freeze (≤32°F)

119Median freeze-free days between

First snowfall dates at Casper

First day with…	Median date	Typical range (10th–90th pct)	Earliest in 30 seasons	Latest in 30 seasons	Seasons with one
0.1" of snow or more (measurable)	Oct 5	Sep 19 – Nov 11	Sep 7 (2020-21)	Dec 30 (2024-25)	100%
1" of snow or more	Oct 9	Sep 19 – Nov 11	Sep 7 (2020-21)	Dec 30 (2024-25)	100%
3" of snow or more	Oct 29	Sep 25 – Dec 12	Sep 8 (2020-21)	Mar 13 (2001-02)	100%

Based on 28 seasons (July–June, 1995-96 to 2024-25) with at least 85% complete daily snowfall records at the station. Dates are for a single day’s snowfall, so "1 inch" means one calendar day with 1" or more, not total accumulation.

Chance the first snow has already happened by a given date

Snowfall	By Nov 1	By Dec 1	By Jan 1
0.1"+ (measurable)	86%	96%	100%
1"+	82%	96%	100%

In spring, the last measurable snowfall of the season typically falls around May 6 (median).

First and last freeze dates in Casper

Threshold	Event	Median date	Typical range (10th–90th pct)	Earliest / latest	Years with one
32°F or colder (freeze)	First in fall	Sep 20	Sep 7 – Oct 4	Aug 23 (2015) / Oct 6 (2023)	100%
32°F or colder (freeze)	Last in spring	May 25	May 14 – Jun 4	–	100%
28°F or colder (hard freeze)	First in fall	Oct 4	Sep 13 – Oct 13	Sep 7 (2010) / Oct 25 (2023)	100%
28°F or colder (hard freeze)	Last in spring	May 12	May 1 – May 23	–	100%

Based on the station’s daily minimum temperature, 1995–2024. “Freeze” here means a daily low at or below the threshold, which is not the same as visible frost. Your yard can differ by several degrees and days from an airport weather station, so use these as planning odds, not guarantees.

The median stretch between the last spring freeze and the first fall freeze (the freeze-free season) was about 119 days.

Nearby weather stations

Source station: Casper-Natrona Co Ap (USW00024089), elevation 5,319 ft. Data: NOAA NCEI GHCN-Daily. Computed by First Snow Dates; how we calculate this. Historical averages only; for a forecast see weather.gov.

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