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When does it first snow in Islip, NY?

At Islip, the typical date of the first measurable snowfall (0.1 inch or more in a day) is Dec 12. 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 Nov 12, and in 1 in 10 not until Jan 7 or later. The earliest was Oct 29 (2011-12) and the latest Jan 19 (2006-07). A first snowfall of at least 1 inch in a single day typically arrives around Dec 20, and 100% of seasons had one. The first freeze of fall (a low of 32°F or colder) typically comes around Nov 2, and the last freeze of spring around Apr 11.

This season so far (2026-27, data through Oct 16, 2026): no measurable snow recorded yet; no 32°F freeze recorded yet 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.

Dec 12Median first measurable snow (0.1"+)

Dec 20Median first 1"+ snowfall

32.1"Average snowfall per season

14%Chance of white Christmas (1"+ on ground Dec 25)

Nov 2Median first fall freeze (≤32°F)

Apr 11Median last spring freeze (≤32°F)

206Median freeze-free days between

First snowfall dates at Islip

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)	Dec 12	Nov 12 – Jan 7	Oct 29 (2011-12)	Jan 19 (2006-07)	100%
1" of snow or more	Dec 20	Nov 29 – Jan 20	Nov 7 (2012-13)	Feb 27 (2022-23)	100%
3" of snow or more	Dec 30	Dec 5 – Feb 10	Nov 15 (2018-19)	Mar 16 (2006-07)	90%

Based on 30 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)	3%	27%	87%
1"+	0%	13%	70%

In spring, the last measurable snowfall of the season typically falls around Mar 18 (median).

White Christmas odds in Islip

NOAA defines a white Christmas as at least 1 inch of snow on the ground on the morning of December 25. Using the last 30 years of daily snow-depth records (1995–2024) at this station, Islip had that in 14% of years, at least 3 inches in 7%, and at least 6 inches in 3%. The average depth on Dec 25 was 0.6 inches and the deepest was 11 inches. New snow was falling (0.1" or more) on Christmas Day itself in 3% of years. Based on 29 years with a recorded depth on Dec 25.

Chance of at least 1 inch of snow on the ground, by date

Share of the last 30 years with 1"+ snow depth within 3 days of each date. Snow cover is most likely around Feb 13 (39%). Red line: Dec 25.

First and last freeze dates in Islip

Threshold	Event	Median date	Typical range (10th–90th pct)	Earliest / latest	Years with one
32°F or colder (freeze)	First in fall	Nov 2	Oct 13 – Nov 10	Oct 9 (2001) / Nov 15 (2022)	100%
32°F or colder (freeze)	Last in spring	Apr 11	Mar 30 – Apr 21	–	100%
28°F or colder (hard freeze)	First in fall	Nov 13	Nov 6 – Nov 29	Nov 4 (1996) / Dec 3 (2006)	100%
28°F or colder (hard freeze)	Last in spring	Mar 28	Mar 20 – Apr 11	–	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 206 days.

Nearby weather stations

Source station: Islip-Li Macarthur Ap (USW00004781), elevation 83 ft. Data: NOAA NCEI GHCN-Daily. Computed by First Snow Dates; how we calculate this. Historical averages only; for a forecast see weather.gov.

Planning for winter? Heat pump vs gas furnace, propane and oil: heating cost in New York (on our sister site PlugVsPump, from EIA prices).