West Islip has chilly, snowy winters and pleasant summers
A typical July afternoon reaches 84°, a January night drops to 25°, and about 32 inches of snow falls in a normal winter.
A year in West Islip at a glance
Each month’s typical high and low, and what it brings.
What stands out about West Islip’s climate
Read from where West Islip sits among New York’s towns. The page puts what stands out first.
Warmer than it used to be
The last 30 years in West Islip averaged 2.3° warmer than the 1900s. The biggest change is in December (+3.7°).
A bigger shift than in 99% of U.S. towns.
Change by month
What a year in West Islip feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Living with West Islip’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
213 frost-free days. The last frost comes by Apr 6 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 6.
About 32" a winter over 8 days with an inch or more, most in January. Snow covers the ground about 23 days a year.
Months averaging under 55° run from November through April. Heating is 85% of the year’s heating-and-cooling load.
About 9 days a year reach 90°, and July afternoons average 84°.
The nicest months are May, June, July, August, September and October. 0.1 miles of trails are waiting.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →32 inches of snow, 45 of rain and melt
December is the wettest month and February the driest. Rain or snow falls on about 122 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
About 213 frost-free days a year
In half of years the last 32° night comes by April 6 and the first by November 6.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
West Islip and its neighbors
Baywood has the coldest January nights next door (24°) and Babylon the hottest July afternoons (84°). Tap a town to see its climate.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
How West Islip compares
Against every U.S. town on TownTapestry, each counted once, with its place in New York.
West Islip weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 40° | 25° | 3.3" | 10.3" | 11 | 7 | 25° – 39° |
| February | 42° | 26° | 3.0" | 9.4" | 10 | 9 | 22° – 40° |
| March | 49° | 32° | 4.2" | 6.5" | 11 | 4 | 36° – 48° |
| April | 59° | 41° | 3.8" | 0.6" | 11 | 0 | 46° – 54° |
| May | 69° | 51° | 3.4" | 0 | 12 | 0 | 55° – 64° |
| June | 78° | 60° | 4.0" | 0 | 10 | 0 | 66° – 73° |
| July | 84° | 67° | 3.4" | 0 | 9 | 0 | 70° – 79° |
| August | 82° | 65° | 4.0" | 0 | 9 | 0 | 70° – 78° |
| September | 76° | 59° | 3.9" | 0 | 9 | 0 | 65° – 71° |
| October | 65° | 47° | 4.0" | 0 | 9 | 0 | 52° – 62° |
| November | 55° | 38° | 3.4" | 0.5" | 10 | 0 | 41° – 51° |
| December | 45° | 31° | 4.3" | 4.5" | 12 | 3 | 31° – 49° |
| Year | 62° | 45° | 44.6" | 31.8" | 122 | 23 |
Heating and cooling a home in West Islip
85% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 31° to 49°. September is the most reliable, staying within 7°.
Common questions about West Islip’s climate
What is the coldest month in West Islip?
January, with a typical high of 40° and a low of 25°.
What is the hottest month in West Islip?
July, with a typical high of 84° and a low of 67°. About 9 days a year reach 90°.
How much snow does West Islip get?
About 32 inches in a normal winter, most of it in January.
When is the first frost in West Islip?
In half of years the first 32° night comes by November 6, and the last spring frost by April 6.
What is the rainiest month in West Islip?
December, with 4.3 inches of rain and melted snow. The year totals 45 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in West Islip.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for West Islip itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Islip Li Macarthur Airport, NY (12 mi, snow) and Farmingdale Airport, NY (7 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000. Today’s forecast: National Weather Service.