Holtsville has chilly, snowy winters and pleasant summers
A typical July afternoon reaches 83°, a January night drops to 23°, and about 32 inches of snow falls in a normal winter.
A year in Holtsville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Holtsville’s climate
Read from where Holtsville sits among New York’s towns. The page puts what stands out first.
Warmer than it used to be
The last 30 years in Holtsville 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
Living with Holtsville’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
207 frost-free days. The last frost comes by Apr 10 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 2.
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 8 days a year reach 90°, and July afternoons average 83°.
The nicest months are May, June, July, August, September and October. 3.0 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 →What a year in Holtsville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
32 inches of snow, 46 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 207 frost-free days a year
In half of years the last 32° night comes by April 10 and the first by November 2.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
Holtsville and its neighbors
Farmingville has the coldest January nights next door (23°) and Centereach 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 Holtsville compares
Against every U.S. town on TownTapestry, each counted once, with its place in New York.
Holtsville 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 | 39° | 23° | 3.5" | 10.3" | 11 | 7 | 23° – 38° |
| February | 41° | 24° | 3.2" | 9.4" | 10 | 9 | 21° – 39° |
| March | 49° | 31° | 4.5" | 6.5" | 11 | 4 | 35° – 47° |
| April | 59° | 39° | 4.1" | 0.6" | 11 | 0 | 45° – 53° |
| May | 69° | 49° | 3.5" | 0 | 12 | 0 | 54° – 63° |
| June | 78° | 59° | 4.0" | 0 | 10 | 0 | 65° – 72° |
| July | 83° | 65° | 3.3" | 0 | 9 | 0 | 70° – 78° |
| August | 82° | 64° | 3.8" | 0 | 9 | 0 | 69° – 76° |
| September | 75° | 57° | 3.8" | 0 | 9 | 0 | 64° – 70° |
| October | 65° | 46° | 4.3" | 0 | 9 | 0 | 51° – 61° |
| November | 54° | 36° | 3.6" | 0.5" | 10 | 0 | 40° – 49° |
| December | 45° | 29° | 4.6" | 4.5" | 12 | 3 | 30° – 48° |
| Year | 61° | 44° | 46.1" | 31.8" | 122 | 23 |
Heating and cooling a home in Holtsville
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 30° to 48°. June is the most reliable, staying within 7°.
Common questions about Holtsville’s climate
What is the coldest month in Holtsville?
January, with a typical high of 39° and a low of 23°.
What is the hottest month in Holtsville?
July, with a typical high of 83° and a low of 65°. About 8 days a year reach 90°.
How much snow does Holtsville get?
About 32 inches in a normal winter, most of it in January.
When is the first frost in Holtsville?
In half of years the first 32° night comes by November 2, and the last spring frost by April 10.
What is the rainiest month in Holtsville?
December, with 4.6 inches of rain and melted snow. The year totals 46 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Holtsville.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Holtsville itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Islip Li Macarthur Airport, NY (3 mi) away. 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.