Climate and average weather in Mastic

In Mastic, the summers are humid, warm, showery, and partly cloudy and the winters are cold, breezy, snowy, and partly cloudy.

Best: late May to mid October

Over the course of the year, the temperature in Mastic typically varies from 31°F to 76°F, and is rarely below 16°F or above 82°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Mastic for warm-weather activities is from late May to mid October.

Hottest
Jul
76°
Coldest
Jan
31°
Wettest
Dec
4.6 in
Driest
Jul
3.0 in
Rain / yr
44.6 in
113 wet days
Daylight
9.1–14.9 h
shortest–longest
Elevation
30 ft
40.8°N
Clearest
Aug
50% cloud

Mastic is census-designated place in Suffolk County, New York, United States.

Density
1,481/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Mastic weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late May to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Mastic, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 3.6 months, from June 9 to September 27, with daily high temperatures above 68°F. The hottest month of the year in Mastic is July, with an average high of 76°F and low of 71°F.

The cool season lasts 3.5 months, from December 11 to March 26, with daily high temperatures below 46°F. The coldest month of the year in Mastic is January, with an average low of 31°F and high of 40°F.

Days typically run about 7°F warmer than nights year-round.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan4031
Feb4031
Mar4436
Apr5245
May6053
Jun7064
Jul7671
Aug7670
Sep7165
Oct6255
Nov5346
Dec4537

How hot and cold Mastic really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about 19°F (around January 22), with roughly 114 freezing days a year (feels-like at or below 32°F), worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan40402131
Feb40402131
Mar44442736
Apr52523845
May60605353
Jun70706464
Jul76767171
Aug76767070
Sep71716565
Oct62625555
Nov53533946
Dec45452937

Average hourly temperature in Mastic

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 76°F, and coldest before dawn in January, near 31°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Mastic weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan40° / 31°3.79.83.99.40.0
Feb40° / 31°3.49.13.510.40.0
Mar44° / 36°4.410.22.811.70.8
Apr52° / 45°3.610.30.413.12.7
May60° / 53°3.310.2014.24.8
Jun70° / 64°3.38.8014.96.7
Jul76° / 71°3.08.6014.67.2
Aug76° / 70°3.79.3013.67.2
Sep71° / 65°3.78.8012.36.9
Oct62° / 55°4.39010.95.5
Nov53° / 46°3.68.70.39.73.2
Dec45° / 37°4.610.62.29.11.1

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Mastic gets about 44.6 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 3.5 months, from around Feb 9 to May 27, peaking in April at about 36% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Sep 2.

December is the wettest month by volume, with 4.6 in over about 11 wet days; July is the driest, with 3.0 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetApr 2 · 36%Sep 2 · 25%
Rain on a day (%)Rain days
Jan3210
Feb329
Mar3310
Apr3410
May3310
Jun299
Jul289
Aug309
Sep289
Oct309
Nov309
Dec3411

Monthly rainfall

Over a full year, Mastic collects about 44.6 in of rain across 113 wet days — roughly 3.7 in in an average month.

It doesn’t fall evenly. December is the wettest month with 4.6 in, while July is the driest at just 3.0 in. The three wettest months alone bring about 30% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec3.73.44.43.63.33.33.03.73.74.33.64.6
Rainfall (in)Rain daysSnow days
Jan3.7104
Feb3.494
Mar4.4103
Apr3.6100
May3.3100
Jun3.390
Jul3.090
Aug3.790
Sep3.790
Oct4.390
Nov3.690
Dec4.6112

Snow in Mastic

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Mastic averages about 13 snowy days a year. Snow season runs roughly Nov 25 to Apr 13 — about 4.6 months.

February is snowiest, with roughly 4 days of snow and an estimated 11 in of snowfall. Over the year that adds up to an estimated 33 in of snow.

0246JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonFeb 3
Snow daysSnowfall (in)
Jan48
Feb411
Mar38
Apr01
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov00
Dec25

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Mastic, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around June 25 and lasts for 4.4 months, ending around November 4. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 59% of the time on average.

The cloudier part of the year begins around November 5 and lasts for 7.6 months, ending around June 24. The cloudiest month is December, when it is overcast or mostly cloudy 56% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecAug 31 · 61%Dec 15 · 41%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan4654
Feb4753
Mar4654
Apr4654
May4555
Jun4852
Jul5743
Aug5941
Sep5743
Oct5644
Nov4951
Dec4456

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 10, brings about 14 h 54 min of light; the shortest, around January 1, only 9 h 06 min — a swing of roughly 5 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.47:194:42
Feb10.46:555:17
Mar11.76:115:51
Apr13.15:196:24
May14.24:406:56
Jun14.94:247:19
Jul14.64:377:17
Aug13.65:066:45
Sep12.35:385:54
Oct10.96:105:03
Nov9.76:464:27
Dec9.17:154:20

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Mastic averages about 11 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 9 and 13 days.

The sunnier stretch runs 4.8 months, from around Jun 21 to Nov 12. The sunniest month is October, with roughly 12 sunny days (mixed).

The greyest month is December, down near 9 sunny days — about 27% fewer than the October peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightOct 313 daysDec 169 days
Sunny daysSky
Jan10Mixed
Feb9Mixed
Mar10Mixed
Apr10Mixed
May10Mixed
Jun10Mixed
Jul12Mixed
Aug13Mixed
Sep13Mixed
Oct13Mixed
Nov10Mixed
Dec9Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Mastic, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.1 months, from around June 3 to October 5. The muggiest month is July, when the air feels humid, muggy or worse about 88% of the time.

The most comfortable stretch runs from around October 6 to June 2, and April is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecApr 19 · 100%Jul 22 · 10%oppressivemuggyhumiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan1000000
Feb1000000
Mar1000000
Apr1000000
May7915510
Jun202732192
Jul210233926
Aug413233426
Sep272024246
Oct69171040
Nov945100
Dec1000000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Mastic is typically light breeze, near 12 mph, and varies moderately with the seasons.

The windier part of the year lasts 6.4 months, from around Oct 8 to Apr 19. The windiest month is December, averaging about 14 mph (breezy).

The calmer part of the year runs from around Apr 20 to Oct 7, with August the calmest month at about 9 mph.

05101520JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezywindyDec 23 · 14 mphAug 8 · 9 mph
Wind speed (mph)Feels
Jan14breezy
Feb14breezy
Mar13breezy
Apr12light breeze
May11light breeze
Jun10light breeze
Jul10light breeze
Aug9light breeze
Sep11light breeze
Oct12breezy
Nov13breezy
Dec14breezy

Hazard calendar for Mastic

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

Mastic sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Best time to visit Mastic

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Mastic throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around early October, Mastic is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best time of year to visit Mastic for general outdoor tourist activities is from late May to mid October, with a peak score in the last week of August.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationAug 29 · 7.4

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.1poor
Feb0.0poor
Mar0.8poor
Apr2.7poor
May4.8fair
Jun6.7good
Jul7.2good
Aug7.2good
Sep6.9good
Oct5.5good
Nov3.2poor
Dec1.1poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Mastic for hot-weather activities is from late June to mid September, with a peak score in the third week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 15 · 6.5

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Mastic, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 76°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 40°F), pack a warm layer, a heavy coat, rain gear and a windbreaker.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Mastic sees daytime highs around 76°F and nights near 71°F. Pack sun protection. Worth having: light clothes and rain gear. About 9 days see rain.

Sea temperature near Mastic

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea at the nearest coast (about 12 mi away) is warmest in August at about 73°F and coldest in February near 40°F.

It's comfortable for a long swim from Jul 4 to Sep 22 — about 2.7 months when the water holds above 68°F.

40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan44Bracing
Feb40Bracing
Mar41Bracing
Apr45Bracing
May53Bracing
Jun64Cool
Jul71Refreshing
Aug73Refreshing
Sep69Refreshing
Oct63Cool
Nov56Bracing
Dec49Bracing

UV index (midday) in Mastic by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Mastic peaks around July 11 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 11UV 8Dec 22UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Average hourly UV index in Mastic

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in July the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 4.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb0.50
Mar4.50
Apr60
May7.54
Jun84
Jul84.5
Aug6.51.5
Sep60
Oct20
Nov00
Dec00

Air quality in Mastic by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Mastic is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1016 µg/m³Nov 178 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar14Moderate
Apr15Moderate
May16Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep11Good
Oct9Good
Nov8Good
Dec8Good
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Mastic typically lasts about 320 days, from around February 24 to January 9 — the span where a frost-free day is more likely than not. It is reliably frost-free from March 27 to December 1.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonFeb 2450%Mar 2790%Dec 190%Jan 950%
Frost-free chance (%)Frost nights
Jan4631
Feb4428
Mar7426
Apr990
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov970
Dec7630

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Mastic banks about 2,990 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr9
May210
Jun500
Jul730
Aug719
Sep532
Oct267
Nov22
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Mastic receives about 4.3 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.7 and 6.7 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Mar 18 to Sep 21. The brightest month is July, averaging about 6.5 kWh/m² (intense).

The dimmest month is December, down near 1.8 kWh/m² — roughly 73% less than the July peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 26.7 kWhDec 181.7 kWh
Solar energy (kWh/m²)Level
Jan2.1Moderate
Feb3.0Moderate
Mar4.2Bright
Apr5.4Bright
May6.0Intense
Jun6.5Intense
Jul6.5Intense
Aug5.8Bright
Sep4.5Bright
Oct3.3Moderate
Nov2.2Moderate
Dec1.7Dim

Where is Mastic?

Mastic sits at 40.8°N, 72.8°W, 30 ft above sea level, in United States. The nearest listed city is Shirley, 1.2 mi away.

Topography around Mastic

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Mastic.

Within 2 miles, the terrain around Mastic has only modest variations in elevation — a maximum elevation change of 98 ft around an average of 46 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 328 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 965 ft.

The land around Mastic is covered by trees (63%) within 2 miles, trees (46%) and water (36%) within 10 miles, and water (59%) and trees (32%) within 50 miles.

2 miles
98 ft
10 miles
328 ft
50 miles
965 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
Nearby: Shirley 1.2 mi · Medford 8.7 mi · East Patchogue 8.7 mi · Coram 9.3 mi · Farmingville 9.9 mi · Holtsville 11 mi · Selden 11 mi · Holbrook 12 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Mastic (40.802°, -72.8409°, elevation 30 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).