Climate and average weather in Lake Ronkonkoma

In Lake Ronkonkoma, 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 Lake Ronkonkoma typically varies from 30°F to 77°F, and is rarely below 15°F or above 83°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 Lake Ronkonkoma for warm-weather activities is from late May to mid October.

Hottest
Jul
77°
Coldest
Jan
30°
Wettest
Dec
4.8 in
Driest
Jul
3.3 in
Rain / yr
46.8 in
118 wet days
Daylight
9.1–14.9 h
shortest–longest
Elevation
72 ft
40.8°N
Clearest
Oct
52% cloud

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

Density
1,575/km²
people per km²

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

Lake Ronkonkoma 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 Lake Ronkonkoma, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 3.7 months, from June 6 to September 27, with daily high temperatures above 68°F. The hottest month of the year in Lake Ronkonkoma is July, with an average high of 77°F and low of 71°F.

The cool season lasts 3.5 months, from December 10 to March 24, with daily high temperatures below 46°F. The coldest month of the year in Lake Ronkonkoma is January, with an average low of 30°F and high of 39°F.

Days typically run about 8°F warmer than nights year-round.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan3930
Feb3930
Mar4435
Apr5344
May6154
Jun7164
Jul7771
Aug7770
Sep7164
Oct6255
Nov5344
Dec4436

How hot and cold Lake Ronkonkoma 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 18°F (around January 23), with roughly 116 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)
Jan39392030
Feb39392030
Mar44442735
Apr52533944
May61615354
Jun71716464
Jul77777171
Aug77777070
Sep71716464
Oct62625455
Nov53533844
Dec45442836

Average hourly temperature in Lake Ronkonkoma

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 77°F, and coldest before dawn in January, near 30°F.

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

Lake Ronkonkoma 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
Jan39° / 30°3.89.949.40.0
Feb39° / 30°3.59.33.710.40.0
Mar44° / 35°4.610.62.911.70.8
Apr53° / 44°3.810.90.413.12.8
May61° / 54°3.510.8014.25.0
Jun71° / 64°3.69.9014.96.6
Jul77° / 71°3.39.4014.67.0
Aug77° / 70°3.99.5013.67.1
Sep71° / 64°3.89.1012.36.9
Oct62° / 55°4.49.2010.95.5
Nov53° / 44°3.78.90.39.73.0
Dec44° / 36°4.810.62.39.10.9

Chance of rain

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

Lake Ronkonkoma gets about 46.8 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 4.1 months, from around Feb 11 to Jun 16, peaking in April at about 37% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 30.

December is the wettest month by volume, with 4.8 in over about 11 wet days; July is the driest, with 3.3 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetApr 2 · 37%Aug 30 · 26%
Rain on a day (%)Rain days
Jan3210
Feb339
Mar3411
Apr3711
May3511
Jun3310
Jul309
Aug3110
Sep299
Oct309
Nov309
Dec3411

Monthly rainfall

Over a full year, Lake Ronkonkoma collects about 46.8 in of rain across 118 wet days — roughly 3.9 in in an average month.

It doesn’t fall evenly. December is the wettest month with 4.8 in, while July is the driest at just 3.3 in. The three wettest months alone bring about 30% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec3.83.54.63.83.53.63.33.93.84.43.74.8
Rainfall (in)Rain daysSnow days
Jan3.8104
Feb3.594
Mar4.6113
Apr3.8110
May3.5110
Jun3.6100
Jul3.390
Aug3.9100
Sep3.890
Oct4.490
Nov3.790
Dec4.8112

Snow in Lake Ronkonkoma

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.

Lake Ronkonkoma averages about 14 snowy days a year. Snow season runs roughly Nov 23 to Apr 12 — about 4.6 months.

February is snowiest, with roughly 4 days of snow and an estimated 12 in of snowfall. Over the year that adds up to an estimated 36 in of snow.

0246JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonFeb 8
Snow daysSnowfall (in)
Jan49
Feb412
Mar38
Apr01
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov01
Dec25

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Lake Ronkonkoma, 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 26 and lasts for 4.8 months, ending around November 19. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 56% of the time on average.

The cloudier part of the year begins around November 20 and lasts for 7.2 months, ending around June 25. The cloudiest month is May, 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 28 · 58%Apr 1 · 43%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan4852
Feb4753
Mar4555
Apr4456
May4456
Jun4753
Jul5545
Aug5644
Sep5545
Oct5545
Nov5050
Dec4654

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)
Jan9.47:214:43
Feb10.46:565:18
Mar11.76:125:52
Apr13.15:206:25
May14.24:416:57
Jun14.94:257:20
Jul14.64:387:18
Aug13.65:076:46
Sep12.35:395:55
Oct10.96:115:04
Nov9.76:474:28
Dec9.17:164:21

Sunny days

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

Lake Ronkonkoma averages about 10 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 Jul 3 to Nov 24. The sunniest month is October, with roughly 12 sunny days (mixed).

The greyest month is June, down near 9 sunny days — about 26% fewer than the October peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightOct 513 daysJun 69 days
Sunny daysSky
Jan10Mixed
Feb9Mixed
Mar9Mixed
Apr9Mixed
May9Mixed
Jun9Mixed
Jul11Mixed
Aug12Mixed
Sep13Mixed
Oct13Mixed
Nov11Mixed
Dec10Mixed

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 Lake Ronkonkoma, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.1 months, from around June 1 to October 3. 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 4 to May 31, 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 14 · 100%Jul 23 · 11%oppressivemuggyhumiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan10000000
Feb10000000
Mar10000000
Apr9910000
May76177100
Jun2026322020
Jul2102338251
Aug4142335251
Sep2721242360
Oct71179400
Nov9551000
Dec10000000

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 Lake Ronkonkoma is typically light breeze, near 11 mph, and varies moderately with the seasons.

The windier part of the year lasts 6.4 months, from around Oct 6 to Apr 19. The windiest month is January, averaging about 13 mph (breezy).

The calmer part of the year runs from around Apr 20 to Oct 5, with August the calmest month at about 9 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyJan 1 · 13 mphAug 7 · 8 mph
Wind speed (mph)Feels
Jan13breezy
Feb12light breeze
Mar12light breeze
Apr11light breeze
May10light breeze
Jun9light breeze
Jul9light breeze
Aug9light breeze
Sep10light breeze
Oct11light breeze
Nov12light breeze
Dec13breezy

Hazard calendar for Lake Ronkonkoma

In seasonPeak

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

Lake Ronkonkoma 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 Lake Ronkonkoma

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around early June, Lake Ronkonkoma is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

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 Lake Ronkonkoma 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
Jan0.0poor
Feb0.0poor
Mar0.8poor
Apr2.8poor
May5.0fair
Jun6.6good
Jul7.0good
Aug7.0good
Sep6.9good
Oct5.5fair
Nov3.0poor
Dec0.9poor

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 Lake Ronkonkoma 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 16 · 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 Lake Ronkonkoma, 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 77°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 39°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, Lake Ronkonkoma sees daytime highs around 77°F and nights near 71°F. Pack sun protection. Worth having: light clothes and rain gear. About 9 days see rain.

Sea temperature near Lake Ronkonkoma

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 14 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 3 to Sep 23 — about 2.7 months when the water holds above 68°F.

40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan43Bracing
Feb40Bracing
Mar40Bracing
Apr45Bracing
May54Bracing
Jun64Cool
Jul72Refreshing
Aug73Refreshing
Sep70Refreshing
Oct63Cool
Nov55Bracing
Dec49Bracing

UV index (midday) in Lake Ronkonkoma 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 Lake Ronkonkoma 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 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery 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 Lake Ronkonkoma

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
Feb00
Mar4.50
Apr60
May7.54
Jun84
Jul84.5
Aug6.51.5
Sep60
Oct20
Nov00
Dec00

Air quality in Lake Ronkonkoma 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 Lake Ronkonkoma is worst in July — around 19 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1018 µg/m³Nov 169 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar15Moderate
Apr16Moderate
May18Moderate
Jun18Moderate
Jul19Moderate
Aug16Moderate
Sep13Moderate
Oct10Good
Nov9Good
Dec10Good
Almanac & agriculture

Growing season

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

The growing season in Lake Ronkonkoma typically lasts about 310 days, from around March 1 to January 4 — the span where a frost-free day is more likely than not. It is reliably frost-free from March 29 to November 28.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 150%Mar 2990%Nov 2890%Jan 450%
Frost-free chance (%)Frost nights
Jan4131
Feb4028
Mar7128
Apr990
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov962
Dec7231

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. Lake Ronkonkoma banks about 3,058 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
Apr14
May234
Jun526
Jul747
Aug729
Sep537
Oct257
Nov15
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.

Lake Ronkonkoma receives about 4.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.7 and 6.6 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Mar 17 to Sep 20. The brightest month is July, averaging about 6.3 kWh/m² (intense).

The dimmest month is December, down near 1.8 kWh/m² — roughly 72% less than the July peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 26.6 kWhDec 171.7 kWh
Solar energy (kWh/m²)Level
Jan2.1Moderate
Feb3.0Moderate
Mar4.1Bright
Apr5.3Bright
May5.9Bright
Jun6.4Intense
Jul6.3Intense
Aug5.6Bright
Sep4.4Bright
Oct3.2Moderate
Nov2.3Moderate
Dec1.8Dim

Where is Lake Ronkonkoma?

Lake Ronkonkoma sits at 40.8°N, 73.1°W, 72 ft above sea level, in United States. The nearest listed city is Ronkonkoma, 1.2 mi away.

Topography around Lake Ronkonkoma

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

Within 2 miles, the terrain around Lake Ronkonkoma has only modest variations in elevation — a maximum elevation change of 194 ft around an average of 108 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 338 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,266 ft.

The land around Lake Ronkonkoma is covered by trees (71%) within 2 miles, trees (57%) within 10 miles, and water (51%) and trees (36%) within 50 miles.

2 miles
194 ft
10 miles
338 ft
50 miles
1,266 ft
treesgrasslandartificial surfaceswaterwetland
Nearby: Ronkonkoma 1.2 mi · Centereach 2.5 mi · Holbrook 3.1 mi · Hauppauge 3.7 mi · Smithtown 3.7 mi · Holtsville 5.0 mi · Central Islip 5.0 mi · Farmingville 5.6 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 Lake Ronkonkoma (40.8351°, -73.1312°, elevation 72 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).