Cold Spring Harbor, New York Weather
Fireflies rise from the lawn. Day 78 of spring. Read this microseason across nine climate regions →
Cold Spring Harbor weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Partly Cloudy——87°56°—
- FridayJun 5Overcast——91°61°+4°
- SaturdayJun 6Drizzle44%0.02″93°64°+2°
- SundayJun 7Heavy Showers44%0.83″81°66°-12°
- MondayJun 8Partly Cloudy——79°59°-2°
- TuesdayJun 9Overcast——84°64°+5°
- WednesdayJun 10Mostly Clear——87°68°+3°
AQI 91 (Moderate), driven by PM2.5. AQI up 28 in the last 6 hours — air quality is degrading. PM2.5 at 17.9 µg/m³, PM10 at 21.7 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 36 now. With UV 0.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 6 by mid-afternoon.
- Present
- AQI 36
- UV peak
- 0.0 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 6
PM × Wind × Precip
PM2.5 at 17.9 µg/m³, PM10 at 21.7 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.82
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
The higher the clouds, the finer the weather.
- Moonrise
- 3:55 AM
- Moonset
- 1:56 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Cold Spring Harbor at a glance
- Today vs. normal: 6°F below the seasonal normal for this latitude
- Last frost: April 21 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Cold Spring Harbor
SPC has placed Cold Spring Harbor in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Cold Spring Harbor's warmest month is July (~75°F mean) and its coldest is January (~32°F). Rainfall peaks in September (3.7 inches) and bottoms out in February (2.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 32° | 2.7″ | 5 |
| February | 34° | 2.0″ | 5 |
| March | 40° | 3.5″ | 6 |
| April | 50° | 3.6″ | 6 |
| May | 60° | 3.2″ | 7 |
| June | 69° | 3.5″ | 7 |
| July | 75° | 3.0″ | 5 |
| August | 74° | 3.3″ | 6 |
| September | 67° | 3.7″ | 5 |
| October | 56° | 3.4″ | 5 |
| November | 46° | 2.9″ | 6 |
| December | 38° | 3.6″ | 7 |
Regional context
Cold Spring Harbor's baseline climate, derived from NOAA NCEI 1991-2020 normals at the nearest reporting station, swings from a January mean of 32°F to a July mean of 75°F — a 43°F seasonal arc typical of the mid-latitude bands. Annual precipitation runs about 38.3 inches spread across roughly 69 days with measurable rain or snow each year.
Rainfall stays relatively even across the calendar: September tops out at 3.7 inches across 5.1 days with measurable rain, and February settles around 2.0 inches across 4.7 rainy days — a comparatively narrow seasonal range. The temperate, evenly-distributed pattern groups Cold Spring Harbor with places like Laurel Hollow, NY, Halesite, NY and Huntington Station, NY, where seasonal storm tracks deliver moisture more uniformly than the continental interior.
The frost-sensitive growing window opens around mid-April, when overnight lows reliably clear freezing for cool-season crops like peas, lettuce, spinach, and radishes. Warm-season transplants — tomatoes, peppers, and basil — typically wait two weeks past that date to avoid late spring cold snaps. The window closes around mid-November, when overnight lows resume dipping below freezing and frost-tender plants need protection or harvest. These dates represent 30-year central tendencies; actual year-to-year variation can shift either bookend by 7-14 days, and local microclimate features within Cold Spring Harbor — cold-air drainage on calm clear nights, slope aspect, distance from any nearby lake or river — can push the practical frost window earlier or later than the regional average.
Similar climates: Laurel Hollow, NY, Halesite, NY, Huntington Station, NY, Oyster Bay Cove, NY, Cove Neck, NY.
Frequently asked
- When does it freeze in Cold Spring Harbor?
- Cold Spring Harbor's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Cold Spring Harbor?
- September is the wettest month with about 3.7 inches of rain on average; the city receives roughly 38 inches annually.
- What is the warmest month in Cold Spring Harbor?
- July is typically warmest, averaging about 75°F.
- What is the coldest month in Cold Spring Harbor?
- January is typically coldest, averaging about 32°F.
- When can I start a vegetable garden in Cold Spring Harbor?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-April); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Cold Spring Harbor get?
- Cold Spring Harbor averages about 69 rainy days per year.
- What hardiness zone is Cold Spring Harbor?
- Cold Spring Harbor's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Cold Spring Harbor, New York sits in a warm-summer humid continental climate zone. January means hover near 32°F while July averages 75°F — a 43°F seasonal swing.
Across the year, Cold Spring Harbor receives about 38 inches of precipitation spread over roughly 69 rainy days.
The rhythm of the year is set by latitude (40.9°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.
Beaches near Cold Spring Harbor
- Jones Beach Beach18.7 mi
- Robert Moses Beach19.1 mi
- Long Beach NY Beach21.8 mi
Each linked page shows live water temperature, wave height, swim and surf verdicts, tides, and rip-current risk from NDBC + NOAA + NWS data.