Frost Advisory
Starts in 6 h 31 min
When
From midnight tonight to 9 AM EDT Sunday.
Where
In Connecticut, Southern Fairfield, Southern Middlesex, Southern New Haven, and Southern New London Counties. In New York, Northeast Suffolk and Southeast Suffolk Counties.
Issued for this forecast zone · National Weather Service Upton NY
What, impacts and precautionsHide details
What
Temperatures in the mid 30s, and locally as low 25 to 30 in parts of the Pine Barrens of Long Island, will result in frost formation.
Impacts
Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.
Precautionary actions
Take steps now to protect tender plants from the cold.
Areas: Southern Fairfield; Southern New Haven; Southern Middlesex; Southern New London; Northeast Suffolk; Southeast Suffolk
See it on weather.gov (opens in a new tab)

Observed 4:55 PM EDT at KHWV

Mastic Beach, NY weather

Sunny and 61°16°.

Mostly agree

Now 61°16°

Sunny

Wind: 3 mph5 km/h; From the west-northwest. Light through 5 AM
Dew point: 28°−2°; Dry · up to 37°3° by 6 PM (comfortable)
UV tomorrow: 4Moderate; Moderate 11 AM–4 PM · peak 4
Pressure: 30.51 inHg1033 hPa; Falling slowly · −0.03 inHg−0.9 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

Good hours for

Below 50°10° tonight after 8 PM
Low 38°3° tonight at 5 AM
Above 50°10° tomorrow by 10 AM

TonightDown to 38°3° by 5 AM · Clear
Tomorrow morningUp to 54°12° by 11 AM · Clear
Tomorrow afternoonUp to 62°17° by 4 PM · Clear
Tomorrow nightDown to 45°7° by 4 AM · Clear
Monday morningUp to 56°13° by 11 AM · Clear
Monday afternoonUp to 64°18° by 3 PM · Clear

Hourly forecast, next 48 hours, in the place's local time
Hour	Conditions	Temperature	Feels like	Precipitation	Wind	Humidity	Cloud cover	UV index
Sat 5p	Sunny	58°14° (likely 56°13° to 59°15°)	58°14°	0%	5 mph8 km/h from W, gusts 9 mph14 km/h	45%	43%	0
Sat 6p	Partly cloudy	55°13° (likely 52°11° to 56°13°)	55°13°	0%	3 mph5 km/h from W, gusts 8 mph13 km/h	51%	42%	0
Sat 7p	Mostly clear	52°11° (likely 49°9° to 54°12°)	52°11°	0%	3 mph5 km/h from W, gusts 8 mph13 km/h	59%	61%	0
Sat 8p	Mostly clear	48°9° (likely 47°8° to 53°12°)	48°9°	0%	2 mph3 km/h from W, gusts 8 mph13 km/h	68%	28%	0
Sat 9p	Clear	46°8° (likely 46°8° to 52°11°)	46°8°	0%	2 mph3 km/h from W, gusts 8 mph13 km/h	73%	11%	0
Sat 10p	Clear	45°7° (likely 45°7° to 51°11°)	45°7°	0%	2 mph3 km/h from NW, gusts 7 mph11 km/h	76%	8%	0
Sat 11p	Clear	44°7° (likely 44°7° to 50°10°)	44°7°	0%	2 mph3 km/h from NW, gusts 7 mph10 km/h	79%	1%	0
Sun 12a	Clear	44°7° (likely 43°6° to 49°9°)	44°7°	0%	2 mph3 km/h from NW, gusts 6 mph10 km/h	79%	0%	0
Sun 1a	Clear	43°6° (likely 43°6° to 48°9°)	41°5°	0%	3 mph5 km/h from NW, gusts 6 mph10 km/h	82%	0%	0
Sun 2a	Clear	41°5° (likely 41°5° to 48°9°)	39°4°	0%	3 mph5 km/h from NW, gusts 7 mph11 km/h	89%	1%	0
Sun 3a	Clear	40°4° (likely 40°4° to 47°8°)	38°3°	0%	3 mph5 km/h from NW, gusts 7 mph11 km/h	92%	1%	0
Sun 4a	Clear	39°4° (likely 39°4° to 46°8°)	37°3°	0%	3 mph5 km/h from NW, gusts 6 mph10 km/h	92%	1%	0
Sun 5a	Clear	38°3° (likely 38°3° to 46°8°)	36°2°	0%	3 mph5 km/h from NW, gusts 6 mph10 km/h	96%	2%	0
Sun 6a	Clear	39°4° (likely 39°4° to 46°8°)	37°3°	0%	3 mph5 km/h from NW, gusts 6 mph10 km/h	89%	2%	0
Sun 7a	Sunny	40°4° (likely 40°4° to 46°8°)	37°3°	0%	5 mph8 km/h from N, gusts 6 mph10 km/h	89%	2%	0
Sun 8a	Sunny	41°5° (likely 41°5° to 46°8°)	38°3°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	86%	2%	0
Sun 9a	Sunny	46°8° (likely 46°8° to 49°9°)	44°7°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	73%	0%	1
Sun 10a	Sunny	51°11° (likely 51°11° to 55°13°)	51°11°	0%	3 mph5 km/h from N, gusts 5 mph9 km/h	63%	0%	2
Sun 11a	Sunny	54°12° (likely 54°12° to 59°15°)	54°12°	0%	3 mph5 km/h from N, gusts 7 mph11 km/h	59%	0%	3
Sun 12p	Sunny	57°14° (likely 57°14° to 62°17°)	57°14°	0%	3 mph5 km/h from NW, gusts 8 mph12 km/h	53%	0%	4
Sun 1p	Sunny	59°15° (likely 59°15° to 64°18°)	59°15°	0%	3 mph5 km/h from W, gusts 7 mph11 km/h	49%	0%	4
Sun 2p	Sunny	61°16° (likely 60°16° to 64°18°)	61°16°	0%	3 mph5 km/h from SW, gusts 6 mph10 km/h	48%	0%	4
Sun 3p	Sunny	61°16° (likely 60°16° to 64°18°)	61°16°	0%	5 mph8 km/h from SW, gusts 7 mph11 km/h	48%	0%	3
Sun 4p	Sunny	62°17° (likely 60°16° to 63°17°)	62°17°	0%	5 mph8 km/h from SW, gusts 8 mph13 km/h	48%	0%	2
Sun 5p	Sunny	60°16° (likely 58°14° to 61°16°)	60°16°	0%	6 mph10 km/h from SW, gusts 8 mph12 km/h	53%	0%	1
Sun 6p	Clear	58°14° (likely 53°12° to 58°14°)	58°14°	0%	6 mph10 km/h from SW, gusts 8 mph13 km/h	57%	0%	0
Sun 7p	Clear	56°13° (likely 50°10° to 56°13°)	56°13°	0%	5 mph8 km/h from SW, gusts 8 mph13 km/h	64%	0%	0
Sun 8p	Clear	52°11° (likely 49°9° to 54°12°)	52°11°	0%	5 mph8 km/h from SW, gusts 8 mph13 km/h	74%	0%	0
Sun 9p	Clear	51°11° (likely 49°9° to 54°12°)	51°11°	0%	5 mph8 km/h from SW, gusts 9 mph14 km/h	77%	0%	0
Sun 10p	Clear	51°11° (likely 48°9° to 54°12°)	51°11°	0%	5 mph8 km/h from SW, gusts 10 mph15 km/h	80%	0%	0
Sun 11p	Clear	50°10° (likely 47°8° to 54°12°)	48°9°	0%	5 mph8 km/h from SW, gusts 10 mph17 km/h	83%	0%	0
Mon 12a	Clear	49°9° (likely 46°8° to 53°12°)	47°8°	0%	5 mph8 km/h from W, gusts 11 mph17 km/h	86%	0%	0
Mon 1a	Clear	49°9° (likely 45°7° to 53°12°)	47°8°	0%	6 mph10 km/h from W, gusts 12 mph20 km/h	86%	1%	0
Mon 2a	Clear	48°9° (likely 43°6° to 52°11°)	45°7°	0%	6 mph10 km/h from W, gusts 13 mph21 km/h	86%	0%	0
Mon 3a	Clear	46°8° (likely 43°6° to 51°11°)	43°6°	0%	6 mph10 km/h from W, gusts 13 mph20 km/h	89%	0%	0
Mon 4a	Clear	45°7° (likely 42°6° to 50°10°)	41°5°	0%	7 mph11 km/h from W, gusts 13 mph21 km/h	89%	0%	0
Mon 5a	Clear	45°7° (likely 41°5° to 50°10°)	41°5°	0%	7 mph11 km/h from W, gusts 14 mph22 km/h	89%	0%	0
Mon 6a	Clear	45°7° (likely 41°5° to 49°9°)	41°5°	0%	7 mph11 km/h from W, gusts 14 mph22 km/h	86%	0%	0
Mon 7a	Sunny	45°7° (likely 41°5° to 48°9°)	41°5°	0%	8 mph13 km/h from W, gusts 14 mph22 km/h	86%	0%	0
Mon 8a	Sunny	46°8° (likely 41°5° to 49°9°)	42°6°	0%	8 mph13 km/h from W, gusts 12 mph20 km/h	86%	9%	0
Mon 9a	Sunny	50°10° (likely 48°9° to 51°11°)	47°8°	0%	8 mph13 km/h from W, gusts 13 mph21 km/h	77%	14%	1
Mon 10a	Sunny	53°12° (likely 53°12° to 56°13°)	53°12°	0%	8 mph13 km/h from W, gusts 14 mph23 km/h	74%	11%	2
Mon 11a	Sunny	56°13° (likely 56°13° to 60°16°)	56°13°	0%	8 mph13 km/h from W, gusts 13 mph21 km/h	69%	9%	3
Mon 12p	Sunny	59°15° (likely 59°15° to 63°17°)	59°15°	0%	9 mph14 km/h from W, gusts 13 mph20 km/h	64%	3%	4
Mon 1p	Sunny	61°16° (likely 61°16° to 65°18°)	61°16°	0%	10 mph16 km/h from W, gusts 12 mph19 km/h	60%	2%	4
Mon 2p	Sunny	63°17° (likely 62°17° to 66°19°)	63°17°	0%	10 mph16 km/h from W, gusts 12 mph19 km/h	58%	0%	4
Mon 3p	Sunny	64°18° (likely 61°16° to 66°19°)	64°18°	0%	10 mph16 km/h from W, gusts 11 mph18 km/h	58%	2%	3
Mon 4p	Sunny	64°18° (likely 62°17° to 66°19°)	64°18°	0%	9 mph14 km/h from W, gusts 11 mph18 km/h	58%	0%	2

Days ahead

Shaded: typical range for these dates (1991–2020)

Today, Oct 24. Cloudy. High 59°15°, low 38°3°. Typical 61°16° / 44°7°. Dry. Mostly agree.
1. Evening
  6 PM–midnight
  Clear, 48°9°
  Dry
2. Overnight
  midnight–6 AM
  Clear, 38°3°
  Dry
Official NWS forecast
Today: Mostly sunny, with a high near 59. West wind around 5 mph.
Tonight: Patchy frost after 5am. Mostly clear, with a low around 38. Northwest wind around 3 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
58°14°–61°16°
Low, likely
35°2°–43°6°
Typical high / low
61°16° / 44°7°
Wind
8 mph13 km/h
UV peak
4
Tomorrow, Oct 25. Sunny. High 62°17°, low 45°7°. Typical 61°16° / 44°7°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 41°5°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 62°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 52°11°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 45°7°
  Dry
Official NWS forecast
Day: Sunny. High near 62, with temperatures falling to around 60 in the afternoon. Northwest wind around 6 mph.
Night: Clear, with a low around 45. West wind around 7 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
60°16°–64°18°
Low, likely
40°4°–45°7°
Typical high / low
61°16° / 44°7°
Wind
8 mph13 km/h, gusts 14 mph23 km/h
UV peak
4
Monday, Oct 26. Sunny. High 64°18°, low 50°10°. Typical 61°16° / 44°7°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 52°11°
  Dry
Official NWS forecast
Day: Sunny, with a high near 64. West wind 7 to 10 mph.
Night: Mostly clear. Low around 50, with temperatures rising to around 52 overnight.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
63°17°–66°19°
Low, likely
40°4°–50°10°
Typical high / low
61°16° / 44°7°
Wind
9 mph14 km/h, gusts 20 mph32 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 59°15°, low 43°6°. Typical 60°16° / 43°6°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 50°10°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 55°13°
  Dry
3. Evening
  6 PM–midnight
  Clear, 49°9°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 45°7°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 59.
Night: Mostly clear, with a low around 43.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
56°13°–59°15°
Low, likely
43°6°–50°10°
Typical high / low
60°16° / 43°6°
Wind
13 mph20 km/h, gusts 24 mph38 km/h
UV peak
4
Wednesday, Oct 28. Partly sunny. High 58°14°, low 48°9°. Typical 60°16° / 43°6°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 45°7°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 56°13°
  Dry
3. Evening
  6 PM–midnight
  Partly cloudy, 51°10°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 52°11°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 58.
Night: Partly cloudy, with a low around 48.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
55°13°–58°14°
Low, likely
39°4°–48°9°
Typical high / low
60°16° / 43°6°
Wind
9 mph15 km/h
UV peak
4
Thursday, Oct 29. Partly sunny. High 63°17°, low 54°12°. Typical 60°16° / 43°6°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 52°11°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 61°16°
  Dry
3. Evening
  6 PM–midnight
  Clear, 57°14°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 55°13°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 63.
Night: Mostly clear, with a low around 54.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
60°16°–63°17°
Low, likely
47°8°–55°13°
Typical high / low
60°16° / 43°6°
Wind
15 mph24 km/h, gusts 22 mph36 km/h
UV peak
4
Friday, Oct 30. Mostly sunny. High 66°19°, low 52°11°. Typical 59°15° / 42°6°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 54°12°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 67°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 58°15°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 52°11°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 66.
Night: Mostly clear, with a low around 52.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
64°18°–69°21°
Low, likely
51°11°–56°13°
Typical high / low
59°15° / 42°6°
Wind
13 mph20 km/h, gusts 26 mph41 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 62°17°, low 52°11°. Typical 59°15° / 42°6°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 53°12°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 56°13°
  Dry
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
57°14°–65°18°
Low, likely
51°11°–53°12°
Typical high / low
59°15° / 42°6°
Wind
12 mph19 km/h, gusts 26 mph42 km/h
UV peak
4
Sunday, Nov 1. Drizzle. High 63°17°, low 56°13°. Typical 58°14° / 42°6°. Rain 0.01 in0.3 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 58°14°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 62°17°
  Dry
3. Evening
  6 PM–midnight
  Drizzle, 60°16°
  30% chance · 0.02 in0.6 mm
4. Overnight
  midnight–6 AM
  Drizzle, 61°16°
  40% chance · 0.12 in2.9 mm
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
59°15°–67°19°
Low, likely
54°12°–59°15°
Typical high / low
58°14° / 42°6°
Wind
14 mph22 km/h, gusts 25 mph40 km/h
UV peak
2
Monday, Nov 2. Drizzle. High 65°18°, low 60°16°. Typical 58°14° / 42°6°. Rain 0.48 in12 mm, 40% chance. Mostly agree.
1. Morning
  6 AM–noon
  Showers, 62°17°
  40% chance · 0.15 in3.7 mm
2. Afternoon
  noon–6 PM
  Showers, 65°18°
  30% chance · 0.14 in3.5 mm
3. Evening
  6 PM–midnight
  Showers, 64°18°
  20% chance · 0.18 in4.6 mm
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
62°17°–68°20°
Low, likely
57°14°–64°18°
Typical high / low
58°14° / 42°6°
Wind
24 mph39 km/h, gusts 33 mph54 km/h

10 days15 days30 days

The outlook

Today
Dry, high 59°, low 38°.
Tomorrow
Dry, high 62°, low 45°, warming up.
Monday
Dry, high 64°, low 50°.
Rest of week
Mostly dry, highs 58–66°.

Want the meteorologists’ reasoning? Read the NWS forecast discussion (OKX) (opens in a new tab)

What changed since yesterday

No meaningful changes from yesterday’s forecast.

Radar

Radar data: NOAA MRMS, rendered by forecast.blue

Radar loads when scrolled into view

Full-screen radar

Rivers

NOAA river gauges within 25 mi

Moriches Bay at Moriches Bay (IN MLLW)

4.8 mi

Below flood stage

Level: 1.7 ft

Reading from Sat 3:48 PM · NWS gauge page

Great South Bay at Watch Hill (IN MLLW)

9.5 mi

Below flood stage

Level: 1.3 ft

Reading from Sat 4 PM · NWS gauge page

Peconic River at Riverhead (IN MLLW)

15 mi

Below flood stage

Level: 1.8 ft

Reading from Sat 3:54 PM · NWS gauge page

Shinnecock Bay at Ponquogue (IN MLLW)

18 mi

Below flood stage

Level: 2.2 ft

Reading from Sat 3:48 PM · NWS gauge page

For your home

What this week’s weather means for heating, cooling, pipes and fresh air.

Heating this week

About 69% less heating than a typical week.

This week 29Typical 93

Heating degree days, base 65°F

Heat-pump hours, next 7 days

h below 47°F: 19
h below 17°F: 0
h below 5°F: 0

47, 17 and 5°F are the test points heat pumps are rated at. About 7 hours are near freezing and damp, when outdoor units defrost more often.

Comfort

Dry air outside (dew point 28°F).

Open the windows?

Sun, 2:00 PM–5:00 PM

Good stretch to open the windows (air quality forecast not available for part of this window).

Is this typical?

Islip-Li Macarthur Airport · official normals 1991–2020 · records 1963–2026

Oct 24, today vs a typical year

Today’s expected high is 2°1° colder than typical.

Last 7 days vs normal

On average 1° colder than normal (daily mean temperature).

−6°−3°SunOct 18
−4°−2°MonOct 19
+3°+1°TueOct 20
+2°+1°WedOct 21
+4°+2°ThuOct 22
−4°−2°FriOct 23
—SatOct 24

Mastic Beach weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

Daylight: 10 h 45 min; Losing 2 min 30 s a day; shortest Dec 21, 1 h 30 min less
Golden hour: 5:19–6:15 PM; Morning 6:55–7:50 AM
Blue hour: 6:15–6:25 PM; Morning 6:44–6:55 AM; first light 6:44 AM

Stars tonight? Fair

Mostly clear 9 PM–6:45 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

98% lit · growing

Today: sets 5:23 AM · rises 4:54 PM
Full moon: Oct 26
New moon: Nov 9

Looking south from Mastic Beach. The highest point on the skyline is about 900 ft, 2 mi away.Skyline from USGS elevation data, heights drawn up to 6× taller. Sky, sun and moon as they are now.

1 active weather alert

Frost Advisory

Mastic Beach, NY weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Monday

Rest of week

What changed since yesterday

Radar

Rivers

Moriches Bay at Moriches Bay (IN MLLW)

Great South Bay at Watch Hill (IN MLLW)

Peconic River at Riverhead (IN MLLW)

Shinnecock Bay at Ponquogue (IN MLLW)

For your home

Heating this week

Heat-pump hours, next 7 days

Comfort

Open the windows?

Is this typical?

Oct 24, today vs a typical year

Last 7 days vs normal

Sun & moon

Sun

Stars tonight? Fair

Moon