Frost Advisory
Starts in 14 h 15 min
When
From 11 PM this evening to 9 AM EDT Saturday.
Where
In Connecticut, Southern Fairfield, Southern Middlesex, Southern New Haven, and Southern New London Counties. In New York, Southern Westchester County.
Issued for this forecast zone · National Weather Service Upton NY
What, impacts and precautionsHide details
What
Temperatures as low as 33 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; Southern Westchester
See it on weather.gov (opens in a new tab)

Observed 7:50 AM EDT at KHPN

Greenville, NY weather

Sunny and 43°6°.

Forecasts agree

Now 43°6°

Sunny · Feels like 38°3°

Wind: 8 mph13 km/h; From the north-northwest. 58–8 mph13 km/h through 8 PM
Dew point: 37°3°; Comfortable
UV index: 1Low; Moderate 11 AM–4 PM · peak 4
Air quality: 45Good; Main pollutant: PM2.5 (fine particles)
Pressure: 30.3 inHg1026 hPa; Rising · +0.09 inHg+3.0 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

Good hours for

High 57°14° today at 1 PM
Below 50°10° tonight after 8 PM
Above 50°10° tomorrow by 10 AM

This morningUp to 53°12° by 11 AM · Clear
This afternoonNear 56°13° · Clear
TonightDown to 39°4° by 1 AM · Partly cloudy
Tomorrow morningUp to 54°12° by 11 AM · Partly cloudy
Tomorrow afternoonUp to 60°16° by 2 PM · Partly cloudy
Tomorrow nightDown to 38°3° by 3 AM · Clear

Hourly forecast, next 48 hours, in the place's local time
Hour	Conditions	Temperature	Feels like	Precipitation	Wind	Humidity	Cloud cover	UV index
Fri 8a	Sunny	44°7° (likely 44°7° to 45°7°)	39°4°	0%	8 mph13 km/h from N, gusts 14 mph23 km/h	70%	0%	0
Fri 9a	Sunny	46°8° (likely 46°8° to 49°9°)	42°6°	0%	8 mph13 km/h from NE, gusts 17 mph27 km/h	63%	0%	1
Fri 10a	Sunny	50°10° (likely 50°10° to 52°11°)	47°8°	0%	7 mph11 km/h from NE, gusts 17 mph28 km/h	52%	0%	2
Fri 11a	Sunny	53°12° (likely 53°12° to 54°12°)	53°12°	0%	7 mph11 km/h from NE, gusts 16 mph26 km/h	45%	0%	3
Fri 12p	Sunny	55°13° (likely 55°13° to 56°13°)	55°13°	0%	7 mph11 km/h from NE, gusts 14 mph23 km/h	40%	0%	4
Fri 1p	Sunny	57°14° (likely 56°13° to 58°14°)	57°14°	0%	7 mph11 km/h from N, gusts 11 mph17 km/h	35%	0%	4
Fri 2p	Sunny	57°14° (likely 57°14° to 59°15°)	57°14°	0%	6 mph10 km/h from N, gusts 9 mph14 km/h	35%	1%	4
Fri 3p	Sunny	57°14° (likely 57°14° to 59°15°)	57°14°	0%	6 mph10 km/h from N, gusts 11 mph17 km/h	35%	0%	3
Fri 4p	Sunny	57°14° (likely 57°14° to 59°15°)	57°14°	0%	6 mph10 km/h from N, gusts 10 mph16 km/h	35%	0%	2
Fri 5p	Sunny	57°14° (likely 56°13° to 58°14°)	57°14°	0%	6 mph10 km/h from N, gusts 9 mph15 km/h	35%	0%	1
Fri 6p	Clear	55°13° (likely 53°12° to 55°13°)	55°13°	0%	6 mph10 km/h from N, gusts 6 mph10 km/h	40%	6%	0
Fri 7p	Clear	51°11° (likely 49°9° to 51°11°)	51°11°	0%	5 mph8 km/h from N, gusts 7 mph11 km/h	46%	14%	0
Fri 8p	Mostly clear	47°8° (likely 46°8° to 48°9°)	45°7°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	56%	47%	0
Fri 9p	Cloudy	44°7° (likely 44°7° to 47°8°)	41°5°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	62%	58%	0
Fri 10p	Mostly clear	43°6° (likely 43°6° to 46°8°)	40°4°	0%	5 mph8 km/h from N, gusts 5 mph9 km/h	65%	56%	0
Fri 11p	Partly cloudy	41°5° (likely 41°5° to 45°7°)	38°3°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	70%	24%	0
Sat 12a	Partly cloudy	40°4° (likely 40°4° to 44°7°)	37°3°	0%	5 mph8 km/h from N, gusts 5 mph8 km/h	73%	31%	0
Sat 1a	Mostly clear	39°4° (likely 39°4° to 43°6°)	36°2°	0%	5 mph8 km/h from N, gusts 4 mph7 km/h	73%	40%	0
Sat 2a	Mostly clear	39°4° (likely 39°4° to 42°6°)	36°2°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	73%	47%	0
Sat 3a	Mostly clear	39°4° (likely 37°3° to 41°5°)	36°2°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	73%	48%	0
Sat 4a	Partly cloudy	39°4° (likely 36°2° to 41°5°)	36°2°	0%	5 mph8 km/h from N, gusts 6 mph10 km/h	70%	55%	0
Sat 5a	Cloudy	39°4° (likely 36°2° to 40°4°)	36°2°	0%	5 mph8 km/h from N, gusts 6 mph9 km/h	70%	64%	0
Sat 6a	Partly cloudy	39°4° (likely 36°2° to 40°4°)	36°2°	0%	5 mph8 km/h from N, gusts 5 mph8 km/h	70%	55%	0
Sat 7a	Mostly sunny	37°3° (likely 35°2° to 39°4°)	33°1°	0%	5 mph8 km/h from N, gusts 5 mph8 km/h	79%	48%	0
Sat 8a	Partly sunny	39°4° (likely 35°2° to 40°4°)	36°2°	0%	5 mph8 km/h from N, gusts 5 mph8 km/h	73%	46%	0
Sat 9a	Partly sunny	43°6° (likely 42°6° to 44°7°)	40°4°	0%	5 mph8 km/h from N, gusts 5 mph8 km/h	62%	64%	1
Sat 10a	Partly sunny	50°10° (likely 48°9° to 50°10°)	49°9°	0%	3 mph5 km/h from N, gusts 4 mph6 km/h	48%	67%	1
Sat 11a	Cloudy	54°12° (likely 53°12° to 54°12°)	54°12°	0%	3 mph5 km/h from N, gusts 5 mph9 km/h	41%	66%	3
Sat 12p	Cloudy	56°13° (likely 55°13° to 57°14°)	56°13°	0%	3 mph5 km/h from NW, gusts 5 mph9 km/h	38%	55%	3
Sat 1p	Cloudy	59°15° (likely 57°14° to 59°15°)	59°15°	0%	3 mph5 km/h from NW, gusts 5 mph8 km/h	34%	61%	4
Sat 2p	Partly sunny	60°16° (likely 59°15° to 61°16°)	60°16°	0%	3 mph5 km/h from NW, gusts 5 mph7 km/h	33%	62%	3
Sat 3p	Partly sunny	59°15° (likely 59°15° to 61°16°)	59°15°	0%	3 mph5 km/h from NW, gusts 5 mph7 km/h	34%	54%	3
Sat 4p	Mostly sunny	60°16° (likely 59°15° to 61°16°)	60°16°	0%	3 mph5 km/h from NW, gusts 5 mph7 km/h	32%	52%	2
Sat 5p	Mostly sunny	59°15° (likely 58°14° to 60°16°)	59°15°	0%	2 mph3 km/h from NW, gusts 4 mph6 km/h	33%	50%	1
Sat 6p	Mostly clear	56°13° (likely 53°12° to 56°13°)	56°13°	0%	1 mph2 km/h from NW, gusts 4 mph6 km/h	38%	41%	0
Sat 7p	Mostly clear	53°12° (likely 51°11° to 53°12°)	53°12°	0%	0 mph0 km/h, gusts 3 mph4 km/h	45%	25%	0
Sat 8p	Clear	47°8° (likely 47°8° to 51°11°)	47°8°	0%	1 mph2 km/h from NW, gusts 5 mph7 km/h	58%	3%	0
Sat 9p	Clear	45°7° (likely 45°7° to 49°9°)	45°7°	0%	1 mph2 km/h from NW, gusts 7 mph11 km/h	63%	1%	0
Sat 10p	Clear	43°6° (likely 43°6° to 47°8°)	43°6°	0%	1 mph2 km/h from NW, gusts 7 mph12 km/h	70%	1%	0
Sat 11p	Clear	42°6° (likely 42°6° to 46°8°)	42°6°	0%	1 mph2 km/h from NW, gusts 6 mph10 km/h	73%	0%	0
Sun 12a	Clear	41°5° (likely 41°5° to 45°7°)	41°5°	0%	1 mph2 km/h from NW, gusts 6 mph9 km/h	76%	0%	0
Sun 1a	Clear	39°4° (likely 39°4° to 45°7°)	39°4°	0%	2 mph3 km/h from NW, gusts 5 mph9 km/h	85%	0%	0
Sun 2a	Clear	39°4° (likely 39°4° to 46°8°)	39°4°	0%	2 mph3 km/h from NW, gusts 5 mph9 km/h	85%	0%	0
Sun 3a	Clear	38°3° (likely 34°1° to 50°10°)	38°3°	0%	2 mph3 km/h from NW, gusts 4 mph7 km/h	85%	0%	0
Sun 4a	Clear	38°3° (likely 32°0° to 49°9°)	36°2°	0%	3 mph5 km/h from NW, gusts 5 mph7 km/h	85%	13%	0
Sun 5a	Clear	38°3° (likely 31°−1° to 49°9°)	36°2°	0%	3 mph5 km/h from NW, gusts 4 mph7 km/h	82%	15%	0
Sun 6a	Clear	37°3° (likely 31°−1° to 48°9°)	34°1°	0%	3 mph5 km/h from NW, gusts 4 mph7 km/h	85%	16%	0
Sun 7a	Sunny	37°3° (likely 31°−1° to 48°9°)	34°1°	0%	3 mph5 km/h from NW, gusts 5 mph7 km/h	89%	15%	0

Days ahead

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

Today, Oct 23. Sunny. High 57°14°, low 37°3°. Typical 63°17° / 51°11°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Sunny, 44°7°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 57°14°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 47°8°
  Dry
4. Overnight
  midnight–6 AM
  Mostly clear, 39°4°
  Dry
Official NWS forecast
Today: Sunny, with a high near 57. North wind around 8 mph.
Tonight: Areas of frost after 4am. Mostly clear. Low around 37, with temperatures rising to around 39 overnight. North wind around 6 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
57°14°–59°15°
Low, likely
37°3°–44°7°
Typical high / low
63°17° / 51°11°
Wind
10 mph16 km/h, gusts 27 mph43 km/h
UV peak
4
Tomorrow, Oct 24. Partly sunny. High 60°16°, low 37°3°. Typical 63°17° / 50°10°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Partly sunny, 39°4°
  Dry
2. Afternoon
  noon–6 PM
  Partly sunny, 60°16°
  Dry
3. Evening
  6 PM–midnight
  Clear, 47°8°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 38°3°
  Dry
Official NWS forecast
Day: Areas of frost before 9am. Mostly sunny, with a high near 60. Northwest wind around 5 mph.
Night: Mostly clear, with a low around 37. Northwest wind 0 to 3 mph.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
59°15°–61°16°
Low, likely
35°2°–39°4°
Typical high / low
63°17° / 50°10°
Wind
6 mph10 km/h, gusts 12 mph19 km/h
UV peak
4
Sunday, Oct 25. Sunny. High 64°18°, low 40°4°. Typical 63°17° / 50°10°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 39°4°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 63°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 52°11°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 41°5°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Patchy frost before 8am. Sunny. High near 64, with temperatures falling to around 62 in the afternoon. West wind around 3 mph.
Night: Clear. Low around 40, with temperatures rising to around 42 overnight.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
61°16°–65°18°
Low, likely
33°1°–43°6°
Typical high / low
63°17° / 50°10°
Wind
6 mph9 km/h
UV peak
4
Monday, Oct 26. Sunny. High 68°20°, low 46°8°. Typical 62°17° / 50°10°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 40°4°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 67°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 59°15°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 51°10°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 68.
Night: Clear, with a low around 46.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
66°19°–69°21°
Low, likely
32°0°–47°8°
Typical high / low
62°17° / 50°10°
Wind
7 mph11 km/h, gusts 15 mph24 km/h
UV peak
4
Tuesday, Oct 27. Mostly sunny. High 60°16°, low 39°4°. Typical 62°17° / 49°9°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 49°9°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 59°15°
  Dry
3. Evening
  6 PM–midnight
  Clear, 51°11°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 43°6°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 60.
Night: Mostly clear, with a low around 39.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
57°14°–62°17°
Low, likely
39°4°–49°9°
Typical high / low
62°17° / 49°9°
Wind
10 mph17 km/h, gusts 26 mph41 km/h
UV peak
4
Wednesday, Oct 28. Partly sunny. High 57°14°, low 43°6°. Typical 62°17° / 49°9°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 43°6°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 57°14°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 52°11°
  Dry
4. Overnight
  midnight–6 AM
  Partly cloudy, 49°9°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 57.
Night: Partly cloudy, with a low around 43.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
55°13°–59°15°
Low, likely
38°3°–48°9°
Typical high / low
62°17° / 49°9°
Wind
8 mph12 km/h, gusts 13 mph21 km/h
UV peak
2
Thursday, Oct 29. Partly sunny. High 63°17°, low 46°8°. Typical 61°16° / 49°9°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 49°9°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 57°14°
  Dry
4. Overnight
  midnight–6 AM
  Mostly clear, 50°10°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 63.
Night: Partly cloudy, with a low around 46.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
61°16°–67°19°
Low, likely
43°6°–52°11°
Typical high / low
61°16° / 49°9°
Wind
12 mph19 km/h, gusts 28 mph45 km/h
UV peak
4
Friday, Oct 30. Cloudy. High 67°19°, low 51°11°. Typical 61°16° / 48°9°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 50°10°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Mostly clear, 58°15°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 50°10°
  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
62°17°–69°21°
Low, likely
49°9°–53°12°
Typical high / low
61°16° / 48°9°
Wind
10 mph16 km/h, gusts 23 mph36 km/h
UV peak
4
Saturday, Oct 31. Mostly sunny. High 58°14°, low 48°9°. Typical 60°16° / 48°9°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 50°10°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 57°14°
  Dry
3. Evening
  6 PM–midnight
  Clear, 50°10°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 44°7°
  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
52°11°–64°18°
Low, likely
42°6°–58°14°
Typical high / low
60°16° / 48°9°
Wind
10 mph16 km/h, gusts 24 mph38 km/h
UV peak
3
Sunday, Nov 1. Rain. High 59°15°, low 48°9°. Typical 60°16° / 48°9°. Rain 0.19 in4.8 mm, 30% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 44°7°
  Dry
2. Afternoon
  noon–6 PM
  Drizzle, 55°13°
  20% chance · 0.04 in0.9 mm
3. Evening
  6 PM–midnight
  Rain, 51°11°
  20% chance · 0.12 in3 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
56°13°–63°17°
Low, likely
39°4°–56°13°
Typical high / low
60°16° / 48°9°
Wind
13 mph20 km/h, gusts 24 mph39 km/h

10 days15 days30 days

The outlook

Today
Dry, high 57°, low 37°.
Tomorrow
Dry, high 60°, low 37°, warming up.
Sunday
Dry, high 64°, low 40°, warming up.
Rest of week
Mostly dry, highs 57–68°.

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

Little Neck Bay at Kings Point (IN MLLW)

13 mi

Below flood stage

Level: 7.9 ft

Forecast peak 9.2 ft Fri 9 AM

Reading from Fri 7:36 AM · NWS gauge page

Hudson River at Piermont (IN MLLW)

5.1 mi

Below flood stage

Level: 4.8 ft

Reading from Fri 7:30 AM · NWS gauge page

Long Island Sound at Rye (IN MLLW)

8.0 mi

Below flood stage

Level: 7.9 ft

Reading from Fri 7:42 AM · NWS gauge page

Hackensack River at Rivervale

8.9 mi

Below flood stage

Level: 1.8 ft
Flow: 45 cfs

Reading from Fri 7:15 AM · NWS gauge page

For your home

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

Heating this week

About 44% less heating than a typical week.

This week 35Typical 63

Heating degree days, base 65°F

Heat-pump hours, next 7 days

h below 47°F: 27
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 37°F).

Open the windows?

No stretch in the next few days is comfortable enough outside, by temperature, dew point and air quality.

Is this typical?

Laguardia Airport · official normals 1991–2020 · records 1939–2026

Oct 23, today vs a typical year

Today’s expected high is 6°3° colder than typical.

Last 7 days vs normal

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

−5°−3°SatOct 17
−7°−4°SunOct 18
−2°−1°MonOct 19
+4°+2°TueOct 20
±0°WedOct 21
+2°+1°ThuOct 22
—FriOct 23

Greenville weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

Daylight: 10 h 47 min; Losing 2 min 30 s a day; shortest Dec 21, 1 h 34 min less
Golden hour: 5:24–6:20 PM; Morning 6:58–7:53 AM
Blue hour: 6:20–6:30 PM; Morning 6:47–6:58 AM; first light 6:47 AM

Stars tonight? Fair

Mostly clear 6:30–8 PM, but the moon is 95% lit and up.

Moon

Waxing gibbous

91% lit · growing

Today: sets 4:18 AM · rises 4:34 PM
Full moon: Oct 26
New moon: Nov 9

Looking southeast from Greenville. Water in view.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

Greenville, NY weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Sunday

Rest of week

What changed since yesterday

Radar

Rivers

Little Neck Bay at Kings Point (IN MLLW)

Hudson River at Piermont (IN MLLW)

Long Island Sound at Rye (IN MLLW)

Hackensack River at Rivervale

For your home

Heating this week

Heat-pump hours, next 7 days

Comfort

Open the windows?

Is this typical?

Oct 23, today vs a typical year

Last 7 days vs normal

Sun & moon

Sun

Stars tonight? Fair

Moon