Long Island Sound near New London Harbor (IN MLLW)
2.9 mi- Level
- 2.5 ft
Forecast peak 4.3 ft Sat 9 AM
Reading from Fri 11:54 PM · NWS gauge page
1 active weather alert
Frost Advisory
Ends in 7 h 39 min
- When
- Until 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 the mid 30s 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 1:05 AM EDT at KGON
Groton, CT weather
Clear and 37°3°.
Today: low 40°4° (likely 33°1° to 40°4°), high 60°16° (likely 59°15° to 62°17°).
Now 37°3°
Clear
- Wind
- 3 mph5 km/h
- From the north. 35–6 mph10 km/h through 1 PM
- Dew point
- 34°1°
- Dry, static shocks likely
- UV index
- 0Low
- Moderate 11 AM–4 PM · peak 4
- Air quality
- 33Good
- Main pollutant: PM2.5 (fine particles)
- Pressure
- 30.48 inHg1032 hPa
- Rising slowly · +0.02 inHg+0.7 hPa next 3 h
Next 2 hours
No precipitation expected in the next 2 hours.
From forecast models
Next 48 hours
17°9° cooler than this time yesterday (54°12° then, 37°3° now)
Good hours for
TonightNear 43°6° · Clear
This morningUp to 54°12° by 11 AM · Partly cloudy
This afternoonNear 57°14° · Partly cloudy
TonightDown to 41°5° by 5 AM · Clear
Tomorrow morningUp to 55°13° by 11 AM · Clear
Tomorrow afternoonNear 58°14° · Clear
Tomorrow nightDown to 49°9° by midnight · Clear
| Hour | Conditions | Temperature | Feels like | Precipitation | Wind | Humidity | Cloud cover | UV index |
|---|---|---|---|---|---|---|---|---|
| Sat 1a | Clear | 44°7° (likely 35°2° to 44°7°) | 41°5° | 0% | 5 mph8 km/h from N, gusts 4 mph6 km/h | 82% | 1% | 0 |
| Sat 2a | Clear | 43°6° (likely 35°2° to 43°6°) | 40°4° | 0% | 5 mph8 km/h from N, gusts 6 mph9 km/h | 86% | 2% | 0 |
| Sat 3a | Clear | 43°6° (likely 34°1° to 43°6°) | 40°4° | 0% | 5 mph8 km/h from N, gusts 7 mph11 km/h | 86% | 3% | 0 |
| Sat 4a | Clear | 42°6° (likely 34°1° to 42°6°) | 38°3° | 0% | 6 mph10 km/h from N, gusts 9 mph15 km/h | 89% | 1% | 0 |
| Sat 5a | Clear | 41°5° (likely 34°1° to 41°5°) | 37°3° | 0% | 6 mph10 km/h from N, gusts 10 mph15 km/h | 92% | 3% | 0 |
| Sat 6a | Clear | 40°4° (likely 33°1° to 40°4°) | 36°2° | 0% | 6 mph10 km/h from N, gusts 10 mph16 km/h | 92% | 23% | 0 |
| Sat 7a | Partly sunny | 40°4° (likely 33°1° to 40°4°) | 37°3° | 0% | 5 mph8 km/h from N, gusts 11 mph17 km/h | 92% | 69% | 0 |
| Sat 8a | Cloudy | 41°5° (likely 34°1° to 41°5°) | 38°3° | 0% | 5 mph8 km/h from N, gusts 10 mph16 km/h | 85% | 78% | 0 |
| Sat 9a | Cloudy | 45°7° (likely 41°5° to 45°7°) | 43°6° | 0% | 5 mph8 km/h from N, gusts 8 mph13 km/h | 76% | 75% | 1 |
| Sat 10a | Mostly sunny | 50°10° (likely 47°8° to 50°10°) | 48°9° | 0% | 5 mph8 km/h from N, gusts 9 mph14 km/h | 63% | 55% | 2 |
| Sat 11a | Partly sunny | 54°12° (likely 52°11° to 55°13°) | 54°12° | 0% | 5 mph8 km/h from NW, gusts 10 mph16 km/h | 54% | 50% | 3 |
| Sat 12p | Mostly sunny | 57°14° (likely 55°13° to 58°14°) | 57°14° | 0% | 5 mph8 km/h from W, gusts 9 mph14 km/h | 47% | 48% | 4 |
| Sat 1p | Mostly sunny | 56°13° (likely 56°13° to 60°16°) | 56°13° | 0% | 5 mph8 km/h from W, gusts 9 mph14 km/h | 51% | 44% | 4 |
| Sat 2p | Partly sunny | 57°14° (likely 57°14° to 61°16°) | 57°14° | 0% | 6 mph10 km/h from W, gusts 8 mph13 km/h | 51% | 46% | 4 |
| Sat 3p | Partly sunny | 58°14° (likely 58°14° to 62°17°) | 58°14° | 0% | 6 mph10 km/h from W, gusts 9 mph14 km/h | 53% | 40% | 3 |
| Sat 4p | Sunny | 58°14° (likely 58°14° to 61°16°) | 58°14° | 0% | 6 mph10 km/h from W, gusts 8 mph14 km/h | 53% | 19% | 2 |
| Sat 5p | Mostly sunny | 57°14° (likely 57°14° to 59°15°) | 57°14° | 0% | 6 mph10 km/h from W, gusts 8 mph13 km/h | 57% | 9% | 1 |
| Sat 6p | Clear | 55°13° (likely 53°12° to 55°13°) | 55°13° | 0% | 5 mph8 km/h from W, gusts 8 mph13 km/h | 61% | 26% | 0 |
| Sat 7p | Clear | 53°12° (likely 50°10° to 53°12°) | 53°12° | 0% | 5 mph8 km/h from W, gusts 8 mph14 km/h | 66% | 6% | 0 |
| Sat 8p | Clear | 52°11° (likely 47°8° to 52°11°) | 52°11° | 0% | 5 mph8 km/h from NW, gusts 8 mph12 km/h | 71% | 1% | 0 |
| Sat 9p | Clear | 51°11° (likely 44°7° to 51°11°) | 51°11° | 0% | 5 mph8 km/h from NW, gusts 7 mph11 km/h | 71% | 0% | 0 |
| Sat 10p | Clear | 49°9° (likely 43°6° to 49°9°) | 47°8° | 0% | 5 mph8 km/h from NW, gusts 7 mph11 km/h | 77% | 0% | 0 |
| Sat 11p | Clear | 48°9° (likely 42°6° to 48°9°) | 46°8° | 0% | 5 mph8 km/h from NW, gusts 7 mph11 km/h | 80% | 0% | 0 |
| Sun 12a | Clear | 46°8° (likely 41°5° to 46°8°) | 44°7° | 0% | 5 mph8 km/h from NW, gusts 6 mph10 km/h | 86% | 0% | 0 |
| Sun 1a | Clear | 45°7° (likely 40°4° to 45°7°) | 43°6° | 0% | 5 mph8 km/h from N, gusts 7 mph11 km/h | 86% | 0% | 0 |
| Sun 2a | Clear | 44°7° (likely 39°4° to 44°7°) | 41°5° | 0% | 5 mph8 km/h from N, gusts 7 mph12 km/h | 86% | 0% | 0 |
| Sun 3a | Clear | 43°6° (likely 39°4° to 43°6°) | 40°4° | 0% | 5 mph8 km/h from N, gusts 8 mph12 km/h | 89% | 0% | 0 |
| Sun 4a | Clear | 42°6° (likely 38°3° to 42°6°) | 39°4° | 0% | 5 mph8 km/h from N, gusts 8 mph12 km/h | 89% | 0% | 0 |
| Sun 5a | Clear | 41°5° (likely 37°3° to 41°5°) | 38°3° | 0% | 5 mph8 km/h from N, gusts 8 mph13 km/h | 93% | 0% | 0 |
| Sun 6a | Clear | 41°5° (likely 36°2° to 41°5°) | 38°3° | 0% | 5 mph8 km/h from N, gusts 7 mph12 km/h | 89% | 0% | 0 |
| Sun 7a | Sunny | 40°4° (likely 35°2° to 40°4°) | 37°3° | 0% | 5 mph8 km/h from N, gusts 8 mph13 km/h | 96% | 0% | 0 |
| Sun 8a | Sunny | 42°6° (likely 35°2° to 42°6°) | 39°4° | 0% | 5 mph8 km/h from N, gusts 7 mph12 km/h | 89% | 0% | 0 |
| Sun 9a | Sunny | 46°8° (likely 43°6° to 46°8°) | 44°7° | 0% | 5 mph8 km/h from N, gusts 7 mph11 km/h | 79% | 0% | 1 |
| Sun 10a | Sunny | 51°11° (likely 51°11° to 53°12°) | 51°11° | 0% | 5 mph8 km/h from N, gusts 7 mph10 km/h | 68% | 0% | 2 |
| Sun 11a | Sunny | 55°13° (likely 55°13° to 59°15°) | 55°13° | 0% | 5 mph8 km/h from NW, gusts 5 mph7 km/h | 59% | 0% | 3 |
| Sun 12p | Sunny | 57°14° (likely 57°14° to 62°17°) | 57°14° | 0% | 5 mph8 km/h from NW, gusts 6 mph10 km/h | 57% | 0% | 4 |
| Sun 1p | Sunny | 59°15° (likely 59°15° to 63°17°) | 59°15° | 0% | 5 mph8 km/h from W, gusts 8 mph13 km/h | 53% | 0% | 4 |
| Sun 2p | Sunny | 59°15° (likely 59°15° to 64°18°) | 59°15° | 0% | 5 mph8 km/h from SW, gusts 10 mph16 km/h | 55% | 0% | 4 |
| Sun 3p | Sunny | 59°15° (likely 59°15° to 63°17°) | 59°15° | 0% | 5 mph8 km/h from SW, gusts 11 mph17 km/h | 55% | 0% | 3 |
| Sun 4p | Sunny | 59°15° (likely 59°15° to 62°17°) | 59°15° | 0% | 5 mph8 km/h from SW, gusts 11 mph18 km/h | 57% | 0% | 2 |
| Sun 5p | Sunny | 58°14° (likely 58°14° to 60°16°) | 58°14° | 0% | 5 mph8 km/h from SW, gusts 11 mph18 km/h | 60% | 0% | 1 |
| Sun 6p | Clear | 56°13° (likely 53°12° to 56°13°) | 56°13° | 0% | 5 mph8 km/h from SW, gusts 10 mph15 km/h | 66% | 0% | 0 |
| Sun 7p | Clear | 55°13° (likely 50°10° to 55°13°) | 55°13° | 0% | 5 mph8 km/h from SW, gusts 8 mph12 km/h | 69% | 0% | 0 |
| Sun 8p | Clear | 53°12° (likely 48°9° to 53°12°) | 53°12° | 0% | 5 mph8 km/h from SW, gusts 6 mph10 km/h | 77% | 0% | 0 |
| Sun 9p | Clear | 52°11° (likely 46°8° to 52°11°) | 52°11° | 0% | 5 mph8 km/h from SW, gusts 4 mph6 km/h | 80% | 0% | 0 |
| Sun 10p | Clear | 51°11° (likely 45°7° to 52°11°) | 51°11° | 0% | 5 mph8 km/h from SW, gusts 4 mph7 km/h | 86% | 0% | 0 |
| Sun 11p | Clear | 50°10° (likely 45°7° to 52°11°) | 48°9° | 0% | 5 mph8 km/h from SW, gusts 4 mph6 km/h | 89% | 0% | 0 |
| Mon 12a | Clear | 49°9° (likely 45°7° to 52°11°) | 47°8° | 0% | 5 mph8 km/h from W, gusts 4 mph7 km/h | 93% | 0% | 0 |
Days ahead
Shaded: typical range for these dates (1991–2020)
Today, Oct 24. Cloudy. High 60°16°, low 40°4°. Typical 61°16° / 41°5°. Dry. Mostly agree.
Morning
6 AM–noon
Cloudy, 41°5°Dry
Afternoon
noon–6 PM
Partly sunny, 58°14°Dry
Evening
6 PM–midnight
Clear, 52°11°Dry
Overnight
midnight–6 AM
Clear, 41°5°Dry
Official NWS forecast
Today: Mostly sunny. High near 60, with temperatures falling to around 57 in the afternoon. Northwest wind around 6 mph.
Tonight: Mostly clear, with a low around 40. North wind around 6 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 59°15°–62°17°
- Low, likely
- 33°1°–40°4°
- Typical high / low
- 61°16° / 41°5°
- Wind
- 7 mph12 km/h, gusts 15 mph24 km/h
- UV peak
- 4
Tomorrow, Oct 25. Sunny. High 61°16°, low 45°7°. Typical 61°16° / 40°4°. Dry. Mostly agree.
Morning
6 AM–noon
Sunny, 42°6°Dry
Afternoon
noon–6 PM
Sunny, 59°15°Dry
Evening
6 PM–midnight
Clear, 53°12°Dry
Overnight
midnight–6 AM
Clear, 46°8°Dry
Official NWS forecast
Day: Sunny. High near 61, with temperatures falling to around 58 in the afternoon. West wind around 5 mph.
Night: Clear, with a low around 45. Southwest wind around 5 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 60°16°–64°18°
- Low, likely
- 35°2°–45°7°
- Typical high / low
- 61°16° / 40°4°
- Wind
- 10 mph16 km/h
- UV peak
- 4
Monday, Oct 26. Sunny. High 65°18°, low 47°8°. Typical 60°16° / 40°4°. Dry. Mostly agree.
Morning
6 AM–noon
Sunny, 45°7°Dry
Afternoon
noon–6 PM
Sunny, 66°19°Dry
Evening
6 PM–midnight
Clear, 55°13°Dry
Overnight
midnight–6 AM
Clear, 50°10°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny. High near 65, with temperatures falling to around 62 in the afternoon.
Night: Clear, with a low around 47.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 62°17°–67°19°
- Low, likely
- 41°5°–48°9°
- Typical high / low
- 60°16° / 40°4°
- Wind
- 11 mph17 km/h, gusts 28 mph45 km/h
- UV peak
- 4
Tuesday, Oct 27. Mostly sunny. High 59°15°, low 38°3°. Typical 60°16° / 40°4°. Dry. Mostly agree.
Morning
6 AM–noon
Sunny, 46°8°Dry
Afternoon
noon–6 PM
Sunny, 56°13°Dry
Evening
6 PM–midnight
Clear, 45°7°Dry
Overnight
midnight–6 AM
Clear, 36°2°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 38.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 55°13°–59°15°
- Low, likely
- 38°3°–46°8°
- Typical high / low
- 60°16° / 40°4°
- Wind
- 14 mph22 km/h, gusts 27 mph43 km/h
- UV peak
- 4
Wednesday, Oct 28. Partly sunny. High 56°13°, low 45°7°. Typical 60°16° / 39°4°. Dry. Forecasts agree.
Morning
6 AM–noon
Sunny, 36°2°Dry
Afternoon
noon–6 PM
Sunny, 54°12°Dry
Evening
6 PM–midnight
Mostly clear, 46°8°Dry
Overnight
midnight–6 AM
Cloudy, 45°7°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 56.
Night: Partly cloudy, with a low around 45.
Forecasts agreeIndependent forecasts are close; the range is narrow.
- High, likely
- 52°11°–56°13°
- Low, likely
- 31°−1°–45°7°
- Typical high / low
- 60°16° / 39°4°
- Wind
- 10 mph16 km/h, gusts 17 mph27 km/h
- UV peak
- 4
Thursday, Oct 29. Partly sunny. High 62°17°, low 51°11°. Typical 59°15° / 39°4°. Dry. Forecasts differ.
Morning
6 AM–noon
Partly sunny, 47°8°Dry
Afternoon
noon–6 PM
Sunny, 60°16°Dry
Evening
6 PM–midnight
Clear, 55°13°Dry
Overnight
midnight–6 AM
Clear, 52°11°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 62.
Night: Partly cloudy, with a low around 51.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
- High, likely
- 56°13°–63°17°
- Low, likely
- 43°6°–51°11°
- Typical high / low
- 59°15° / 39°4°
- Wind
- 11 mph18 km/h, gusts 32 mph52 km/h
- UV peak
- 4
Friday, Oct 30. Partly sunny. High 64°18°, low 50°10°. Typical 59°15° / 39°4°. Dry. Mostly agree.
Morning
6 AM–noon
Sunny, 50°10°Dry
Afternoon
noon–6 PM
Sunny, 66°19°Dry
Evening
6 PM–midnight
Clear, 55°13°Dry
Overnight
midnight–6 AM
Clear, 46°8°Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 64.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 63°17°–67°19°
- Low, likely
- 48°9°–53°12°
- Typical high / low
- 59°15° / 39°4°
- Wind
- 10 mph16 km/h, gusts 21 mph33 km/h
- UV peak
- 4
Saturday, Oct 31. Mostly sunny. High 62°17°, low 47°8°. Typical 58°14° / 38°3°. Dry. Mostly agree.
Morning
6 AM–noon
Sunny, 45°7°Dry
Afternoon
noon–6 PM
Mostly sunny, 62°17°Dry
Evening
6 PM–midnight
Clear, 51°10°Dry
Overnight
midnight–6 AM
Mostly clear, 47°8°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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
- High, likely
- 61°16°–64°18°
- Low, likely
- 43°6°–54°12°
- Typical high / low
- 58°14° / 38°3°
- Wind
- 16 mph26 km/h, gusts 26 mph41 km/h
- UV peak
- 4
Sunday, Nov 1. Cloudy. High 61°16°, low 49°9°. Typical 58°14° / 38°3°. Rain 0.01 in0.3 mm, 20% chance. Mostly agree.
Morning
6 AM–noon
Sunny, 49°9°Dry
Afternoon
noon–6 PM
Sunny, 61°16°Dry
Evening
6 PM–midnight
Clear, 52°11°20% chance
Overnight
midnight–6 AM
Cloudy, 52°11°30% chance
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
- 58°14°–65°18°
- Low, likely
- 42°6°–56°13°
- Typical high / low
- 58°14° / 38°3°
- Wind
- 13 mph21 km/h, gusts 26 mph42 km/h
- UV peak
- 4
Monday, Nov 2. Drizzle. High 62°17°, low 51°11°. Typical 58°14° / 38°3°. Rain 0.09 in2.3 mm, 30% chance. Forecasts differ.
Morning
6 AM–noon
Cloudy, 52°11°30% chance
Afternoon
noon–6 PM
Cloudy, 60°16°30% chance · 0.02 in0.5 mm
Evening
6 PM–midnight
Drizzle, 58°15°30% chance · 0.21 in5.3 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
- 54°12°–69°21°
- Low, likely
- 38°3°–59°15°
- Typical high / low
- 58°14° / 38°3°
- Wind
- 15 mph24 km/h, gusts 33 mph54 km/h
- UV peak
- 3
The outlook
Today
Dry, high 60°, low 40°.
Tomorrow
Dry, high 61°, low 45°.
Monday
Dry, high 65°, low 47°, warming up.
Rest of week
Mostly dry, highs 56–64°.
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
Rivers
NOAA river gauges within 25 mi
Below flood stage
Atlantic Coast at Watch Hill Cove (IN MLLW)
11 mi- Level
- 2.2 ft
Forecast peak 3.9 ft Sat 8 AM
Reading from Fri 11 PM · NWS gauge page
Pawcatuck at Westerly
13 mi- Level
- 4.4 ft
- Flow
- 420 cfs
Forecast peak 4.4 ft Sat 2 AM
Reading from Fri 11 PM · NWS gauge page
Yantic River at Yantic
16 mi- Level
- 2.0 ft
- Flow
- 90 cfs
Forecast peak 2.0 ft Sat 2 AM
Reading from Fri 11:45 PM · NWS gauge page
For your home
What this week’s weather means for heating, cooling, pipes and fresh air.
Heating this week
About 72% less heating than a typical week.
This week 30Typical 106
Heating degree days, base 65°F
Heat-pump hours, next 7 days
- h below 47°F
- 18
- 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 10 hours are near freezing and damp, when outdoor units defrost more often.
Comfort
Dry air outside (dew point 34°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?
NORWICH PUBLIC UTILITY PLANT · official normals 1991–2020 · records 1956–2026
Oct 24, today vs a typical year
Today’s expected high is about typical for the date.
- Normal high / low
- 61°16° / 41°5°
- Forecast high / low
- 60°16° / 40°4°
- Record high
- 77°25° in 1985
- Record low
- 24°−4° in 1973
Last 7 days vs normal
On average 3°2° colder than normal (daily mean temperature).
- −12°−7°SunOct 18
- −7°−4°MonOct 19
- −2°−1°TueOct 20
- +2°+1°WedOct 21
- —ThuOct 22
- +4°+2°FriOct 23
- —SatOct 24
Groton weather by month: normals, records, snow and freeze dates
Sun & moon
Sun
Sunrise 7:10 AM, sunset 5:53 PM.
- Daylight
- 10 h 44 min
- Losing 2 min 35 s a day; shortest Dec 21, 1 h 32 min less
- Golden hour
- 5:15–6:11 PM
- Morning 6:53–7:48 AM
- Blue hour
- 6:11–6:22 PM
- Morning 6:42–6:53 AM; first light 6:42 AM
Stars tonight? Good
Clear 1:21–6:42 AM; moon 96% lit, sets 5:20 AM.
Moon
Waxing gibbous
95% lit · growing
- Today
- sets 5:20 AM · rises 4:50 PM
- Full moon
- Oct 26
- New moon
- Nov 9
