Thousand Islands, NY

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Power House at Boldt Castle on Heart Island, Thousand Islands, New York

Today’s Forecast:

☁
37°F
High: 41° | Low: 31°
Current Temperature
Cloudy
Station: KGTB
Observed at: 12:55 pm CST on 11/13/26
Wind: 8 mph | Humidity: 65%
This Afternoon:Cloudy, with a high near 41. Northwest wind around 7 mph.
Tonight:A chance of snow showers after 3am. Cloudy, with a low around 31. Northwest wind around 6 mph. Chance of precipitation is 30%. Little or no snow accumulation expected.
Saturday:A chance of snow showers before 9am, then rain and snow showers likely. Cloudy, with a high near 42. Northwest wind 5 to 9 mph. Chance of precipitation is 60%. Little or no snow accumulation expected.
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Today’s Report:

⛵ Boating

  12 /100

Not Recommended for boating. High near 42°F. Rain forecast later today (60%). Light wind (9 mph). Temperatures outside comfort limits (42°F).

  • Temp: Unfavorable weather factor
  • Rain: Marginal weather factor
  • Wind: Favorable conditions
  • Thunderstorm: Favorable conditions
Tomorrow's Outlook:
Not Recommended 23/100
Not Recommended for boating. High near 44°F. Low rain risk (6%). Light wind (8 mph). Temperatures outside comfort limits (44°F).

🛶 Paddling

  12 /100

Not Recommended for paddling. High near 42°F. Rain forecast later today (60%). Light wind (9 mph). Temperatures outside comfort limits (42°F).

  • Temp: Unfavorable weather factor
  • Rain: Marginal weather factor
  • Wind: Favorable conditions
  • Thunderstorm: Favorable conditions
Tomorrow's Outlook:
Not Recommended 23/100
Not Recommended for paddling. High near 44°F. Low rain risk (6%). Light wind (8 mph). Temperatures outside comfort limits (44°F).

⛺ Camping

Use Caution
  41 /100

Use Caution for camping. High near 42°F. Rain forecast later today (60%). Light wind (9 mph).

  • Temp: Marginal weather factor
  • Rain: Marginal weather factor
  • Wind: Favorable conditions
  • Thunderstorm: Favorable conditions
Tomorrow's Outlook:
Good 80/100
Good for camping. High near 44°F. Low rain risk (6%). Light wind (8 mph).

🎪 Outdoor Events / Activities

  12 /100

Not Recommended for outdoor events / activities. High near 42°F. Rain forecast later today (60%). Light wind (9 mph). Temperatures outside comfort limits (42°F).

  • Temp: Unfavorable weather factor
  • Rain: Marginal weather factor
  • Wind: Favorable conditions
  • Thunderstorm: Favorable conditions
Tomorrow's Outlook:
Not Recommended 20/100
Not Recommended for outdoor events / activities. High near 44°F. Low rain risk (6%). Light wind (8 mph). Temperatures outside comfort limits (44°F).

About Thousand Islands

Thousand Islands is a New York destination for island-hopping, boating, paddling, campgrounds, and riverfront events.

Make the Most of a Thousand Islands Day

Match the route, launch, facility, or turnaround time to precipitation, wind, temperature, visibility, water conditions, snow or ice, and seasonal access. Keep a shorter or more sheltered alternative ready.

Weather Tips for Thousand Islands

  • Check official access notices, alerts, trail or road conditions, and local forecasts before leaving.
  • Check wind, waves, current, water temperature, ice reports, and lightning risk before launching or stepping onto frozen water; no forecast alone proves that ice is safe.
  • Bring layers, water, navigation, sun protection, and traction or flotation appropriate to the season and activity.
  • Allow extra time for traffic, limited winter daylight, lake-effect snow, freeze-thaw mud, and seasonal facility schedules.

Nearby Towns and Areas

This page can also be useful when planning outdoor time near:

  • Alexandria Bay
  • Clayton
  • Cape Vincent
  • Grindstone Island
  • Boldt Castle
  • St. Lawrence River

Plan Around the Conditions

Choose the safest version of a Thousand Islands day by matching the activity to current wind, precipitation, temperature, visibility, water or snow conditions, access, and daylight.

7-Day Forecast for Thousand Islands, NY

☁
37°F
High: 41° | Low: 31°
Current Temperature
Cloudy
Station: KGTB
Observed at: 12:55 pm CST on 11/13/26
Wind: 8 mph | Humidity: 65%
Fri ☁
41° 31°
1%
Sat ❄
42° 31°
60%
Sun ☁
44° 30°
6%
Mon ⛅
46° 31°
0%
Tue ⛅
51° 36°
0%
Wed ☀
53° 36°
0%
Thu ⛅
54° 38°
0%

7-Day High Temperature Trend

41° Fri 42° Sat 44° Sun 46° Mon 51° Tue 53° Wed 54° Thu

7-Day Low Temperature Trend

31° Fri 31° Sat 30° Sun 31° Mon 36° Tue 36° Wed 38° Thu

📊 7-Day Outdoor Outlook

Good Fair Poor 20 Fri 19 Sat 20 Sun 20 Mon 75 Tue 85 Wed 90 Thu
Forecast data from the National Weather Service  |  Last Updated: November 13, 2026 11:29 pm CST

Thousand Islands Weather by Season

Winter

Winter at Thousand Islands brings cold, shorter daylight, and periodic snow or ice. Cold water, wind, waves, and rapidly changing shore conditions remain serious hazards.

Spring

Spring is changeable, with rain, mud, snowmelt, rising water, and lingering ice in shaded or elevated terrain. Lower routes and developed facilities generally become usable before exposed, backcountry, or high-elevation areas.

Summer

Summer usually provides the broadest access, but heat, humidity, thunderstorms, crowds, and occasional wildfire smoke can alter plans. Start exposed outings early and keep a weather-safe turnaround point.

Fall

Fall brings cooler air, foliage crowds, shorter daylight, and increasing wind. Early snow or ice can reach northern and elevated areas while lower valleys and coastal destinations remain milder.

Key Climate Data Points

  • Annual average temperature: around 43–47°F, using the relevant local and elevation context.
  • Annual snowfall: commonly 55–90 inches, with wind and local lake-effect variation.
  • Warmest months: July and August are normally warmest.
  • Coolest months: January is typically coolest, with February similarly cold in northern and elevated areas.
  • Wettest season: precipitation is distributed through the year, with late spring through summer often wettest from rain and thunderstorms.
  • Driest season: no season is reliably dry statewide; early fall often provides the most stable outdoor windows.
  • Best outdoor window: June through October for warm-season access, with midwinter best only where established winter recreation is supported.