Can you swim here today?
Groton Reservoir
Connecticut · Reservoir
Cool water — ease in carefully
Use cautionAs of August 21, 2026, the water temperature at Groton Reservoir is 69°F (21°C), measured by NOAA buoy NLHC3, 3 miles away.
Cool water — ease in carefully: water temperature is 69°F, cool enough to cause cold-water shock on a sudden entry.
- Water temperature is 69°F, cool enough to cause cold-water shock on a sudden entry. — NOAA buoy NLHC3, as of Aug 21, 7:30 PM UTC
- Heavy rain today can raise bacteria levels near outfalls and river mouths.
Water temp
69°F
21°C
No official beach-advisory feed for Connecticut yet — follow posted signs and local guidance.
Live data from NOAA buoy NLHC3 (3 mi away), as of Aug 21, 7:30 PM UTC.
Before you get in
- Never swim alone — and keep weaker swimmers within arm's reach.
- Scout depth and entry/exit points before you get in.
- Read the current: avoid fast, rising, or murky water.
- Check the forecast — get out well before storms or lightning.
- Obey posted signs, flags, and lifeguard guidance.
Read next
Conditions are for general information only and can change quickly. Always judge the water in person and follow posted advisories and local guidance before swimming or paddling.