What is the average water temperature in New Hampshire?

The current average water temperature across New Hampshire's monitored water bodies is 58.3°F.

🌡️

New Hampshire Water Temperatures

Q: What is the warmest lake in New Hampshire today?

Ashuelot River Near Gilsum, Nh at 66.2°F.

Current lake & river temperatures in New Hampshire — updated daily from USGS sensors.

With Data

58.3°F

State Avg

66.2°F

Warmest

66.2°F

Warmest

Ashuelot River Near Gilsum, Nh

58.3°F

State Average

62 water bodies

51.1°F

Coldest

Smith River Near Bristol, Nh

🏊

Swimming Conditions

🚫 Too cold for most swimmers

Based on avg 58.3°F

🎣

Fishing Conditions

🎣 Good — trout, walleye, bass

Based on avg 58.3°F

New Hampshire — Ranked by Temperature

10 with data

#	Water Body	°F	°C	Condition	🏊	Date
1	Ashuelot River Near Gilsum, Nh River	66.2°	19°	🌤️ Comfortable	⚠️ Brisk	Jun 4
2	South Branch Piscataquog River Near Goffstown, Nh River	63°	17.2°	🌊 Cool	🚫 Cold	Sep 30
3	Connecticut R Below Indian Stream Nr Pittsburg, Nh River	62.8°	17.1°	🌊 Cool	🚫 Cold	Sep 30
4	Connecticut River At North Stratford, Nh River	60.3°	15.7°	🌊 Cool	🚫 Cold	Jun 4
5	Isinglass R At Rochester Neck Rd, Nr Dover, Nh Lake	57.4°	14.1°	🌊 Cool	🚫 Cold	Sep 30
6	Lamprey River At Langford Road, At Raymond, Nh River	56.3°	13.5°	🌊 Cool	🚫 Cold	Sep 30
7	Souhegan River (Site Wlr-1) Near Milford, Nh River	56.1°	13.4°	🌊 Cool	🚫 Cold	Sep 30
8	Cold River At High Street, At Alstead, Nh River	55.2°	12.9°	🌊 Cool	🚫 Cold	Sep 30
9	Saco River At River Street, At Bartlett, Nh River	54.5°	12.5°	❄️ Cold	⛔ Very cold	Jun 4
10	Smith River Near Bristol, Nh River	51.1°	10.6°	❄️ Cold	⛔ Very cold	Oct 16
11	Androscoggin River Near Gorham, Nh River	—	—	—	—	—
12	Pemigewasset River At Plymouth, Nh River	—	—	—	—	—
13	Contoocook R Bl Hopkinton Dam At W Hopkinton, Nh Reservoir	—	—	—	—	—
14	Merrimack R Nr Goffs Falls, Below Manchester, Nh Lake	—	—	—	—	—
15	Upper Ammonoosuc River Near Groveton, Nh River	—	—	—	—	—
16	Mascoma River At Mascoma, Nh River	—	—	—	—	—
17	Diamond River Near Wentworth Location, Nh River	—	—	—	—	—
18	Cocheco River Near Rochester, Nh River	—	—	—	—	—
19	East Branch Pemigewasset River At Lincoln, Nh River	—	—	—	—	—
20	Contoocook River At Peterborough, Nh River	—	—	—	—	—
21	Piscataquog River Bl Everett Dam, Nr E Weare, Nh River	—	—	—	—	—
22	Spicket River Near Methuen, Ma River	—	—	—	—	—
23	Sugar River 0.2 Mi Below Nh 11, At Sunapee, Nh River	—	—	—	—	—
24	Ashuelot River At West Swanzey, Nh River	—	—	—	—	—
25	Exeter River At Odell Road, Near Sandown, Nh River	—	—	—	—	—
26	Blackwater River Near Webster, Nh River	—	—	—	—	—
27	Souhegan River At Merrimack, Nh River	—	—	—	—	—
28	Ammonoosuc River At Bethlehem Junction, Nh River	—	—	—	—	—
29	Ashuelot River Below Surry Mt Dam, Near Keene, Nh River	—	—	—	—	—
30	Androscoggin River Below Bog Brook At Cambridge Nh River	—	—	—	—	—
31	Oyster River Near Durham, Nh River	—	—	—	—	—
32	Baker River Near Rumney, Nh River	—	—	—	—	—
33	Contoocook River Near Henniker, Nh River	—	—	—	—	—
34	Piscataquog River Near Goffstown, Nh River	—	—	—	—	—
35	Connecticut River At North Walpole, Nh River	—	—	—	—	—
36	Mascoma River At West Canaan, Nh River	—	—	—	—	—
37	Lake Winnipesaukee At Weirs Beach, Nh Lake	—	—	—	—	—
38	Bearcamp River At South Tamworth, Nh River	—	—	—	—	—
39	Winnicut River At Greenland, Nr Portsmouth, Nh River	—	—	—	—	—
40	Merrimack River At Franklin Junction, Nh River	—	—	—	—	—
41	Suncook River At Nh 28, Near Suncook, Nh River	—	—	—	—	—
42	Spicket River At North Salem, Nh River	—	—	—	—	—
43	Connecticut River At West Lebanon, Nh River	—	—	—	—	—
44	Otter Brook Below Otter Brook Dam, Near Keene, Nh River	—	—	—	—	—
45	Peabody River At Gorham, New Hampshire River	—	—	—	—	—
46	Lamprey River Near Newmarket, Nh River	—	—	—	—	—
47	Cockermouth River Below Hardy Brook, At Groton, Nh River	—	—	—	—	—
48	Warner River At Davisville, Nh River	—	—	—	—	—
49	Connecticut River Near Dalton, Nh River	—	—	—	—	—
50	Androscoggin River At Errol, Nh River	—	—	—	—	—
51	Pemigewasset River At Woodstock, Nh River	—	—	—	—	—
52	Nubanusit Bk Blw Macdowell Dam Nr Peterborough Nh Reservoir	—	—	—	—	—
53	Sugar River At West Claremont, Nh River	—	—	—	—	—
54	Ashuelot River At Hinsdale, Nh River	—	—	—	—	—
55	Pawtuckaway Lake Near Nottingham, Nh Lake	—	—	—	—	—
56	Saco River Near Conway, Nh River	—	—	—	—	—
57	Exeter River At Haigh Road, Near Brentwood, Nh River	—	—	—	—	—
58	Winnipesaukee River At Tilton, Nh River	—	—	—	—	—
59	Suncook River At North Chichester, Nh River	—	—	—	—	—
60	Beaver Brook At North Pelham, Nh River	—	—	—	—	—
61	Ammonoosuc River Below Lisbon Dam, At Lisbon, Nh River	—	—	—	—	—
62	Ashuelot River Above The Branch, At Keene, Nh River	—	—	—	—	—

Ashuelot River Near Gilsum, Nh River

66.2°F

🌤️ Comfortable

South Branch Piscataquog River Near Goffstown, Nh River

63°F

🌊 Cool

Connecticut R Below Indian Stream Nr Pittsburg, Nh River

62.8°F

🌊 Cool

Connecticut River At North Stratford, Nh River

60.3°F

🌊 Cool

Isinglass R At Rochester Neck Rd, Nr Dover, Nh Lake

57.4°F

🌊 Cool

Lamprey River At Langford Road, At Raymond, Nh River

56.3°F

🌊 Cool

Souhegan River (Site Wlr-1) Near Milford, Nh River

56.1°F

🌊 Cool

Cold River At High Street, At Alstead, Nh River

55.2°F

🌊 Cool

Saco River At River Street, At Bartlett, Nh River

54.5°F

❄️ Cold

Smith River Near Bristol, Nh River

51.1°F

❄️ Cold

Androscoggin River Near Gorham, Nh River

—

Pemigewasset River At Plymouth, Nh River

—

Contoocook R Bl Hopkinton Dam At W Hopkinton, Nh Reservoir

—

Merrimack R Nr Goffs Falls, Below Manchester, Nh Lake

—

Upper Ammonoosuc River Near Groveton, Nh River

—

Mascoma River At Mascoma, Nh River

—

Diamond River Near Wentworth Location, Nh River

—

Cocheco River Near Rochester, Nh River

—

East Branch Pemigewasset River At Lincoln, Nh River

—

Contoocook River At Peterborough, Nh River

—

More New Hampshire Resources

🗺️ New Hampshire Water Levels 🎣 Weekly Fishing Report ⛵ Boat Ramp Status 🌵 Drought Conditions 🌡️ All States

❓ New Hampshire Water Temperature FAQ

What is the warmest lake in New Hampshire today?

Based on our latest USGS data, Ashuelot River Near Gilsum, Nh is currently the warmest water body in New Hampshire at 66.2°F.

Which New Hampshire lakes are good for swimming right now?

Lakes with water temperatures above 72°F are generally comfortable for swimming. Currently, New Hampshire's average water temperature is 58.3°F — check individual lakes above for specific conditions.

What is the best water temperature for fishing in New Hampshire?

The optimal temperature range depends on your target species. For bass fishing, look for water bodies between 65–75°F. For trout, target the coldest water bodies in New Hampshire — typically 50–65°F. Use the table above to identify which lakes are in the ideal range for your target species.

🔬 Data Methodology & Sources

Water temperature readings on this site are collected from USGS (United States Geological Survey) monitoring stations installed at lakes, rivers, and reservoirs across the country. Sensors measure water surface temperature in Celsius, which is converted to Fahrenheit for display. Data is retrieved and stored daily. Temperatures shown reflect the most recent available sensor reading for each water body, typically from the past 1–30 days depending on station reporting frequency.

⚠️ Water temperatures can vary significantly across a water body due to depth, currents, and time of day. Sensor readings represent conditions at the monitoring station location. Always exercise caution when swimming and consult local authorities for official safety advisories.