Skip to content
seatemperatures.net

Warmest sea in United States in May

4,477 coastal locations in United States ranked by their typical May sea temperature. Region-wide average in May: 16.4°C. The top of the list is where to find the warmest swimming this month.

Warmest in May

Howland Island

28.5°C May mean in United States

Regional May average

16.4°C

across all 4,477 coastal locations in United States

Vs annual mean

+0.2°C

above the year-round regional average

What the United States sea feels like in May

At this temperature, water will feel cold compared to a swimming pool, but with a bit of experience and practice most people will find the water relatively comfortable to swim in.

United States monthly average 10.0°C to 22.6°C
J
F
M
A
M
J
J
A
S
O
N
D
  • Warmest month August 22.6°C
  • Coldest month February 10.0°C
  • Annual mean 16.2°C
  • Months above 20°C 3 of 12

Where May fits in the year

May sits inside the regional pattern shown on the left. Pick a different month to see how the ranking shifts.

All twelve United States month rankings:

United States sea temperature map (live)

The map shows today's latest reading at every United States location. The list below is based on the typical May mean, useful for trip planning weeks or months ahead.

Zoom in to see individual locations. Click a pin for water temperatures. View list →
°C -2 0 1 3 5 7 9 11 13 15 17 19 21 24 27 30 35

Top 50 warmest United States locations in May

Sorted by the typical May mean built from a decade of daily readings at each location. Click any place for its 30-day chart, monthly profile, and full 10-year history.

# Location May mean
1 Howland Island Minor Outlying Islands 28.5°C
2 Lostmans River entrance, Florida Florida 28.4°C
3 Onion Key Bay Florida 28.4°C
4 Onion Key, Lostmans River, Florida Florida 28.4°C
5 Shark River entrance, Florida Florida 28.4°C
6 Cape Sable, East Cape, Florida Florida 28.4°C
7 Flamingo, Florida Bay, Florida Florida 28.4°C
8 Crane Keys, north side, Florida Bay, Florida Florida 28.2°C
9 Tavernier Creek, Hwy. 1 bridge, Hawk Channel, Florida Florida 28.2°C
10 East Bahia Honda Key, south end, Florida Bay, Florida Florida 28.2°C
11 Channel Five, east side, Hawk Channel, Florida Florida 28.2°C
12 Channel Five, west side, Hawk Channel, Florida Florida 28.2°C
13 Channel Two, west side, Hawk Channel, Florida Florida 28.2°C
14 Conch Key, eastern end, Florida Florida 28.2°C
15 Duck Key, Hawk Channel, Florida Florida 28.2°C
16 Grassy Key, north side, Florida Bay, Florida Florida 28.2°C
17 Grassy Key, south side, Hawk Channel, Florida Florida 28.2°C
18 Grassy Key Florida 28.2°C
19 Jewfish Hole, Long Key, Florida Bay, Florida Florida 28.2°C
20 Long Key Bight, Long Key, Florida Florida 28.2°C
21 Long Key Lake, Long Key, Florida Florida 28.2°C
22 Long Key, western end, Florida Florida 28.2°C
23 Toms Harbor Channel, Hwy. 1 bridge, Florida Florida 28.2°C
24 Toms Harbor Cut, Florida Florida 28.2°C
25 Palmyra Island Northern Line Islands 28.1°C
Show 25 more ▸
26 Annette Key, north end, Big Spanish Channel, Florida Florida 28.1°C
27 Big Spanish Key, Florida Florida 28.1°C
28 Content Keys, Content Passage, Florida Florida 28.1°C
29 Crawl Key, Big Spanish Channel, Florida Florida 28.1°C
30 Horseshoe Keys, south end, Florida Florida 28.1°C
31 Howe Key, northwest end, Florida Florida 28.1°C
32 Johnson Keys, north end, Florida Florida 28.1°C
33 Little Pine Key, north end, Florida Florida 28.1°C
34 Little Spanish Key, Spanish Banks, Florida Florida 28.1°C
35 West Bahia Honda Key, Florida Florida 28.1°C
36 Chatham River entrance, Florida Florida 28.1°C
37 Indian Key, Florida Florida 28.1°C
38 Pavilion Key Florida 28.1°C
39 Alligator Reef Florida 28.1°C
40 Channel Two, east, Lower Matecumbe Key, Fla. Bay, Florida Florida 28.1°C
41 East Key, southern end, Florida Bay, Florida Florida 28.1°C
42 Indian Key Anchorage, Lower Matecumbe Key, Florida Florida 28.1°C
43 Indian Key, Hawk Channel, Florida Florida 28.1°C
44 Lignumvitae Key, NE side, Florida Bay, Florida Florida 28.1°C
45 Lignumvitae Key, west side, Florida Bay, Florida Florida 28.1°C
46 Little Basin, Upper Matecumbe Key, Florida Bay, Florida Florida 28.1°C
47 Matecumbe Bight, Lower Matecumbe Key, Fla. Bay, Florida Florida 28.1°C
48 Matecumbe Harbor, Lower Matecumbe Key, Fla. Bay, Florida Florida 28.1°C
49 Plantation Key, Hawk Channel, Florida Florida 28.1°C
50 Shell Key Channel, Florida Bay, Florida Florida 28.1°C

Coldest 10 in United States in May

Same data the other way. Helpful if you want to know which United States coasts to avoid for swimming in May.

# Location May mean
1 Cape Espenberg, Kotzebue Sound Alaska -1.7°C
2 Cape Krusenstern, Kotzebue Sound Alaska -1.6°C
3 Kivalina Alaska -1.6°C
4 Red Dog Dock Alaska -1.6°C
5 Shishmaref Inlet 2 Alaska -1.6°C
6 Kotzebue, Kotzebue Sound Alaska -1.6°C
7 Goodhope Bay, Kotzebue Sound Alaska -1.6°C
8 Barrow (offshore) Alaska -1.5°C
9 Deering, Kotzebue Sound Alaska -1.5°C
10 Flaxman Island Alaska -1.5°C

More on this region