Match the wetsuit to the coldest water you'll surf: a 1.5mm wetsuit top or springsuit at 68°F and up, a 3/2mm fullsuit from 57°F to 68°F, a 4/3mm with boots from 52°F to 57°F, and a 5/4mm or thicker with a hood, boots and gloves under 52°F. Using NOAA's monthly averages, that means a 3/2mm year-round in Southern California, a top in Hawaii and South Florida, and the full range on the East Coast.
We're a wetsuit brand from Sydney, Australia, so we think in Celsius and we call a full wetsuit a “steamer”. For this guide we've done the conversion for you. The temperatures below are NOAA's long-run monthly averages at coastal stations, and the thickness bands are the same ones we use at home.
What thickness wetsuit do I need for my water temperature?
| Water temperature | What to wear |
|---|---|
| 68°F and up (20°C) | 1.5mm wetsuit top or springsuit |
| 57°F to 68°F (14°C to 20°C) | 3/2mm fullsuit |
| 52°F to 57°F (11°C to 14°C) | 4/3mm fullsuit with boots |
| Under 52°F (under 11°C) | 5/4mm or thicker, with a hood, boots and gloves |
Pick for the coldest session you'll actually paddle out for, not the best day of the month. If you run cold, going one step up is fine.
What wetsuit do I need on each US coast?
| Region | NOAA station(s) | Coldest month | Warmest month | What to wear |
|---|---|---|---|---|
| Southern California | San Diego Bay, La Jolla, Santa Monica | 58.4°F (Jan, Santa Monica) | 72.1°F (Aug, San Diego Bay) | 3/2mm fullsuit year-round; 1.5mm top on warm late-summer days |
| Central California | Monterey, San Francisco | 52.5°F (Jan, San Francisco) | 61.5°F (Sep, San Francisco) | 4/3mm with boots in winter; 3/2mm from about July to October |
| Northern California to Washington | Crescent City, Westport WA | 47.1°F (Jan, Westport) | 58.9°F (Aug, Crescent City) | 5/4mm hooded with boots and gloves in winter; 4/3mm most of the rest; 3/2mm only at the late-summer peak |
| Hawaii | Honolulu | 76.7°F (Feb) | 81.7°F (Sep) | 1.5mm top or springsuit at most |
| Southeast Florida | Lake Worth Pier | 74.5°F (Jan) | 85.7°F (Aug) | 1.5mm top at most |
| Northeast Florida | Mayport | 58.3°F (Jan and Feb) | 83.4°F (Aug) | 3/2mm December to March; top from April |
| Gulf Coast | Pensacola, Galveston (North Jetty) | 55.8°F (Jan, Galveston) | 86.8°F (Aug, Galveston) | 3/2mm November to March, 4/3mm if January bites; top from April |
| Outer Banks | Duck NC | 43.4°F (Feb) | 75.0°F (Sep) | 5/4mm hooded January to March; 3/2mm May, June and November; top July to October |
| New Jersey and Long Island | Atlantic City, Montauk | 37.4°F (Feb, Montauk) | 72.9°F (Aug, Atlantic City) | 5/4mm hooded in winter; 3/2mm June and October; top July to September |
| New England | Newport RI, Portland ME | 37.6°F (Feb, Portland) | 70.0°F (Aug, Newport) | 5/4mm hooded December to April; 3/2mm in summer |
Southern California: a 3/2mm all year
San Diego Bay averages 59.2°F in January and 72.1°F in August. La Jolla runs from 58.9°F in January and February to 68.4°F in August, and Santa Monica from 58.4°F in January to 68.4°F in August. That sits inside the 3/2mm band nearly every month. In August and September a 1.5mm top works on warm, windless days.
Central and Northern California, Oregon and Washington: think thicker
Monterey averages 54.8°F in January and peaks at 59.6°F in August and September. San Francisco runs from 52.5°F in January to 61.5°F in September. That's 4/3mm water in winter, with a 3/2mm workable from about July to October.
Further north it's colder again. Crescent City averages 51.2°F in January and February, and Westport, Washington, 47.1°F in January, with neither getting much past 58°F in late summer. Plan on a 5/4mm with a hood, boots and gloves in winter and a 4/3mm most of the rest of the year. July to September averages (57.1°F to 58.9°F) only just reach the 3/2mm band.
Hawaii and South Florida: a top at most
Honolulu averages 76.7°F in February, its coolest month, and 81.7°F in September. Lake Worth Pier in Palm Beach County runs from 74.5°F in January to 85.7°F in August. A 1.5mm top or springsuit is for early, windy or long sessions; plenty of days need nothing but boardshorts.
Northeast Florida and the Gulf Coast: a 3/2mm for winter
Mayport, near Jacksonville, averages 58.3°F in January and February and 83.4°F in August, so a 3/2mm covers December to March and a top takes over from April. On the Gulf, Pensacola averages 56.9°F and Galveston's North Jetty 55.8°F in January, just under the 3/2mm band, so a 4/3mm is worth it that month if you feel the cold. November, February and March are 3/2mm water at both, and from April the averages are top weather.
The Outer Banks: every thickness in one year
Duck, North Carolina, swings from 43.4°F in February to 75.0°F in September. January to March averages are under 47°F, which is 5/4mm-and-hood territory. April (52.3°F) and December (52.1°F) are 4/3mm months, May, June and November suit a 3/2mm, and July to October averages run from 68.7°F to 75.0°F, which is top weather.
New Jersey, New York and New England: summer is short
Atlantic City averages 38.4°F in February and 72.9°F in August, and Montauk 37.4°F in February and 71.2°F in August. Both suit a top from July to September and a 3/2mm in June and October, with a 4/3mm in May and November and a hooded 5/4mm through winter.
Newport, Rhode Island, peaks at 70.0°F in August, so a top only works in July and August there. Portland, Maine, never averages more than 61.3°F, so a 3/2mm is as light as it gets, from July to September. From December to April both average under 46°F.
Which Flatrock wetsuit fits US water?
We make two styles, built for the two warmer bands. Our 3/2mm chest zip fullsuit (V3) is made for 57°F to 68°F water, with thermal lining from chest to knee and short and tall sizes. Our 1.5mm long sleeve wetsuit top (V2) is for 68°F and up. We don't make a 4/3mm or 5/4mm yet, so for winter in the Northeast or the Pacific Northwest you'll want something thicker than ours. Standard shipping to the US is free and takes 7 to 10 business days from Sydney.
Water temperatures are monthly averages from the NOAA National Centers for Environmental Information Coastal Water Temperature Guide. NOAA retired the guide in May 2025 but still publishes its data. The stations are tide gauges at or near the coast, some in bays and harbors, so the open-ocean surf on a given day can run a few degrees either way. Check a live reading before you go.
FAQs
What wetsuit do I need for 60°F water?
A 3/2mm fullsuit. On our chart a 3/2mm covers water from 57°F to 68°F, which takes in Southern California for most of the year.
What wetsuit do I need for Southern California?
A 3/2mm fullsuit covers it year-round. NOAA's monthly averages at San Diego Bay, La Jolla and Santa Monica stay between about 58°F and 72°F, and late summer is warm enough for a 1.5mm wetsuit top on some days.
Do I need a wetsuit in Hawaii?
Usually not much of one. Honolulu's monthly averages run from 76.7°F in February to 81.7°F in September, so a 1.5mm top or springsuit is the most you'd want, and plenty of surfers wear boardshorts.
When can you surf New Jersey in a 3/2mm?
Roughly June and October. Atlantic City averages 64.6°F in June and 64.2°F in October. July to September averages 68.9°F to 72.9°F, which is wetsuit-top water, and winter drops below 40°F.
