Miami Beach water temperature by month
Swimmable year-round.
Month by month
| Month | Typical | Feels |
|---|---|---|
| January | 72° | perfect |
| February | 75° | perfect |
| March | 76° | perfect |
| April | 79° | perfect |
| May | 84° | bath-warm |
| June | 86° | bath-warm |
| July | 88° | bath-warm |
| August | 88° | bath-warm |
| September | 87° | bath-warm |
| October | 82° | bath-warm |
| November | 78° | perfect |
| December | 75° | perfect |
The year at a glance
The water right now
Typically about 82° in October — bath-warm.
from the Virginia Key station, about 5 miles away
bath-warm
The Atlantic here almost never leaves the swimmable range, even in January. It turns bath-warm around May and stays there past Halloween.
Seaweed season
On Florida's southeast coast and the Keys, sargassum season runs from April through August, heaviest from June through July.
USF's bulletins treat the Keys and the southeast coast together, and in an ordinary year report them largely clear until late April or May. North of Cape Canaveral the bulletins say nothing either way, so neither do we.
- January: rare
- February: rare
- March: rare
- April: some seaweed
- May: some seaweed
- June: peak season
- July: peak season
- August: some seaweed
- September: rare
- October: rare
- November: rare
- December: rare
This is a pattern, not a forecast. The lab that watches this says plainly that predicting seaweed on an individual beach is difficult or impossible — whether it comes ashore depends on winds, tides and currents nobody can call ahead. The bulletins track how much is out there and look about a month on.
From the Sargassum Watch System, the Optical Oceanography Lab at the USF College of Marine Science. Read the current bulletin for this month's outlook.
Jellyfish and sea lice
What usually turns up on Florida's Atlantic coast, and when.
- Stings follow the heat. Palm Beach County says jellyfish are usually more prominent in the warmer summer months. Palm Beach County's parks department — sea creatures and beach hazards
- The Park Service says the same thing on the Space Coast — during summer months the warm water causes jellyfish and man-o-war to multiply — and adds that they travel with the currents, so they come and go seasonally. the National Park Service — safety at Canaveral National Seashore
- In northeast Florida the two you are most likely to find on the sand are the moon jelly and the cannonball jellyfish, both most abundant during the summer season. the National Park Service — jellyfish at Fort Matanzas
- The Portuguese man o’ war runs the other way round: the county puts it on this coast predominately during the months of November through April. Palm Beach County's parks department — sea creatures and beach hazards
- Sea lice is not lice. It is miniature jellyfish larvae caught under bathing suits, t-shirts and even hair, which is why the rash turns up where the suit was; the itch starts hours after you get out and usually lasts two to four days. Palm Beach County's parks department — sea creatures and beach hazards
- The larva behind it is most likely the thimble jellyfish: its eggs hatch into a drifting larva called a planula, and it is that, rather than the grown animal, which seems to be the source of the problem. UF/IFAS Extension — They call it "sea lice"
This is what a season usually looks like, not a forecast of any particular week. Jellyfish drift on wind and current, so the people who watch them say there are tendencies but no guarantees — the lifeguard flags on the day beat any calendar.
About this reading
The Virginia Key station sits in an inlet; surf-zone water can run a few degrees off this reading.
Reading from the Virginia Key station, about 5 miles away.
Warm water says nothing about surf, rip currents, or bacteria — check local lifeguard flags and advisories.