Weather in Miami in August

Shoulder season. August sits in between. You will get good days and you will lose some. You should expect rain on 27 days of the month, which is more days wet than dry.

August ranks 12 of 12 — near the bottom of Miami's year. January is the month that works, and the swing between the two is 35 points, which is a different holiday rather than a slightly better one.

Rain on 27 of the month's 31 days, 4 of them heavy. At that frequency a wet-weather backup is not a contingency, it is the itinerary — book the indoor things first and treat the clear days as the bonus. Pack for 30 °C days and 28.2 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 15 days top 30 °C — hot spells arrive, but they break; the day barely swings — 1.8 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest August day reached 31.7 °C and the coldest night fell to 26 °C, and the wettest single day dropped 60 mm — roughly 33% of the month's rain in one day.

August is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest August on record still delivered 270 mm against 90 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 182 mm average is a reasonable planning figure, not a promise.

Wind is light at 11.8 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, high enough to notice on the warm days without dominating them.

How August sits in the year

Temperatures hold steady either side: 29.7 °C in July, 30 here, 29.3 in September. Nothing about the timing within the month matters much.

Daylight in August

August is at or near the longest days of Miami's year: 13.1 hours of daylight, losing 0.6 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 29.7 °C in August — warm enough that the water offers no relief from the heat. This is the warmest the water gets all year.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

August in Miami versus nearby

If Miami is one option among several, the nearby comparison is worth making. Cape Coral is close enough to be a coin toss — within a degree on temperature, 2 days more rain. Key West is close enough to be a coin toss — within a degree on temperature, 1 day less rain.

So: August is a compromise. January is 35 points better and is what Miami is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Miami

See all twelve months in Miami, or where else to go in August.