Updated 2 Nov 2026 · recomputed nightly
Is September 2027 a good month to visit Key West?
Calm — September is Key West's quietest month: the typical day is calmer than 96% of its year.
The weather is the trade-off here, not the crowds.
Calm · Lively · Busy · Packed rank a day against Key West's own year — not a headcount.
September is Key West with the crowds gone — Calm on 19 of 30 days and never busier than Lively, hot and wet, around 29°C / 85°F with rain on about 19 days.
Yes, if the weather does not put you off. September in Key West is Calm on the typical day, and not one of the 30 days in our window is crowded enough to call Busy. Expect around 29 °C by day, with rain on about 19 days. Public holidays in United States add to it. Cruise ships call on 13 of the 30 days. Late September is the month's quietest stretch in Key West — the typical day at 4%, against 15% in early September. The crush is at Mallory Square at sunset; the quiet is at the old town's back lanes. The calmest day is Wednesday 1 September, the busiest Monday 13 September.
In short, quiet and wide open, if the weather doesn't put you off.
Of the 12 months we forecast for Key West, September is the quietest. Its heaviest day is Mon 13 Sep, busier than 60% of the year; its lightest is Wed 1 Sep at 4%.
You won't need skip-the-line tickets here — that's rather the point. A month like this is the one for the longer visit — the guided walk, the food tour, the day out of town, with room and time to enjoy them. see what's on →
Pack for wet first — rain on 19 of 30 days.
A folding one lives in the day bag and weighs nothing.
See umbrellas →
Refilling costs nothing and saves the walk to find a shop.
See water bottles →
How busy is Key West in September?
It's quiet right through September — no crowded stretch to plan around.
Cruise ships are in port on 13 of 30 days; the heaviest is Mon 13 Sep, 1 ship in at once. Those mornings fill the squares first — start early, or save them for indoors.
The month is not one thing: its lightest day sits at 4% of the year and its heaviest at 60%, so where you land inside it matters. Daylight runs about 12 hours.
Any day works. There is no need to plan your dates around the crowds.
Wed 01 Sep Calm busier than 4% of days here
Record Key West on Wed 1 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-01 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Thu 02 Sep Calm busier than 4% of days here
Record Key West on Thu 2 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-02 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Fri 03 Sep Calm busier than 26% of days here · ⚓1
- Margaritaville At Sea Paradise — guest capacity 1,308 10:00–18:00
Record Key West on Fri 3 Sep 2027 is forecast Calm. 1 cruise ship scheduled, at least 1,308 guests at double occupancy; ships in port 10:00–18:00. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-03 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sat 04 Sep Calm busier than 4% of days here
Record Key West on Sat 4 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-04 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sun 05 Sep Lively busier than 40% of days here · ⚓1
- Margaritaville At Sea Islander — guest capacity 2,210 13:00–19:00
Record Key West on Sun 5 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,210 guests at double occupancy; ships in port 13:00–19:00. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-05 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Mon 06 Sep Lively busier than 45% of days here · ⚓1 · United States public holiday
- Margaritaville At Sea Beachcomber — guest capacity 2,698
Record Key West on Mon 6 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,698 guests at double occupancy. Why: United States public holiday. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-06 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Tue 07 Sep Calm busier than 4% of days here
Record Key West on Tue 7 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-07 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Wed 08 Sep Calm busier than 4% of days here
Record Key West on Wed 8 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-08 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Thu 09 Sep Lively busier than 40% of days here · ⚓1
- Jewel Of The Seas — guest capacity 2,144
Record Key West on Thu 9 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,144 guests at double occupancy. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-09 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Fri 10 Sep Lively busier than 44% of days here · ⚓1
- Valiant Lady — guest capacity 2,770 08:00–17:00
Record Key West on Fri 10 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,770 guests at double occupancy; ships in port 08:00–17:00. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-10 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sat 11 Sep Calm busier than 4% of days here
Record Key West on Sat 11 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-11 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sun 12 Sep Calm busier than 4% of days here
Record Key West on Sun 12 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-12 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Mon 13 Sep Lively busier than 60% of days here · ⚓1
- Carnival Breeze — guest capacity 3,690 10:00–18:00
Record Key West on Mon 13 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 3,690 guests at double occupancy; ships in port 10:00–18:00. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-13 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Tue 14 Sep Lively busier than 42% of days here · ⚓1
- Margaritaville At Sea Beachcomber — guest capacity 2,698
Record Key West on Tue 14 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,698 guests at double occupancy. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-14 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Wed 15 Sep Calm busier than 26% of days here · ⚓1
- Margaritaville At Sea Paradise — guest capacity 1,308 07:00–16:00
Record Key West on Wed 15 Sep 2027 is forecast Calm. 1 cruise ship scheduled, at least 1,308 guests at double occupancy; ships in port 07:00–16:00. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-15 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Thu 16 Sep Calm busier than 4% of days here
Record Key West on Thu 16 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-16 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Fri 17 Sep Lively busier than 47% of days here · ⚓1
- Celebrity Reflection — guest capacity 3,046 08:00–17:00
Record Key West on Fri 17 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 3,046 guests at double occupancy; ships in port 08:00–17:00. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-17 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sat 18 Sep Calm busier than 4% of days here
Record Key West on Sat 18 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-18 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sun 19 Sep Lively busier than 42% of days here · ⚓1
- Margaritaville At Sea Beachcomber — guest capacity 2,698 07:00–15:00
Record Key West on Sun 19 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,698 guests at double occupancy; ships in port 07:00–15:00. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-19 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Mon 20 Sep Calm busier than 4% of days here
Record Key West on Mon 20 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-20 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Tue 21 Sep Calm busier than 4% of days here
Record Key West on Tue 21 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-21 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Wed 22 Sep Calm busier than 4% of days here
Record Key West on Wed 22 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-22 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Thu 23 Sep Lively busier than 40% of days here · ⚓1
- Jewel Of The Seas — guest capacity 2,144
Record Key West on Thu 23 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,144 guests at double occupancy. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-23 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Fri 24 Sep Lively busier than 44% of days here · ⚓1
- Valiant Lady — guest capacity 2,770 08:00–17:00
Record Key West on Fri 24 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 2,770 guests at double occupancy; ships in port 08:00–17:00. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-24 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sat 25 Sep Calm busier than 4% of days here
Record Key West on Sat 25 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-25 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Sun 26 Sep Calm busier than 4% of days here
Record Key West on Sun 26 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-26 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Mon 27 Sep Lively busier than 47% of days here · ⚓1
- Celebrity Reflection — guest capacity 3,046 08:00–17:00
Record Key West on Mon 27 Sep 2027 is forecast Lively. 1 cruise ship scheduled, at least 3,046 guests at double occupancy; ships in port 08:00–17:00. The day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-27 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Tue 28 Sep Calm busier than 4% of days here
Record Key West on Tue 28 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-28 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Wed 29 Sep Calm busier than 4% of days here
Record Key West on Wed 29 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-29 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Thu 30 Sep Calm busier than 4% of days here
Record Key West on Thu 30 Sep 2027 is forecast Calm. This quiet day in full, the year at a glance, and how this day compares: https://avoid-crowds.com/key-west-florida/#d-2027-09-30 (Avoid-Crowds, as of 2 Nov 2026; recomputed nightly.)
Which week of September is quietest in Key West?
Late September is the month's quietest stretch in Key West — the typical day at 4%, against 15% in early September.
The upside of a quiet September
- Walk straight into the sights that sell out in high season — no timed ticket, no queue.
- This is a wing-it month: nothing needs locking in.
- Photograph the landmarks empty — the shot everyone else queues for.
No queues to skip, and nothing to book ahead — that's the whole point.
September weather in Key West
Real heat — around 29°C / 85°F by day, so pace the afternoons and carry water, with rain on about 19 days, so keep a layer handy.
This is the value month: no need to book far ahead, and the freedom to change plans on the day is part of what you're getting.
More about Key West in September
Based on: United States' public holidays · the official airport-arrivals pattern (BTS T-100, measured 2023–2025; airport-arrivals proxy for visitor volume, biased low for drive-in visitors) · five years of weather records (2019–2023) · confirmed event dates · the published cruise schedule
Every figure is recomputed nightly from real cruise schedules, public and school holidays, and long-run climate normals. Gaps are shown, not filled.
