Key West, FL: average weather by month
NOAA 1991–2020 climate normals at the KEY WEST INTL AIRPORT station, read through NOAA's Regional Climate Centers' ACIS service. Every column below is the station's own average for that month over that 30-year period — not a forecast. The rainfall figures are NOAA's precipitation normal, so they count rain plus melted snow (and any other frozen precipitation, as water), not rain alone.
83.7°F
74°F
40.4 in
All 12 months
| Month | Avg. high | Avg. low | Rainfall |
|---|---|---|---|
| January | 75.8°F (24°C) | 65.5°F (19°C) | 1.83 in (46 mm) |
| February | 77.4°F (25°C) | 67.1°F (19°C) | 1.54 in (39 mm) |
| March | 79.6°F (26°C) | 69.3°F (21°C) | 1.53 in (39 mm) |
| April | 82.6°F (28°C) | 73.1°F (23°C) | 2.07 in (53 mm) |
| May | 85.9°F (30°C) | 76.4°F (25°C) | 3.12 in (79 mm) |
| June | 88.7°F (32°C) | 79.4°F (26°C) | 4.23 in (107 mm) |
| July | 90.2°F (32°C) | 80.6°F (27°C) | 3.63 in (92 mm) |
| August | 90.6°F (33°C) | 80.5°F (27°C) | 5.37 in (136 mm) |
| September | 89°F (32°C) | 79.2°F (26°C) | 7.24 in (184 mm) |
| October | 85.8°F (30°C) | 76.8°F (25°C) | 5.67 in (144 mm) |
| November | 81°F (27°C) | 72.2°F (22°C) | 2.05 in (52 mm) |
| December | 77.7°F (25°C) | 68.3°F (20°C) | 2.16 in (55 mm) |
The KEY WEST INTL AIRPORT station has no 1991–2020 snowfall normal in ACIS (every month comes back as M), so there is no snowfall column here.
Reading the twelve months
By these station averages, August runs the warmest (90.6°F average high) and January the coolest (75.8°F average high). September averages the most rain (7.24 in) and March the least (1.53 in).
Months within our comfort range
We set one fixed, objective threshold ourselves — average high between 65°F and 80°F, and average rainfall under 2 in — and check each of the twelve rows against it. This is not a claim that any other month is bad, and not our judgment of which month suits any trip; it is just which rows on the table above clear the stated numbers. See how we set this threshold.
January, February, March are the months at Key West that clear both parts of the threshold: January 75.8°F / 1.83 in; February 77.4°F / 1.54 in; March 79.6°F / 1.53 in.
Compared with nearby cities we cover
| City | Annual avg. high | Annual avg. low | Annual rainfall |
|---|---|---|---|
| Key West | 83.7°F | 74°F | 40.4 in |
| Miami, FL | 84.2°F | 70.7°F | 67.4 in |
About the station
These normals are read at a single NOAA/NWS station, KEY WEST INTL AIRPORT (station ID 12836), not averaged across the whole metro area. A different station nearby — higher ground, closer to water, further inland — can read noticeably different numbers, especially for rain. Run this station's ACIS query yourself.
What this page adds
A search for "key west weather by month" mostly returns a day-by-day forecast calendar (useful only for the next two weeks) or a local weather office page built for a different question. This page puts all twelve months of the 1991–2020 average on one screen, in both °F/°C and inches/mm, names the exact station behind the numbers, and sets it next to a few nearby cities so the difference is visible at a glance.
Source: NOAA's current (1991–2020) climate normals, pulled via the Regional Climate Centers' ACIS lookup tool. How we read this data.