Key West weather in December

In December, Key West sees average daytime highs of 75°F and overnight lows near 71°F, with 1.3 in of rain across 5.1 wet days and about 10.5 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 75°F through the month. The sky is clear or mostly clear about 54% of the time in December, and the air most often feels muggy.

Daylight stretches from about 10 h 36 min at the start of December to 10 h 30 min by month's end. Set against the rest of the year, December is Key West's 6th-clearest and 3rd-windiest month. For the whole year in context, see Key West's year-round climate.

Daytime high
75°
9th warmest
Overnight low
71°
4th coldest
Rainfall
1.3 in
5.1 wet days
Daylight
10 h 30 min
7:09 AM – 5:38 PM
Cloud cover
42%
6th clearest
Wind
15 mph
3rd windiest
Solar energy
3.66 kWh/m²
Travel score
8.0
out of 10

Key West is county seat of Monroe County, Florida, United States.

Density
1,373/km²
people per km²
Founded
1828

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 75°F through the month.

A typical December day in Key West reaches about 75°F in the afternoon and slips back to 71°F overnight — a 3°F spread between the day's warmth and the night's chill. On most days the high lands between 70°F and 78°F. Set against its neighbours, December runs about 3°F cooler than November and about 2°F warmer than January.

60°70°80°151015202531
Avg high (°F)Avg low (°F)
17673
27673
37673
47673
57673
67572
77572
87572
97572
107572
117572
127572
137572
147572
157572
167571
177571
187471
197471
207471
217471
227471
237471
247471
257471
267471
277471
287471
297471
307470
317470

How December really feels in Key West

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Key West weather by month

How December compares with the rest of the year at a glance. December is the 9th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan73° / 69°1.55.710.67.8
Feb73° / 70°1.2411.18.1
Mar74° / 71°1.04.211.88.4
Apr77° / 74°1.54.512.68.3
May80° / 77°2.67.913.27.3
Jun83° / 80°4.112.713.55.7
Jul84° / 81°2.512.913.45.3
Aug84° / 81°4.116.112.94.8
Sep83° / 80°5.417.712.24.7
Oct81° / 78°4.612.711.46.2
Nov77° / 74°1.55.810.87.8
Dec75° / 71°1.35.110.58.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 54% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 29%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17525
27525
37525
47426
57426
67426
77327
87327
97327
107228
117129
127129
137030
147030
156931
166931
176931
186931
196832
206832
216931
226832
236832
246832
256931
266832
276832
286931
296931
306931
317030

Chance of precipitation in December

Any precipitation

Key West gets around 1.3 in of rain over 5.1 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 17% and peaks near 18% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
118
218
318
418
518
618
718
818
918
1018
1118
1218
1318
1417
1517
1617
1717
1817
1917
2016
2116
2216
2316
2416
2516
2616
2716
2816
2916
3016
3116

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the muggy band about 35% of days. Sticky, muggy-or-worse air turns up on roughly 58% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1510184324
2510184224
3610184224
4610184125
5710184025
6710184026
7810173926
8811173826
9811173726
10911173626
11912173626
12912183526
131013183426
141013183325
151013193325
161014193225
171014203124
181114213124
191115213123
201015223122
211015223122
221015233121
231015233121
241014233121
251014233121
261014233221
271113233221
281113223222
291113223222
301213213222
311214213221

Wind in December

Winds average 15 mph in December.

Across December, daily wind ranges from about 14 mph on the calmest days to 15 mph at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (mph)Feels
115breezy
215breezy
315breezy
415breezy
514breezy
614breezy
714breezy
814breezy
914breezy
1014breezy
1114breezy
1214breezy
1315breezy
1415breezy
1515breezy
1615breezy
1715breezy
1815breezy
1915breezy
2015breezy
2115breezy
2215breezy
2315breezy
2415breezy
2515breezy
2615breezy
2715breezy
2815breezy
2915breezy
3015breezy
3115breezy

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 36 min at the start of December to 10 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:59 AM to 7:15 AM, and sunset from 5:34 PM to 5:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.66:595:34
210.67:005:35
310.67:015:35
410.67:015:35
510.57:025:35
610.57:035:35
710.57:035:35
810.57:045:35
910.57:055:36
1010.57:055:36
1110.57:065:36
1210.57:065:37
1310.57:075:37
1410.57:085:37
1510.57:085:38
1610.57:095:38
1710.57:095:38
1810.57:105:39
1910.57:105:39
2010.57:115:39
2110.57:115:40
2210.57:125:40
2310.57:125:41
2410.57:135:41
2510.57:135:42
2610.57:145:42
2710.57:145:43
2810.57:145:43
2910.57:155:44
3010.57:155:45
3110.57:155:45

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3.66 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3.66 kWh/m² to a high of 6.9 kWh/m² in May across the year — December's 3.66 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.8Moderate
43.8Moderate
53.8Moderate
63.7Moderate
73.7Moderate
83.7Moderate
93.7Moderate
103.7Moderate
113.7Moderate
123.7Moderate
133.6Moderate
143.6Moderate
153.6Moderate
163.6Moderate
173.6Moderate
183.6Moderate
193.6Moderate
203.6Moderate
213.6Moderate
223.6Moderate
233.6Moderate
243.6Moderate
253.6Moderate
263.6Moderate
273.6Moderate
283.7Moderate
293.7Moderate
303.7Moderate
313.7Moderate
Planning a trip in December

Hazard calendar for Key West

In seasonPeak

None of Key West's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Key West sits in the Atlantic hurricane belt; the season peaks August–October.

Key West's rainy season runs May–October, when most of the year's rain falls.

Atlantic hurricane
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Key West?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

8.0
Sightseeing
4th-best month of the year
6.6
Beach & pool
5th-best month of the year

December is one of the better times to visit Key West for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Key West in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Key West sees daytime highs around 75°F and nights near 71°F. Worth packing: light clothes and a windbreaker. About 5 days see rain.

light clothesa windbreaker

Sea temperature near Key West in December

The nearest coast averages about 75°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 86°F and coldest in February near 73°F.

The water stays above 68°F all year — warm enough for a swim any month.

70°75°80°85°90°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan73Refreshing
Feb73Refreshing
Mar74Refreshing
Apr77Warm
May80Warm
Jun83Tropical
Jul85Tropical
Aug86Tropical
Sep85Tropical
Oct83Tropical
Nov78Warm
Dec75Warm

UV index in Key West in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Key West peaks around July 18 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 at about 5 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJul 18UV 12Dec 18UV 5
UV index (midday)Level
Jan6High
Feb8Very high
Mar10Very high
Apr11Extreme
May11Extreme
Jun11Extreme
Jul12Extreme
Aug12Extreme
Sep11Extreme
Oct9Very high
Nov6High
Dec5High

Air quality in Key West in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Key West is worst in July — around 18 µg/m³ PM2.5 (moderate), about 4.1× the cleanest month (December, 4 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1818 µg/m³Dec 144 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb5Good
Mar6Good
Apr8Good
May9Good
Jun15Moderate
Jul18Moderate
Aug16Moderate
Sep10Good
Oct7Good
Nov5Good
Dec4Good
Location & terrain

Where is Key West?

Key West sits at 24.6°N, 81.8°W, 3 ft above sea level, in United States. The nearest listed city is Marco Island, 96 mi away.

Topography around Key West

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Key West.

Within 2 miles, the terrain around Key West has only modest variations in elevation — a maximum elevation change of 39 ft around an average of 3 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 75 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 52 ft.

The land around Key West is covered by water (64%) and artificial surfaces (26%) within 2 miles, water (95%) within 10 miles, and water (98%) within 50 miles.

2 miles
39 ft
10 miles
75 ft
50 miles
52 ft
treesgrasslandartificial surfacesbare terrainwatermangroves
December weather nearby: Marco Island 96 mi · Santa Cruz del Norte 98 mi · Alamar 101 mi · Cojímar 101 mi · Ciudad Camilo Cienfuegos 103 mi · Varadero 103 mi · Homestead 103 mi · Guanabacoa 104 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Key West (24.5552°, -81.7816°, elevation 3 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).