Key West weather in May

In May, Key West sees average daytime highs of 80°F and overnight lows near 77°F, with 2.6 in of rain across 7.9 wet days and about 13.2 hours of daylight. It is the 6th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 80°F through the month. The sky is clear or mostly clear about 62% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 h 54 min at the start of May to 13 h 24 min by month's end. Set against the rest of the year, May is Key West's 4th-clearest and 8th-windiest month. For the whole year in context, see Key West's year-round climate.

Daytime high
80°
6th warmest
Overnight low
77°
7th coldest
Rainfall
2.6 in
7.9 wet days
Daylight
13 h 12 min
5:48 AM – 6:59 PM
Cloud cover
36%
4th clearest
Wind
12 mph
8th windiest
Solar energy
6.9 kWh/m²
Travel score
7.3
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 May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 80°F through the month.

A typical May day in Key West reaches about 80°F in the afternoon and slips back to 77°F overnight — a 2°F spread between the day's warmth and the night's chill. On most days the high lands between 77°F and 82°F. Set against its neighbours, May runs about 3°F warmer than April and about 3°F cooler than June.

65°70°75°80°85°151015202531
Avg high (°F)Avg low (°F)
17876
27876
37876
47876
57976
67976
77976
87977
97977
107977
117977
127977
137977
148077
158077
168077
178077
188078
198078
208078
218078
228078
238078
248078
258178
268178
278178
288178
298178
308179
318179

How May really feels in Key West

Once humidity and wind are folded in, May 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

May 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 May compares with the rest of the year at a glance. May is the 6th-warmest and 5th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 62% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 10% of May, with mostly cloudy or overcast conditions the remaining 27%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
18020
28020
38020
48020
58119
68119
78119
88020
98020
107921
117921
127723
137723
147624
157426
167327
177228
187129
197030
206931
216832
226832
236832
246733
256634
266535
276436
286337
296238
306139
315941

Chance of precipitation in May

Any precipitation

Key West gets around 2.6 in of rain over 7.9 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 26% and peaks near 40% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
118
218
318
417
517
617
717
817
917
1018
1118
1219
1320
1422
1523
1624
1726
1827
1929
2030
2131
2233
2334
2435
2536
2636
2737
2838
2939
3040
3140

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the oppressive band about 59% of days. Sticky, muggy-or-worse air turns up on roughly 91% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1141333444
2141333454
3141332464
4141332474
5131332484
6131331493
7131231503
8031231513
9031131523
10021130543
11021030553
1202929573
1302929573
1402828593
1502727613
1601727614
1701626634
1801525645
1901425655
2001424656
2101323667
2201322668
2301221679
24012196810
25012186811
26011176912
27011156914
28001147015
29001127017
30000117019
31000106921

Wind in May

Winds average 12 mph in May.

Across May, daily wind ranges from about 11 mph on the calmest days to 13 mph at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (mph)Feels
113breezy
213breezy
313breezy
413breezy
513breezy
613breezy
713breezy
813breezy
913breezy
1012breezy
1112light breeze
1212light breeze
1312light breeze
1412light breeze
1512light breeze
1612light breeze
1712light breeze
1812light breeze
1912light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2511light breeze
2611light breeze
2711light breeze
2811light breeze
2911light breeze
3011light breeze
3111light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 54 min at the start of May to 13 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 30 minutes over May. Sunrise moves from 5:57 AM to 5:43 AM, and sunset from 6:51 PM to 7:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:576:51
212.95:566:52
312.95:566:52
413.05:556:53
513.05:546:53
613.05:546:54
713.05:536:54
813.05:526:55
913.15:526:55
1013.15:516:56
1113.15:506:56
1213.15:506:57
1313.15:496:57
1413.25:496:58
1513.25:486:58
1613.25:486:59
1713.25:477:00
1813.25:477:00
1913.25:467:01
2013.35:467:01
2113.35:467:02
2213.35:457:02
2313.35:457:03
2413.35:447:03
2513.35:447:04
2613.35:447:04
2713.35:447:05
2813.45:437:05
2913.45:437:05
3013.45:437:06
3113.45:437:06

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.9 kWh/m² — the sunniest month for solar.

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 — May's 6.9 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.0Intense
27.0Intense
37.0Intense
47.0Intense
57.0Intense
67.0Intense
77.0Intense
87.0Intense
97.0Intense
107.0Intense
117.0Intense
127.0Intense
137.0Intense
146.9Intense
156.9Intense
166.9Intense
176.9Intense
186.8Intense
196.8Intense
206.8Intense
216.8Intense
226.7Intense
236.7Intense
246.7Intense
256.7Intense
266.6Intense
276.6Intense
286.6Intense
296.5Intense
306.5Intense
316.5Intense
Planning a trip in May

Hazard calendar for Key West

In seasonPeak

In May, Key West sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

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 May a good time to visit Key West?

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

7.3
Sightseeing
7th-best month of the year
7.1
Beach & pool
2nd-best month of the year

May 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 May

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

In May, Key West sees daytime highs around 80°F and nights near 77°F. Pack sun protection. Worth having: light clothes. About 8 days see rain.

sun protectionlight clothes

Sea temperature near Key West in May

The nearest coast averages about 80°F in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 11 (very high — sun protection essential). 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 May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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
May 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).