Marco Island weather in September

In September, Marco Island sees average daytime highs of 86°F and overnight lows near 78°F, with 5.9 in of rain across 19.7 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 86°F through the month. The sky is clear or mostly clear about 25% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 30 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Marco Island's 10th-clearest and 9th-windiest month. For the whole year in context, see Marco Island's year-round climate.

Daytime high
86°
3rd warmest
Overnight low
78°
10th coldest
Rainfall
5.9 in
19.7 wet days
Daylight
12 h 12 min
6:17 AM – 6:26 PM
Cloud cover
66%
10th clearest
Wind
7 mph
9th windiest
Solar energy
5.2 kWh/m²
Travel score
3.9
out of 10

Marco Island is city in Collier County, Florida, United States.

Founded
1886

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 86°F through the month.

A typical September day in Marco Island reaches about 86°F in the afternoon and slips back to 78°F overnight — a 8°F spread between the day's warmth and the night's chill. On most days the high lands between 83°F and 88°F. Set against its neighbours, September runs on par with August and about 3°F warmer than October.

70°80°90°151015202530
Avg high (°F)Avg low (°F)
18679
28679
38678
48678
58678
68678
78678
88678
98678
108678
118678
128678
138678
148678
158678
168678
178678
188678
198678
208578
218578
228577
238577
248577
258577
268577
278577
288577
298577
308577

How September really feels in Marco Island

Once humidity and wind are folded in, September averages 30 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
30
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Marco Island weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan72° / 61°1.5510.67.7
Feb73° / 62°1.13.911.18.1
Mar76° / 65°1.34.211.88.2
Apr80° / 69°1.65.512.67.6
May84° / 74°2.79.113.36.0
Jun86° / 78°5.919.413.64.0
Jul87° / 79°5.020.813.53.6
Aug87° / 79°5.521.612.93.5
Sep86° / 78°5.919.712.23.9
Oct83° / 74°3.19.111.46.1
Nov78° / 68°1.33.810.78.0
Dec74° / 64°1.1410.48.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 58%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13367
23367
33367
43466
53466
63565
73763
83862
93961
104060
114159
124258
134357
144357
154456
164555
174654
184555
194555
204555
214555
224456
234555
244555
254456
264456
274555
284555
294753
304753

Chance of precipitation in September

Any precipitation

Marco Island gets around 5.9 in of rain over 19.7 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 65% and peaks near 72% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
172
272
372
472
571
671
771
870
970
1069
1168
1268
1367
1466
1566
1665
1764
1864
1963
2063
2162
2261
2360
2460
2559
2657
2756
2855
2954
3052

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 59% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1015049
2015148
3015247
4015346
5015445
6015544
7015643
8015841
9015940
10025939
11026038
12026038
13026137
14036136
15036136
16036235
17046135
18046135
19056134
20056134
21056134
22066133
23166132
24176032
25186031
26186130
27196030
282105929
292115928
302116027

Wind in September

Winds average 7 mph in September.

Across September, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107light breeze
117light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 30 min at the start of September to 11 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 42 minutes over September. Sunrise moves from 6:11 AM to 6:23 AM, and sunset from 6:43 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.56:116:43
212.56:116:42
312.56:116:40
412.56:126:39
512.46:126:38
612.46:136:37
712.46:136:36
812.46:136:35
912.36:146:34
1012.36:146:33
1112.36:156:31
1212.36:156:30
1312.26:156:29
1412.26:166:28
1512.26:166:27
1612.26:176:26
1712.16:176:25
1812.16:186:23
1912.16:186:22
2012.06:186:21
2112.06:196:20
2212.06:196:19
2312.06:206:18
2411.96:206:16
2511.96:206:15
2611.96:216:14
2711.96:216:13
2811.86:226:12
2911.86:226:11
3011.86:236:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.2 kWh/m².

For context, solar energy here swings from a low near 3.55 kWh/m² to a high of 6.75 kWh/m² in May across the year — September's 5.2 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.4Bright
65.4Bright
75.4Bright
85.4Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.2Bright
155.2Bright
165.2Bright
175.2Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.0Bright
235.0Bright
245.0Bright
255.0Bright
264.9Bright
274.9Bright
284.9Bright
294.9Bright
304.9Bright
Planning a trip in September

Hazard calendar for Marco Island

In seasonPeak

In September, Marco Island sits inside its atlantic hurricane and rainy season season. The full year is below, with each hazard's peak months called out.

Marco Island sits in the Atlantic hurricane belt; the season peaks August–October.

Marco Island'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 September a good time to visit Marco Island?

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

3.9
Sightseeing
10th-best month of the year
5.3
Beach & pool
10th-best month of the year

September is a weaker month for outdoor sightseeing in Marco Island.

What to pack for Marco Island in September

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

In September, Marco Island sees daytime highs around 86°F and nights near 78°F. Pack light clothes and rain gear. Worth having: sun protection. About 20 days see rain.

light clothesrain gearsun protection

Sea temperature near Marco Island in September

The nearest coast averages about 85°F in September — 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 January near 69°F.

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

70°80°90°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan69Refreshing
Feb69Refreshing
Mar72Refreshing
Apr76Warm
May81Warm
Jun84Tropical
Jul86Tropical
Aug86Tropical
Sep85Tropical
Oct82Warm
Nov76Warm
Dec72Refreshing

UV index in Marco Island in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Marco Island peaks around July 17 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 at about 5 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJul 17UV 12Dec 18UV 5
UV index (midday)Level
Jan5High
Feb7Very high
Mar9Very high
Apr10Very high
May10Extreme
Jun11Extreme
Jul12Extreme
Aug11Extreme
Sep10Very high
Oct8Very high
Nov6High
Dec5Moderate

Air quality in Marco Island in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Marco Island is worst in July — around 20 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (December, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1819 µg/m³Dec 147 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar12Good
Apr10Good
May11Good
Jun15Moderate
Jul20Moderate
Aug17Moderate
Sep12Moderate
Oct9Good
Nov8Good
Dec7Good
Location & terrain

Where is Marco Island?

Marco Island sits at 25.9°N, 81.7°W, 3 ft above sea level, in United States. The nearest listed city is East Naples, 14 mi away.

Topography around Marco Island

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

Within 2 miles, the terrain around Marco Island has only modest variations in elevation — a maximum elevation change of 43 ft around an average of 7 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 62 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 98 ft.

The land around Marco Island is covered by water (44%) and artificial surfaces (42%) within 2 miles, water (64%) and mangroves (20%) within 10 miles, and water (44%) and trees (21%) within 50 miles.

2 miles
43 ft
10 miles
62 ft
50 miles
98 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
September weather nearby: East Naples 14 mi · Naples 15 mi · Golden Gate 17 mi · Bonita Springs 28 mi · Estero 35 mi · San Carlos Park 37 mi · Immokalee 38 mi · Iona 43 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 Marco Island (25.9412°, -81.7184°, 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).