Stuart weather in September

In September, Stuart sees average daytime highs of 85°F and overnight lows near 78°F, with 5.5 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 85°F through the month. The sky is clear or mostly clear about 24% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 36 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Stuart's 12th-clearest and 9th-windiest month. For the whole year in context, see Stuart's year-round climate.

Daytime high
85°
3rd warmest
Overnight low
78°
10th coldest
Rainfall
5.5 in
19.7 wet days
Daylight
12 h 12 min
6:11 AM – 6:20 PM
Cloud cover
67%
12th clearest
Wind
8 mph
9th windiest
Solar energy
4.95 kWh/m²
Travel score
4.1
out of 10

Stuart is seat of Martin County in Florida, United States.

Density
706/km²
people per km²
Founded
1914

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 85°F through the month.

A typical September day in Stuart reaches about 85°F in the afternoon and slips back to 78°F overnight — a 6°F spread between the day's warmth and the night's chill. On most days the high lands between 82°F and 87°F. Set against its neighbours, September runs about 2°F cooler than August and about 3°F warmer than October.

70°80°90°151015202530
Avg high (°F)Avg low (°F)
18579
28579
38579
48578
58578
68578
78578
88578
98578
108578
118578
128578
138578
148578
158578
168578
178578
188478
198478
208478
218478
228478
238478
248478
258478
268478
278477
288477
298477
308377

How September really feels in Stuart

Once humidity and wind are folded in, September averages 27 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
27
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.

Stuart 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° / 62°2.07.110.57.2
Feb73° / 63°1.86.5117.5
Mar75° / 66°2.37.111.87.6
Apr78° / 70°2.27.112.67.3
May82° / 74°2.91013.36.4
Jun85° / 77°4.817.613.74.4
Jul86° / 79°3.618.213.54.0
Aug86° / 79°4.821133.7
Sep85° / 78°5.519.712.24.1
Oct82° / 75°4.012.211.36.0
Nov77° / 69°2.28.710.77.1
Dec74° / 65°1.67.310.37.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 59%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13466
23466
33466
43466
53466
63565
73664
83763
93862
103961
113961
124258
134258
144258
154357
164357
174357
184456
194456
204456
214456
224456
234456
244456
254456
264357
274357
284456
294456
304555

Chance of precipitation in September

Any precipitation

Stuart gets around 5.5 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 73% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
172
272
373
473
573
672
772
872
971
1070
1169
1268
1367
1466
1565
1664
1763
1862
1962
2061
2160
2260
2359
2459
2559
2659
2758
2858
2957
3057

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 67% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202530
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1026038
2026137
3026335
4036334
5036532
6036631
7036730
8036829
9036928
10046927
11047026
12147025
13156925
14157024
15166924
16167023
17176923
18176923
19177022
20186922
21187021
22296920
23296920
242106919
253116818
263116818
274126717
284126717
295136616
305146516

Wind in September

Winds average 8 mph in September.

Across September, daily wind ranges from about 8 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
199light breeze
209light breeze
219light breeze
229light breeze
239light breeze
249light breeze
259light breeze
269light breeze
279light breeze
289light breeze
299light breeze
309light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 36 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 48 minutes over September. Sunrise moves from 6:04 AM to 6:17 AM, and sunset from 6:38 PM to 6:03 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.66:046:38
212.56:046:37
312.56:056:35
412.56:056:34
512.56:066:33
612.46:066:32
712.46:066:31
812.46:076:30
912.46:076:28
1012.36:086:27
1112.36:086:26
1212.36:096:25
1312.26:096:24
1412.26:106:22
1512.26:106:21
1612.26:116:20
1712.16:116:19
1812.16:116:18
1912.16:126:16
2012.06:126:15
2112.06:136:14
2212.06:136:13
2312.06:146:12
2411.96:146:11
2511.96:156:09
2611.96:156:08
2711.96:166:07
2811.86:166:06
2911.86:176:05
3011.86:176:03

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.95 kWh/m².

For context, solar energy here swings from a low near 3.08 kWh/m² to a high of 6.42 kWh/m² in May across the year — September's 4.95 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.2Bright
65.2Bright
75.2Bright
85.1Bright
95.1Bright
105.1Bright
115.1Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
165.0Bright
174.9Bright
184.9Bright
194.9Bright
204.8Bright
214.8Bright
224.8Bright
234.8Bright
244.7Bright
254.7Bright
264.7Bright
274.6Bright
284.6Bright
294.6Bright
304.6Bright
Planning a trip in September

Hazard calendar for Stuart

In seasonPeak

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

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

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

Is September a good time to visit Stuart?

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

4.1
Sightseeing
10th-best month of the year
5.4
Beach & pool
10th-best month of the year

September is a reasonable time to visit Stuart for sightseeing.

What to pack for Stuart in September

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

In September, Stuart sees daytime highs around 85°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 Stuart in September

The nearest coast averages about 84°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 9 mi away) is warmest in August at about 84°F and coldest in February near 74°F.

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

75°80°85°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan74Refreshing
Feb74Refreshing
Mar75Refreshing
Apr76Warm
May79Warm
Jun82Warm
Jul83Tropical
Aug84Tropical
Sep84Tropical
Oct82Warm
Nov79Warm
Dec77Warm

UV index in Stuart in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Stuart peaks around July 13 at about 11 (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 highHighModerateJul 13UV 11Dec 18UV 5
UV index (midday)Level
Jan5High
Feb7High
Mar9Very high
Apr9Very high
May10Very high
Jun11Extreme
Jul11Extreme
Aug10Extreme
Sep9Very high
Oct8Very high
Nov6High
Dec4Moderate

Air quality in Stuart 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 Stuart is worst in July — around 20 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (December, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1819 µg/m³Dec 138 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb10Good
Mar11Good
Apr11Good
May11Good
Jun15Moderate
Jul20Moderate
Aug17Moderate
Sep12Good
Oct9Good
Nov8Good
Dec8Good
Location & terrain

Where is Stuart?

Stuart sits at 27.2°N, 80.3°W, 10 ft above sea level, in United States. The nearest listed city is Palm City, 2.5 mi away.

Topography around Stuart

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

Within 2 miles, the terrain around Stuart has only modest variations in elevation — a maximum elevation change of 39 ft around an average of 10 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 112 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 200 ft.

The land around Stuart is covered by artificial surfaces (34%), water (34%) and trees (21%) within 2 miles, water (34%), trees (26%) and grassland (20%) within 10 miles, and water (42%) and grassland (22%) within 50 miles.

2 miles
39 ft
10 miles
112 ft
50 miles
200 ft
treesgrasslandcroplandartificial surfaceswaterwetlandmangroves
September weather nearby: Palm City 2.5 mi · Port Saint Lucie 8.7 mi · Fort Pierce 18 mi · Jupiter 21 mi · Palm Beach Gardens 27 mi · Florida Ridge 28 mi · The Acreage 28 mi · Vero Beach South 30 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 Stuart (27.1975°, -80.2528°, elevation 10 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).