Jacksonville weather in September

In September, Jacksonville sees average daytime highs of 86°F and overnight lows near 72°F, with 4.8 in of rain across 15.9 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 88°F in the first days to 84°F by the end. 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 42 min by month's end. Set against the rest of the year, September is Jacksonville's 9th-clearest and 9th-windiest month. For the whole year in context, see Jacksonville's year-round climate.

Daytime high
86°
4th warmest
Overnight low
72°
9th coldest
Rainfall
4.8 in
15.9 wet days
Daylight
12 h 12 min
6:16 AM – 6:26 PM
Cloud cover
63%
9th clearest
Wind
6 mph
9th windiest
Solar energy
4.55 kWh/m²
Travel score
4.2
out of 10

Jacksonville is city in Duval County, and largest city in State of Florida, United States.

Density
446/km²
people per km²
Founded
1791

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 88°F in the first days to 84°F by the end.

A typical September day in Jacksonville reaches about 86°F in the afternoon and slips back to 72°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 81°F and 91°F. Set against its neighbours, September runs about 3°F cooler than August and about 6°F warmer than October.

60°70°80°90°151015202530
Avg high (°F)Avg low (°F)
18874
28873
38873
48873
58773
68773
78773
88773
98773
108773
118772
128772
138772
148772
158672
168672
178671
188671
198671
208671
218571
228571
238570
248570
258570
268570
278469
288469
298469
308469

How September really feels in Jacksonville

Once humidity and wind are folded in, September averages 22 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
22
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.

Jacksonville weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan65° / 45°2.67.310.36.5
Feb69° / 48°2.56.910.96.8
Mar74° / 52°3.07.511.87.4
Apr80° / 59°2.36.912.77.2
May85° / 66°2.68.913.55.4
Jun89° / 72°5.118.913.93.4
Jul90° / 74°4.920.413.82.9
Aug89° / 74°5.521.613.12.9
Sep86° / 72°4.815.912.24.2
Oct80° / 63°2.89.211.36.7
Nov73° / 53°1.6610.57.5
Dec67° / 48°2.36.510.16.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 22% of September, with mostly cloudy or overcast conditions the remaining 54%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14159
24159
34159
44159
54159
64258
74357
84456
94456
104555
114654
124753
134753
144753
154852
164852
174951
184951
194852
204852
214951
224852
234951
244753
254852
264753
274852
284654
294753
304753

Chance of precipitation in September

Any precipitation

Jacksonville gets around 4.8 in of rain over 15.9 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 53% and peaks near 63% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
163
263
362
461
561
660
759
858
958
1057
1156
1255
1355
1454
1553
1653
1752
1851
1951
2050
2149
2249
2348
2448
2547
2647
2747
2846
2946
3045

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 62% of days. Sticky, muggy-or-worse air turns up on roughly 90% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1002127313
2003137212
3013147111
4013157011
5014166910
6014166910
701417699
801518679
901519678
1001520668
1101521667
1201522657
1301623646
1402623636
1502624626
1602724616
1702724625
1802724625
1902824615
2003824614
2113824604
2213924594
23141024583
24241024573
25251124553
26351224533
27351323533
28361324522
29461424502
30461424492

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 36 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 54 minutes over September. Sunrise moves from 6:07 AM to 6:24 AM, and sunset from 6:46 PM to 6:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.66:076:46
212.66:086:44
312.66:086:43
412.66:096:42
512.56:096:41
612.56:106:39
712.56:106:38
812.46:116:37
912.46:126:36
1012.46:126:34
1112.36:136:33
1212.36:136:32
1312.36:146:30
1412.26:146:29
1512.26:156:28
1612.26:166:26
1712.16:166:25
1812.16:176:24
1912.16:176:22
2012.16:186:21
2112.06:186:20
2212.06:196:18
2312.06:206:17
2411.96:206:16
2511.96:216:15
2611.96:216:13
2711.86:226:12
2811.86:226:11
2911.86:236:09
3011.76:246:08

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.55 kWh/m².

For context, solar energy here swings from a low near 2.77 kWh/m² to a high of 6.31 kWh/m² in May across the year — September's 4.55 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
44.8Bright
54.8Bright
64.8Bright
74.8Bright
84.7Bright
94.7Bright
104.7Bright
114.7Bright
124.7Bright
134.6Bright
144.6Bright
154.6Bright
164.5Bright
174.5Bright
184.5Bright
194.5Bright
204.5Bright
214.4Bright
224.4Bright
234.4Bright
244.3Bright
254.3Bright
264.3Bright
274.3Bright
284.2Bright
294.2Bright
304.2Bright
Planning a trip in September

Hazard calendar for Jacksonville

In seasonPeak

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

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

Jacksonville'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 Jacksonville?

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

4.2
Sightseeing
9th-best month of the year
5.8
Beach & pool
5th-best month of the year

September is a reasonable time to visit Jacksonville for sightseeing.

What to pack for Jacksonville in September

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

In September, Jacksonville sees daytime highs around 86°F and nights near 72°F. Pack light clothes and rain gear. Worth having: sun protection. About 16 days see rain.

light clothesrain gearsun protection

Sea temperature near Jacksonville in September

The nearest coast averages about 82°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 17 mi away) is warmest in August at about 82°F and coldest in February near 61°F.

It's comfortable for a long swim from Apr 13 to Nov 28 — about 7.6 months when the water holds above 68°F.

60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan62Cool
Feb61Cool
Mar63Cool
Apr69Refreshing
May75Refreshing
Jun80Warm
Jul82Warm
Aug82Tropical
Sep82Warm
Oct78Warm
Nov70Refreshing
Dec65Cool

UV index in Jacksonville in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Jacksonville peaks around June 22 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 22UV 10Dec 19UV 4
UV index (midday)Level
Jan4Moderate
Feb6High
Mar7High
Apr7High
May8Very high
Jun11Extreme
Jul10Extreme
Aug10Very high
Sep8Very high
Oct6High
Nov5Moderate
Dec3Moderate

Air quality in Jacksonville 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 Jacksonville is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (December, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1618 µg/m³Dec 138 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb13Moderate
Mar12Moderate
Apr13Moderate
May14Moderate
Jun16Moderate
Jul18Moderate
Aug16Moderate
Sep12Good
Oct8Good
Nov8Good
Dec7Good
Location & terrain

Where is Jacksonville?

Jacksonville sits at 30.3°N, 81.7°W, 16 ft above sea level, in United States. The nearest listed city is Fruit Cove, 16 mi away.

Topography around Jacksonville

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

Within 2 miles, the terrain around Jacksonville has only modest variations in elevation — a maximum elevation change of 72 ft around an average of 20 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 154 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 308 ft.

The land around Jacksonville is covered by artificial surfaces (51%) and trees (23%) within 2 miles, trees (49%) and artificial surfaces (23%) within 10 miles, and trees (62%) and water (26%) within 50 miles.

2 miles
72 ft
10 miles
154 ft
50 miles
308 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Fruit Cove 16 mi · Oakleaf Plantation 16 mi · Lakeside 16 mi · Jacksonville Beach 16 mi · Fleming Island 17 mi · Ponte Vedra Beach 17 mi · St. Johns 19 mi · Palm Valley 19 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 Jacksonville (30.3322°, -81.6556°, elevation 16 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).