Iona weather in September

In September, Iona sees average daytime highs of 85°F and overnight lows near 78°F, with 5.6 in of rain across 18.2 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 2nd-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 29% 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 Iona's 10th-clearest and 9th-windiest month. For the whole year in context, see Iona's year-round climate.

Daytime high
85°
3rd warmest
Overnight low
78°
10th coldest
Rainfall
5.6 in
18.2 wet days
Daylight
12 h 12 min
6:18 AM – 6:27 PM
Cloud cover
64%
10th clearest
Wind
8 mph
9th windiest
Solar energy
5.09 kWh/m²
Travel score
4.1
out of 10

Iona is census-designated place in Lee County, Florida, United States.

Density
580/km²
people per km²

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 Iona reaches about 85°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 82°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)
18678
28678
38678
48678
58678
68678
78678
88678
98678
108678
118678
128678
138678
148678
158578
168578
178578
188578
198577
208577
218577
228577
238577
248577
258577
268577
278577
288576
298576
308476

How September really feels in Iona

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.

Iona weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan70° / 59°1.84.910.57.5
Feb72° / 61°1.44.411.17.8
Mar75° / 64°1.64.811.88.1
Apr79° / 69°1.75.812.67.7
May83° / 74°2.48.313.36.4
Jun85° / 78°5.618.213.64.2
Jul86° / 79°4.92013.53.8
Aug86° / 79°5.220.812.93.6
Sep85° / 78°5.618.212.24.1
Oct82° / 73°2.88.511.46.4
Nov77° / 67°1.33.710.78.1
Dec73° / 62°1.44.310.47.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% 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 55%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13664
23763
33763
43763
53961
63961
74060
84159
94159
104357
114456
124555
134555
144753
154753
164753
174852
184753
194852
204951
214852
224852
234852
244951
254852
264852
274951
284951
295050
305050

Chance of precipitation in September

Any precipitation

Iona gets around 5.6 in of rain over 18.2 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 60% and peaks near 68% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
168
268
368
468
568
668
767
867
966
1066
1165
1264
1363
1462
1561
1660
1759
1859
1958
2057
2156
2256
2355
2454
2553
2652
2751
2850
2949
3047

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 99% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10015643
20015742
30015841
40015940
50025939
60026038
70026137
80026236
90026335
100036334
110036433
120036532
130046432
140046531
150056431
160056530
170066430
180066430
190076429
200176329
210186229
220186328
230196327
240296326
2502106325
2602106424
2703116224
2813116223
2913126222
3014136121

Wind in September

Winds average 8 mph in September.

Across September, daily wind ranges from about 7 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
17calm
27light 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
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
289light breeze
299light breeze
309light 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 6:24 AM, and sunset from 6:44 PM to 6:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.56:116:44
212.56:126:43
312.56:126:42
412.56:126:41
512.46:136:40
612.46:136:38
712.46:146:37
812.46:146:36
912.36:156:35
1012.36:156:34
1112.36:156:33
1212.36:166:31
1312.26:166:30
1412.26:176:29
1512.26:176:28
1612.26:186:27
1712.16:186:26
1812.16:186:24
1912.16:196:23
2012.06:196:22
2112.06:206:21
2212.06:206:20
2312.06:216:19
2411.96:216:17
2511.96:216:16
2611.96:226:15
2711.96:226:14
2811.86:236:13
2911.86:236:12
3011.86:246:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.09 kWh/m².

For context, solar energy here swings from a low near 3.44 kWh/m² to a high of 6.71 kWh/m² in May across the year — September's 5.09 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.2Bright
105.2Bright
115.2Bright
125.2Bright
135.1Bright
145.1Bright
155.1Bright
165.1Bright
175.0Bright
185.0Bright
195.0Bright
205.0Bright
215.0Bright
224.9Bright
234.9Bright
244.9Bright
254.9Bright
264.8Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
Planning a trip in September

Hazard calendar for Iona

In seasonPeak

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

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

Iona's rainy season runs June–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 Iona?

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
5.6
Beach & pool
8th-best month of the year

September is a reasonable time to visit Iona for sightseeing.

What to pack for Iona in September

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

In September, Iona sees daytime highs around 85°F and nights near 78°F. Pack light clothes and rain gear. Worth having: sun protection. About 18 days see rain.

light clothesrain gearsun protection

Sea temperature near Iona 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 at the nearest coast (about 11 mi away) is warmest in August at about 86°F and coldest in January near 68°F.

It's comfortable for a long swim from Feb 11 to Jan 16 — about 11.2 months when the water holds above 68°F.

70°80°90°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan68Cool
Feb68Refreshing
Mar71Refreshing
Apr76Warm
May80Warm
Jun84Tropical
Jul86Tropical
Aug86Tropical
Sep85Tropical
Oct81Warm
Nov75Warm
Dec71Refreshing

UV index in Iona 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 Iona peaks around July 17 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 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 17UV 11Dec 17UV 5
UV index (midday)Level
Jan5High
Feb7Very high
Mar9Very high
Apr10Very high
May10Very high
Jun10Extreme
Jul12Extreme
Aug10Extreme
Sep10Very high
Oct8Very high
Nov6High
Dec5Moderate

Air quality in Iona 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 Iona 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 Iona?

Iona sits at 26.5°N, 82.0°W, 7 ft above sea level, in United States. The nearest listed city is Cape Coral, 3.1 mi away.

Topography around Iona

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

Within 2 miles, the terrain around Iona has only modest variations in elevation — a maximum elevation change of 39 ft around an average of 7 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 89 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 164 ft.

The land around Iona is covered by water (42%) and artificial surfaces (28%) within 2 miles, water (41%) and artificial surfaces (23%) within 10 miles, and water (37%), trees (30%) and grassland (20%) within 50 miles.

2 miles
39 ft
10 miles
89 ft
50 miles
164 ft
treesgrasslandcroplandartificial surfaceswaterwetlandmangroves
September weather nearby: Cape Coral 3.1 mi · Fort Myers 11 mi · San Carlos Park 11 mi · Estero 11 mi · North Fort Myers 11 mi · Bonita Springs 17 mi · Lehigh Acres 22 mi · Naples 28 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 Iona (26.5204°, -81.964°, elevation 7 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).