Pontiac weather in September

In September, Pontiac sees average daytime highs of 72°F and overnight lows near 54°F, with 3.0 in of rain across 9.5 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 76°F in the first days to 67°F by the end. The sky is clear or mostly clear about 34% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Pontiac's 1st-clearest and 9th-windiest month. For the whole year in context, see Pontiac's year-round climate.

Daytime high
72°
4th warmest
Overnight low
54°
9th coldest
Rainfall
3.0 in
9.5 wet days
Daylight
12 h 18 min
6:19 AM – 6:36 PM
Cloud cover
56%
1st clearest
Wind
7 mph
9th windiest
Solar energy
4.25 kWh/m²
Travel score
6.8
out of 10

Pontiac is city and county seat of Oakland County, Michigan, United States.

Density
1,140/km²
people per km²
Founded
1818

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 76°F in the first days to 67°F by the end.

A typical September day in Pontiac reaches about 72°F in the afternoon and slips back to 54°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 61°F and 82°F. Set against its neighbours, September runs about 7°F cooler than August and about 13°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17759
27759
37658
47658
57658
67558
77557
87557
97456
107456
117456
127355
137355
147355
157254
167254
177253
187153
197153
207052
217052
227051
236951
246951
256850
266850
276750
286749
296749
306649

How September really feels in Pontiac

Once humidity and wind are folded in, September 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

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Pontiac weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan31° / 18°2.39.679.20.0
Feb33° / 19°2.07.96.710.30.0
Mar44° / 27°2.49.94.211.60.8
Apr56° / 38°3.612.11.913.13.6
May67° / 49°3.912.70.114.45.8
Jun77° / 59°3.911.2015.16.5
Jul81° / 63°3.311.5014.86.3
Aug79° / 61°3.210.6013.76.6
Sep72° / 54°3.09.5012.36.8
Oct59° / 43°3.0100.210.84.6
Nov46° / 33°2.69.32.29.61.2
Dec35° / 24°2.29.35.68.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 48%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15545
25545
35644
45644
55644
65545
75545
85545
95545
105545
115446
125446
135347
145347
155248
165149
175149
185149
195050
205050
215050
224951
234951
244852
254852
264852
274654
284654
294654
304753

Chance of precipitation in September

Any precipitation

Pontiac gets around 3.0 in of rain over 9.5 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 32% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
131
231
331
431
531
631
731
831
931
1031
1131
1231
1331
1431
1531
1631
1730
1830
1930
2031
2131
2231
2332
2433
2533
2634
2734
2834
2934
3034

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 56% of days. Sticky, muggy-or-worse air turns up on roughly 9% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1312821192
2332820182
3352819172
4362818161
5382818151
6402817141
7422717131
8442716121
9452716111
10472615111
11482615101
1250251591
1352251490
1454241480
1556231470
1657231370
1758221370
1861211260
1961211260
2064201150
2166191050
2267181050
236918940
247117840
257316830
267416730
277515730
287614730
297814620
307913620

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.

0246810151015202530
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 6:02 AM to 6:35 AM, and sunset from 7:03 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.06:027:03
213.06:037:02
312.96:057:00
412.96:066:58
512.86:076:56
612.86:086:54
712.76:096:53
812.76:106:51
912.66:116:49
1012.66:126:47
1112.56:136:45
1212.56:156:43
1312.46:166:42
1412.46:176:40
1512.36:186:38
1612.36:196:36
1712.26:206:34
1812.26:216:32
1912.16:226:30
2012.16:236:29
2112.06:256:27
2212.06:266:25
2311.96:276:23
2411.96:286:21
2511.86:296:19
2611.86:306:18
2711.76:316:16
2811.76:326:14
2911.66:346:12
3011.66:356:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.25 kWh/m².

For context, solar energy here swings from a low near 1.39 kWh/m² to a high of 6.29 kWh/m² in June across the year — September's 4.25 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.7Bright
44.7Bright
54.7Bright
64.6Bright
74.6Bright
84.5Bright
94.5Bright
104.5Bright
114.4Bright
124.4Bright
134.3Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.1Bright
194.1Bright
204.0Bright
214.0Bright
224.0Moderate
233.9Moderate
243.9Moderate
253.8Moderate
263.8Moderate
273.7Moderate
283.7Moderate
293.7Moderate
303.6Moderate
Planning a trip in September

Is September a good time to visit Pontiac?

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

6.8
Sightseeing
1st-best month of the year
4.7
Beach & pool
4th-best month of the year

September is a reasonable time to visit Pontiac for sightseeing.

What to pack for Pontiac in September

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

In September, Pontiac sees daytime highs around 72°F and nights near 54°F. Worth packing: light clothes and rain gear. About 10 days see rain.

light clothesrain gear

Sea temperature near Pontiac in September

The nearest coast averages about 68°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 21 mi away) is warmest in August at about 73°F and coldest in February near 33°F.

It's comfortable for a long swim from Jul 2 to Sep 15 — about 2.5 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan34Bracing
Feb33Bracing
Mar34Bracing
Apr41Bracing
May52Bracing
Jun64Cool
Jul72Refreshing
Aug73Refreshing
Sep68Refreshing
Oct57Bracing
Nov47Bracing
Dec39Bracing

UV index in Pontiac in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Pontiac peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 20UV 9Dec 20UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr5High
May7High
Jun9Very high
Jul8Very high
Aug7High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Pontiac 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 Pontiac is worst in July — around 15 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1415 µg/m³Oct 238 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar14Moderate
Apr13Moderate
May15Moderate
Jun15Moderate
Jul15Moderate
Aug15Moderate
Sep12Moderate
Oct8Good
Nov9Good
Dec9Good
Location & terrain

Where is Pontiac?

Pontiac sits at 42.6°N, 83.3°W, 922 ft above sea level, in United States. The nearest listed city is Auburn Hills, 4.3 mi away.

Topography around Pontiac

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

Within 2 miles, the terrain around Pontiac has only modest variations in elevation — a maximum elevation change of 194 ft around an average of 951 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 614 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 915 ft.

The land around Pontiac is covered by artificial surfaces (40%), trees (35%) and grassland (20%) within 2 miles, trees (59%) within 10 miles, and trees (38%) and cropland (29%) within 50 miles.

2 miles
194 ft
10 miles
614 ft
50 miles
915 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Auburn Hills 4.3 mi · West Bloomfield Township 6.8 mi · Waterford 7.5 mi · Rochester Hills 7.5 mi · Troy 7.5 mi · Birmingham 7.5 mi · Berkley 11 mi · Farmington Hills 11 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 Pontiac (42.6389°, -83.291°, elevation 922 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. 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).