Chatham weather in September

In September, Chatham sees average daytime highs of 22°C and overnight lows near 13°C, with 73 mm of rain across 8.7 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 24°C in the first days to 19°C by the end. The sky is clear or mostly clear about 38% 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 Chatham's 2nd-clearest and 9th-windiest month. For the whole year in context, see Chatham's year-round climate.

Daytime high
22°
4th warmest
Overnight low
13°
9th coldest
Rainfall
73 mm
8.7 wet days
Daylight
12 h 18 min
6:15 AM – 6:32 PM
Cloud cover
53%
2nd clearest
Wind
13 km/h
9th windiest
Solar energy
4.38 kWh/m²
Travel score
6.9
out of 10

Chatham is community in Ontario, Canada.

Air quality
Good
PM2.5 7 µg/m³ · 2019
Founded
1998

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 24°C in the first days to 19°C by the end.

A typical September day in Chatham reaches about 22°C in the afternoon and slips back to 13°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 27°C. Set against its neighbours, September runs about 4°C cooler than August and about 7°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12516
22516
32516
42416
52415
62415
72415
82415
92415
102314
112314
122314
132314
142314
152214
162213
172213
182213
192213
202112
212112
222112
232112
242012
252011
262011
272011
281911
291911
301910

How September really feels in Chatham

Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
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.

Chatham 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 (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-1° / -7°6610.56.69.30.0
Feb / -7°548.5610.30.0
Mar / -3°6610.24.411.60.5
Apr13° / 8912.21.313.13.3
May19° / 10°9212.3014.45.7
Jun25° / 15°9411.20156.6
Jul27° / 18°8611.1014.86.5
Aug26° / 17°7710.4013.76.8
Sep22° / 13°738.7012.36.9
Oct15° / 7610.3010.84.6
Nov / 719.71.99.61.4
Dec / -3°6310.1590.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 38% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16040
26040
35941
46040
55941
65941
75941
85842
95842
105743
115743
125644
135644
145446
155446
165446
175446
185446
195446
205347
215347
225347
235347
245347
255248
265248
275248
285248
295149
305149

Chance of precipitation in September

Any precipitation

Chatham gets around 73 mm of rain over 8.7 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 30% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
128
228
328
428
528
628
728
828
928
1028
1128
1228
1328
1428
1528
1628
1729
1829
1929
2029
2130
2230
2331
2432
2532
2633
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 48% of days. Sticky, muggy-or-worse air turns up on roughly 12% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1242623215
2262623205
3272623195
4292623184
5312623174
6322623164
7342522153
8362522153
9372422143
10392422132
11402421132
12422321122
13442321121
14452320111
15472220101
16492219101
1751221890
1853211790
1955211680
2056211580
2158211470
2258211470
2361201360
2462201260
2564201150
2666191050
2766191050
286719950
297018840
307018840

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
112light breeze
212light breeze
312light breeze
412light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3015light 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 5:58 AM to 6:30 AM, and sunset from 6:59 PM to 6:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:586:59
213.05:596:57
312.96:006:55
412.96:016:53
512.86:036:52
612.86:046:50
712.76:056:48
812.76:066:46
912.66:076:44
1012.66:086:43
1112.56:096:41
1212.56:106:39
1312.46:116:37
1412.46:126:35
1512.36:136:33
1612.36:156:32
1712.26:166:30
1812.26:176:28
1912.16:186:26
2012.16:196:24
2112.06:206:22
2212.06:216:20
2311.96:226:19
2411.96:236:17
2511.86:256:15
2611.86:266:13
2711.76:276:11
2811.76:286:10
2911.66:296:08
3011.66:306:06

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.38 kWh/m².

For context, solar energy here swings from a low near 1.45 kWh/m² to a high of 6.53 kWh/m² in June across the year — September's 4.38 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
15.0Bright
24.9Bright
34.9Bright
44.8Bright
54.8Bright
64.8Bright
74.7Bright
84.7Bright
94.6Bright
104.6Bright
114.5Bright
124.5Bright
134.5Bright
144.4Bright
154.4Bright
164.3Bright
174.3Bright
184.3Bright
194.2Bright
204.2Bright
214.1Bright
224.1Bright
234.0Bright
244.0Bright
254.0Moderate
263.9Moderate
273.9Moderate
283.8Moderate
293.8Moderate
303.7Moderate
Planning a trip in September

Is September a good time to visit Chatham?

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

6.9
Sightseeing
1st-best month of the year
4.8
Beach & pool
4th-best month of the year

September is a reasonable time to visit Chatham for sightseeing.

What to pack for Chatham in September

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

In September, Chatham sees daytime highs around 22°C and nights near 13°C. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

Sea temperature near Chatham in September

The nearest coast averages about 21°C 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 32 km away) is warmest in August at about 24°C and coldest in February near 1°C.

It's comfortable for a long swim from Jun 29 to Sep 23 — about 2.9 months when the water holds above 20°C.

0°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan2Bracing
Feb1Bracing
Mar1Bracing
Apr5Bracing
May11Bracing
Jun18Cool
Jul23Refreshing
Aug24Refreshing
Sep21Refreshing
Oct16Cool
Nov10Bracing
Dec5Bracing

UV index in Chatham 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 Chatham peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 21UV 9Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr6High
May7High
Jun9Very high
Jul9Very high
Aug7High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low
Location & terrain

Where is Chatham?

Chatham sits at 42.4°N, 82.2°W, 183 m above sea level, in Canada. The nearest listed city is Leamington, 53 km away.

Topography around Chatham

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Chatham.

Within 3 km, the terrain around Chatham has only modest variations in elevation — a maximum elevation change of 27 m around an average of 182 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 62 m; within 80 km, only modest variations in elevation — a maximum elevation change of 159 m.

The land around Chatham is covered by artificial surfaces (34%), trees (26%) and cropland (25%) within 3 km, cropland (88%) within 16 km, and water (44%) and cropland (36%) within 80 km.

3 km
27 m
16 km
62 m
80 km
159 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Leamington 53 km · Kingsville 57 km · Tecumseh 58 km · Saint Clair Shores 59 km · Grosse Pointe Woods 59 km · Mount Clemens 60 km · Roseville 62 km · Clinton Township 63 km

Canada travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 83% of US
price level, 2025
GDP per capita
$55,698
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
2
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 53%none 35%Muslim 5%Hindu 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 Chatham (42.4122°, -82.1849°, elevation 183 m), 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).