Milton weather in September

In September, Milton sees average daytime highs of 21°C and overnight lows near 11°C, with 74 mm of rain across 9.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 24°C in the first days to 18°C by the end. The sky is clear or mostly clear about 33% 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 Milton's 3rd-clearest and 9th-windiest month. For the whole year in context, see Milton's year-round climate.

Daytime high
21°
4th warmest
Overnight low
11°
9th coldest
Rainfall
74 mm
9.1 wet days
Daylight
12 h 18 min
6:05 AM – 6:23 PM
Cloud cover
56%
3rd clearest
Wind
11 km/h
9th windiest
Solar energy
4.12 kWh/m²
Travel score
6.6
out of 10

Milton is town in Halton Region, Ontario, Canada.

Density
363/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 24°C in the first days to 18°C by the end.

A typical September day in Milton reaches about 21°C in the afternoon and slips back to 11°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 16°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)
12414
22414
32414
42314
52313
62313
72313
82313
92313
102212
112212
122212
132212
142212
152111
162111
172111
182111
192111
202010
212010
222010
232010
241910
25199
26199
27199
28189
29189
30188

How September really feels in Milton

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.

Milton weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -9°6310.28.39.10.0
Feb-0° / -9°5286.510.20.0
Mar / -4°619.5511.60.4
Apr12° / 8411.52.213.23.0
May18° / 8311.2014.55.6
Jun24° / 13°8811.8015.26.5
Jul26° / 16°8110.8014.96.6
Aug25° / 15°729.5013.86.9
Sep21° / 11°749.1012.36.6
Oct14° / 7610.90.210.84.0
Nov / -0°709.92.89.50.9
Dec / -5°62106.58.80.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 49%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15644
25545
35545
45545
55545
65545
75545
85446
95446
105347
115248
125248
135248
145149
155149
165149
175149
185149
195149
205050
215050
224951
234951
244951
254852
264852
274753
284654
294654
304555

Chance of precipitation in September

Any precipitation

Milton gets around 74 mm of rain over 9.1 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 36% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
128
229
329
430
530
631
731
831
931
1031
1130
1230
1330
1429
1529
1628
1728
1828
1928
2028
2128
2229
2330
2431
2532
2633
2734
2835
2935
3036

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 60% of days. Sticky, muggy-or-worse air turns up on roughly 6% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1382820131
2402720121
3412719121
4432718111
5452617111
6462617101
7482516101
849251691
951241591
1052241581
1153231581
1255231471
1356231470
1458221460
1558221460
1661211350
1761211350
1863201340
1964191340
2066191230
2167181230
2269171130
2371161120
2472161020
2573151020
267515910
277614910
287714810
297813810
308012710

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812calm
2912light breeze
3012light 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 5:48 AM to 6:21 AM, and sunset from 6:51 PM to 5:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:486:51
213.05:496:49
312.95:506:47
412.95:516:45
512.85:526:43
612.85:546:42
712.75:556:40
812.75:566:38
912.65:576:36
1012.65:586:34
1112.55:596:32
1212.56:006:30
1312.46:026:28
1412.46:036:26
1512.36:046:25
1612.36:056:23
1712.26:066:21
1812.26:076:19
1912.16:096:17
2012.16:106:15
2112.06:116:13
2212.06:126:11
2311.96:136:09
2411.96:146:07
2511.86:166:06
2611.86:176:04
2711.76:186:02
2811.76:196:00
2911.66:205:58
3011.66:215:56

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.12 kWh/m².

For context, solar energy here swings from a low near 1.32 kWh/m² to a high of 6.25 kWh/m² in June across the year — September's 4.12 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.6Bright
44.6Bright
54.5Bright
64.5Bright
74.5Bright
84.4Bright
94.4Bright
104.3Bright
114.3Bright
124.2Bright
134.2Bright
144.2Bright
154.1Bright
164.1Bright
174.0Bright
184.0Bright
194.0Moderate
203.9Moderate
213.9Moderate
223.8Moderate
233.8Moderate
243.7Moderate
253.7Moderate
263.6Moderate
273.6Moderate
283.5Moderate
293.5Moderate
303.5Moderate
Planning a trip in September

Is September a good time to visit Milton?

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

6.6
Sightseeing
2nd-best month of the year
4.1
Beach & pool
4th-best month of the year

September is a reasonable time to visit Milton for sightseeing.

What to pack for Milton in September

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

In September, Milton sees daytime highs around 21°C and nights near 11°C. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near Milton in September

The nearest coast averages about 19°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 26 km away) is warmest in August at about 21°C and coldest in February near 3°C.

It's comfortable for a long swim from Jul 22 to Sep 1 — about 1.4 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan4Bracing
Feb3Bracing
Mar3Bracing
Apr4Bracing
May8Bracing
Jun15Cool
Jul20Cool
Aug21Refreshing
Sep19Cool
Oct13Bracing
Nov8Bracing
Dec5Bracing

UV index in Milton in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Milton peaks around June 22 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 22UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5High
May6High
Jun8Very high
Jul8Very high
Aug7High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Milton 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 Milton is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (November, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1515 µg/m³Nov 218 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar13Moderate
Apr13Moderate
May14Moderate
Jun15Moderate
Jul16Moderate
Aug14Moderate
Sep13Moderate
Oct8Good
Nov8Good
Dec8Good
Location & terrain

Where is Milton?

Milton sits at 43.5°N, 79.9°W, 195 m above sea level, in Canada. The nearest listed city is Halton Hills, 14 km away.

Topography around Milton

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

Within 3 km, the terrain around Milton has only modest variations in elevation — a maximum elevation change of 132 m around an average of 208 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 297 m; within 80 km, significant variations in elevation — a maximum elevation change of 461 m.

The land around Milton is covered by artificial surfaces (51%) and trees (25%) within 3 km, trees (39%) and cropland (24%) within 16 km, and cropland (37%) and trees (25%) within 80 km.

3 km
132 m
16 km
297 m
80 km
461 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Halton Hills 14 km · Burlington 15 km · Georgetown 15 km · Oakville 18 km · Mississauga 19 km · Waterdown 20 km · Brampton 21 km · Etobicoke 29 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 Milton (43.5168°, -79.8829°, elevation 195 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. 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).