Toronto in September
What to expect
In Toronto, September sits in early autumn, a shoulder-season month where the feel can shift as the season turns. Most days land in a mild, easygoing zone, with evenings that ease back comfortably. Comfort is usually predictable, so a standard day plan works well. Daylight is moderate, so steady pacing works well.
September in context
How it compares to the rest of the year in Toronto.
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 12.5 h
- UV index (max)
- 6
- Typical sun hours
- 05:57 - 18:26
Rain & Snow
- Total rain
-
- Rainy days
- 11 days
- Cloud cover (avg)
- 51%
Humidity & Wind
- Humidity (avg)
- 73%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for September. Typical high 19.8°C and low 12.9°C.
Typical disruptions in September
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in September.
Washout risk Measures: Washout day risk. Observed about 13% of days (3.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.9 days / month
~13% of days
Why this matters
- Expected days 3.9 days / month
- Probability ~13% of days
- Intensity Up to ~34mm (P95)
Washout conditions are possible on ~4 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 5% of days (1.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.4 days / month
~5% of days
Why this matters
- Expected days 1.4 days / month
- Probability ~5% of days
- Intensity Up to ~83km/h (P95)
Strong gusts are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Stormy conditions Measures: Storm-impact proxy days. Observed about 4% of days (1.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.3 days / month
~4% of days
Why this matters
- Expected days 1.3 days / month
- Probability ~4% of days
- Intensity Up to ~83km/h (P95)
Stormy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain disruption Measures: Likely rain disruption days. Observed about 15% of days (4.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.4 days / month
~15% of days
Why this matters
- Expected days 4.4 days / month
- Probability ~15% of days
- Intensity Up to ~29mm (P95)
Rain disruption risk appears on ~4 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cold feels-like nights Measures: Cold feels-like nights (min <=5C). Observed about 3% of days (0.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.9 days / month
~3% of days
Why this matters
- Expected days 0.9 days / month
- Probability ~3% of days
- Intensity Up to ~5°C (P95)
Cold feels-like nights are possible on ~1 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Muggy days Measures: Muggy days (dew point >=20C). Observed about 3% of days (0.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.9 days / month
~3% of days
Why this matters
- Expected days 0.9 days / month
- Probability ~3% of days
- Intensity Up to ~22°C (P95)
Muggy conditions are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Show all disruptions (20 more)
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 8% of days (2.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.4 days / month
~8% of days
Why this matters
- Expected days 2.4 days / month
- Probability ~8% of days
- Intensity Up to ~36mm (P95)
Heavy rain is possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Washout run Measures: Multi-day washout runs. Observed about 0.6 days/month in September. Historical risk signal only, not a day-by-day forecast.
0.6 days / month
Probability unavailable
Why this matters
- Expected days 0.6 days / month
- Probability —
- Intensity Up to ~47mm (P95)
Multi-day washout runs are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 1% of days (0.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.3 days / month
~1% of days
Why this matters
- Expected days 0.3 days / month
- Probability ~1% of days
- Intensity Up to ~49mm (P95)
Very heavy rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Severe gusts Measures: Severe gust days (>=80 km/h). Observed about 1% of days (0.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~91km/h (P95)
Severe gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 1% of days (0.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.3 days / month
~1% of days
Why this matters
- Expected days 0.3 days / month
- Probability ~1% of days
- Intensity Up to ~35°C (P95)
Feels-like heat >=32C is possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Wet days Measures: Wet days (>=0.1mm). Observed about 46% of days (13.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
13.9 days / month
~46% of days
Why this matters
- Expected days 13.9 days / month
- Probability ~46% of days
- Intensity Up to ~19mm (P95)
Measurable rain is possible on ~14 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 41% of days (12.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
12.3 days / month
~41% of days
Why this matters
- Expected days 12.3 days / month
- Probability ~41% of days
- Intensity Up to ~100% (P95)
Cloudy skies are possible on ~12 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Gusty days Measures: Gusty days (>=40 km/h). Observed about 35% of days (10.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
10.5 days / month
~35% of days
Why this matters
- Expected days 10.5 days / month
- Probability ~35% of days
- Intensity Up to ~69km/h (P95)
Gusty conditions are possible on ~10 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 32% of days (9.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
9.5 days / month
~32% of days
Why this matters
- Expected days 9.5 days / month
- Probability ~32% of days
- Intensity Up to ~17h (P95)
Several rainy hours are possible on ~10 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
High humidity Measures: High humidity days (RH >=80%). Observed about 24% of days (7.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
7.3 days / month
~24% of days
Why this matters
- Expected days 7.3 days / month
- Probability ~24% of days
- Intensity Up to ~90% (P95)
High humidity is possible on ~7 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 21% of days (6.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
6.4 days / month
~21% of days
Why this matters
- Expected days 6.4 days / month
- Probability ~21% of days
- Intensity Up to ~100% (P95)
Mostly cloudy skies are possible on ~6 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 20% of days (6.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
6.0 days / month
~20% of days
Why this matters
- Expected days 6.0 days / month
- Probability ~20% of days
- Intensity Up to ~19h (P95)
Wet-most-of-day conditions are possible on ~6 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Humid days Measures: Humid days (dew point >=18C). Observed about 9% of days (2.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.8 days / month
~9% of days
Why this matters
- Expected days 2.8 days / month
- Probability ~9% of days
- Intensity Up to ~22°C (P95)
Humid conditions are possible on ~3 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 8% of days (2.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.5 days / month
~8% of days
Why this matters
- Expected days 2.5 days / month
- Probability ~8% of days
- Intensity Up to ~100% (P95)
Overcast skies are possible on ~2 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Convective risk Measures: Convective storm risk proxy. Observed about 2% of days (0.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.6 days / month
~2% of days
Why this matters
- Expected days 0.6 days / month
- Probability ~2% of days
- Intensity Up to ~20°C (P95)
Convective risk signal appears on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 1% of days (0.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~28km/h (P95)
Breezy conditions are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Warm nights Measures: Warm nights (min >=22C). Observed about 1% of days (0.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.3 days / month
~1% of days
Why this matters
- Expected days 0.3 days / month
- Probability ~1% of days
- Intensity Up to ~23°C (P95)
Warm nights are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 1% of days (0.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~93% (P95)
Fog-likely conditions are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data Measures: Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data. Observed about 1% of days (0.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~93 (P95)
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data is possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Hot days Measures: Hot days (>=30C). Observed about 1% of days (0.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~32°C (P95)
Hot days are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Frequently asked questions
Is September a good time to visit Toronto?
Typical September days in Toronto reach highs of 21°C (70°F) with nights around 14°C (57°F). It usually feels mild by day and cool after dark. Overall, September sits in the middle of the Toronto climate range.
What are temperatures like in September?
Daytime temperatures in September typically peak near 21°C (70°F), while nights drop to around 14°C (57°F). Expect mild afternoons and cool evenings.
How much does it rain in September?
Rainfall in September averages 69 mm (2.7 in) across roughly 11 days. Overall it is a quite rainy time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in September?
You can expect about 12 hours of daylight in September. Sunrise is typically around 05:57 and sunset near 18:26. Daylight is fairly typical, with enough time for sightseeing.
How strong is the sun in September?
UV levels are often high (around 6). Regular sunscreen and a hat are recommended.
Is it windy in September?
In September, average wind speeds are around 12 km/h (7 mph), with gusts on the windiest days reaching about 54 km/h (34 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.