Florence in September
What to expect
Florence is in early autumn during September, a shoulder-season stretch where conditions can nudge warmer or cooler week to week. It leans warmly comfortable through the day, and a gentle drop-off once the sun goes down. You get a comfortable daylight window for day trips and sightseeing. Conditions tend to feel steady, which makes planning simple.
September in context
How it compares to the rest of the year in Florence.
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 12.5 h
- UV index (max)
- 6
- Typical sun hours
- 05:54 - 18:24
Rain & Snow
- Total rain
-
- Rainy days
- 10 days
- Cloud cover (avg)
- 44%
Humidity & Wind
- Humidity (avg)
- 71%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for September. Typical high 24.3°C and low 15.6°C.
Typical disruptions in September
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in September.
Rain disruption Measures: Likely rain disruption days. Observed about 16% of days (4.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.8 days / month
~16% of days
Why this matters
- Expected days 4.8 days / month
- Probability ~16% of days
- Intensity Up to ~46mm (P95)
Rain disruption risk appears on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Washout risk Measures: Washout day risk. Observed about 15% of days (4.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.5 days / month
~15% of days
Why this matters
- Expected days 4.5 days / month
- Probability ~15% of days
- Intensity Up to ~47mm (P95)
Washout conditions are possible on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Stormy conditions Measures: Storm-impact proxy days. 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 ~78km/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.
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 2% of days (0.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.7 days / month
~2% of days
Why this matters
- Expected days 0.7 days / month
- Probability ~2% of days
- Intensity Up to ~79km/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.
Hot days Measures: Hot days (>=30C). Observed about 11% of days (3.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.4 days / month
~11% of days
Why this matters
- Expected days 3.4 days / month
- Probability ~11% of days
- Intensity Up to ~33°C (P95)
Hot days are possible on ~3 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 6% of days (1.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.8 days / month
~6% of days
Why this matters
- Expected days 1.8 days / month
- Probability ~6% of days
- Intensity Up to ~35°C (P95)
Feels-like heat >=32C is possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Show all disruptions (20 more)
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 10% of days (2.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.9 days / month
~10% of days
Why this matters
- Expected days 2.9 days / month
- Probability ~10% of days
- Intensity Up to ~52mm (P95)
Heavy rain is possible on ~3 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 3% of days (1.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.0 days / month
~3% of days
Why this matters
- Expected days 1.0 days / month
- Probability ~3% of days
- Intensity Up to ~59mm (P95)
Very heavy rain is possible on ~1 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 1.0 days/month in September. Historical risk signal only, not a day-by-day forecast.
1.0 days / month
Probability unavailable
Why this matters
- Expected days 1.0 days / month
- Probability —
- Intensity Up to ~35mm (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.
Extreme rain Measures: Extreme rain days (>=50mm). 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 ~66mm (P95)
Extreme rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Muggy days Measures: Muggy days (dew point >=20C). 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 ~21°C (P95)
Muggy conditions are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cold feels-like nights Measures: Cold feels-like nights (min <=5C). 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 ~5°C (P95)
Cold feels-like nights are possible on ~0 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Wet days Measures: Wet days (>=0.1mm). Observed about 41% of days (12.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
12.4 days / month
~41% of days
Why this matters
- Expected days 12.4 days / month
- Probability ~41% of days
- Intensity Up to ~34mm (P95)
Measurable rain is possible on ~12 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 32% of days (9.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
9.6 days / month
~32% of days
Why this matters
- Expected days 9.6 days / month
- Probability ~32% of days
- Intensity Up to ~21h (P95)
Several rainy hours are possible on ~10 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 32% of days (9.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
9.6 days / month
~32% of days
Why this matters
- Expected days 9.6 days / month
- Probability ~32% of days
- Intensity Up to ~98% (P95)
Cloudy skies are possible on ~10 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Gusty days Measures: Gusty days (>=40 km/h). Observed about 25% of days (7.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
7.5 days / month
~25% of days
Why this matters
- Expected days 7.5 days / month
- Probability ~25% of days
- Intensity Up to ~64km/h (P95)
Gusty conditions are possible on ~7 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 24% of days (7.1 days/month) in September. Historical risk signal only, not a day-by-day forecast.
7.1 days / month
~24% of days
Why this matters
- Expected days 7.1 days / month
- Probability ~24% of days
- Intensity Up to ~22h (P95)
Wet-most-of-day conditions are possible on ~7 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 22% of days (6.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
6.7 days / month
~22% of days
Why this matters
- Expected days 6.7 days / month
- Probability ~22% of days
- Intensity Up to ~92% (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 16% of days (4.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.8 days / month
~16% of days
Why this matters
- Expected days 4.8 days / month
- Probability ~16% of days
- Intensity Up to ~99% (P95)
Mostly cloudy skies are possible on ~5 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humid days Measures: Humid days (dew point >=18C). Observed about 7% of days (2.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.0 days / month
~7% of days
Why this matters
- Expected days 2.0 days / month
- Probability ~7% of days
- Intensity Up to ~20°C (P95)
Humid conditions are possible on ~2 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 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 ~100% (P95)
Overcast skies are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Convective risk Measures: Convective storm risk proxy. Observed about 3% of days (1.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.0 days / month
~3% of days
Why this matters
- Expected days 1.0 days / month
- Probability ~3% 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.
Heatwave run Measures: Heatwave runs (>=3 hot days). 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 ~33°C (P95)
Heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Fog-likely signal Measures: Fog-likely visibility proxy. 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 ~96% (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 (0.4 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 ~96 (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.
Feels-like heatwave Measures: Feels-like heatwave runs (>=3 days). Observed about 0.2 days/month in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
Probability unavailable
Why this matters
- Expected days 0.2 days / month
- Probability —
- Intensity Up to ~34°C (P95)
Feels-like heatwave runs 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 Florence?
Typical September days in Florence reach highs of 25°C (77°F) with nights around 15°C (59°F). It usually feels warm by day and cool after dark. Overall, September sits in the middle of the Florence climate range.
What are temperatures like in September?
In September, you can usually expect highs of 25°C (77°F) and lows near 15°C (59°F). That means warm days and cool nights, so pack layers you can add or remove.
How much does it rain in September?
Rainfall in September averages 94 mm (3.7 in) across roughly 10 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 13 hours of daylight in September. Sunrise is typically around 05:54 and sunset near 18:24. 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 7 km/h (4 mph), with gusts on the windiest days reaching about 49 km/h (30 mph). On the ground, it is it often feels breezy, especially in more exposed spots or along the coast.