Weather in Milan in September
Italy · 20-year averages, September
Prime time. September is about as good as Milan gets. Highs average 24.7 °C, lows 14.9 °C, and rain falls on 10 days — nothing in the month is working against you.
September is the highest-scoring month of the twelve. The nearest rival is October, and the month at the other end of the year is December.
Rain on 10 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.
What the averages hide
The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest September day reached 33 °C and the coldest night fell to 6.6 °C, and the wettest single day dropped 46 mm — roughly 57% of the month's rain in one day.
September is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest September on record still delivered 139 mm against 26 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 80 mm average is a reasonable planning figure, not a promise.
Wind is light at 4.3 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 69%.
How September sits in the year
The month is on the way down: 4.4 °C cooler than August, with October dropping another 5.3 °C. The first week and the last are not the same trip.
Daylight in September
12.6 hours of daylight, losing 1.6 hours across the month. That is between Milan's extremes of 15.7 and 8.7 hours, so days are long enough not to constrain the plan.
An inland climate
With no coast nearby, the year swings a fair way — 28.8 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.
How busy it gets
Peak season. Expect the highest prices of the year and to be booking well ahead.
Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.
September in Milan versus nearby
If Milan is one option among several, the nearby comparison is worth making. Genoa is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Zermatt is the weaker option in September — 9.6 °C cooler, 3 days more rain.
So: September is the answer for Milan. If it is booked out or priced out, October is the next best thing at 2 points behind, and December is the month to keep off the shortlist.
Every month in Milan
| Month | High °C | Low °C | Rain days | Rain mm | Humidity % | Daylight h | Score |
|---|---|---|---|---|---|---|---|
| January | 7.6 | 0.5 | 7 | 47 | 77 | 9.1 | 48 |
| February | 9.7 | 1.4 | 7 | 62 | 75 | 10.4 | 48 |
| March | 14.5 | 4.6 | 9 | 64 | 72 | 11.8 | 65 |
| April | 18.5 | 8.5 | 11 | 87 | 72 | 13.5 | 75 |
| May | 22.5 | 12.6 | 14 | 106 | 71 | 14.9 | 73 |
| June | 26.7 | 17 | 12 | 81 | 70 | 15.7 | 77 |
| July | 29.3 | 19.3 | 11 | 68 | 65 | 15.4 | 69 |
| August | 29.1 | 19.1 | 12 | 89 | 66 | 14.2 | 67 |
| September | 24.7 | 14.9 | 10 | 80 | 69 | 12.6 | 80 |
| October | 19.4 | 10.6 | 10 | 95 | 76 | 11 | 78 |
| November | 13.2 | 5.9 | 11 | 137 | 80 | 9.6 | 55 |
| December | 8.1 | 1.6 | 9 | 69 | 77 | 8.7 | 45 |
See all twelve months in Milan, or where else to go in September.
Planning the rest of the trip
- Flight time to Milan how long you are actually in the air
- Milan time zone and the difference from home
- Days until your trip count down to the departure date