Weather in Paris in September

Prime time. If you get to pick your dates, September is the one. Highs average 21.7 °C, lows 10.7 °C, and rain falls on 9 days — nothing in the month is working against you.

September is the highest-scoring month of the twelve. The nearest rival is July, and the month at the other end of the year is January.

Rain on 9 days, 1 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

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average September reaches 30 °C. Across the twenty years measured, the hottest September day reached 33.2 °C and the coldest night fell to 3.1 °C, and the wettest single day dropped 27 mm — roughly 64% of the month's rain in one day.

September is moderately variable: 13 mm in the driest year against 88 mm in the wettest, around an average of 42 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 9.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 76%, high enough to notice on the warm days without dominating them.

How September sits in the year

The month is on the way down: 3.2 °C cooler than August, with October dropping another 4.6 °C. The first week and the last are not the same trip.

Daylight in September

12.7 hours of daylight, losing 1.8 hours across the month. That is between Paris's extremes of 16.1 and 8.3 hours, so days are long enough not to constrain the plan.

An inland climate

Despite being inland, the year stays fairly even: 24.4 °C between the year's warmest afternoons and coldest nights.

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 Paris versus nearby

If Paris is one option among several, the nearby comparison is worth making. Le Havre is close enough to be a coin toss — 2.7 °C cooler, 1 day more rain. Lille is close enough to be a coin toss — within a degree on temperature, 2 days more rain.

So: September is the answer for Paris. If it is booked out or priced out, July is the next best thing at 3 points behind, and January is the month to keep off the shortlist.

Every month in Paris

See all twelve months in Paris, or where else to go in September.