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Grenoble in September: Weather, Average temperature and Climate

Planning a trip and want to know what the weather in Grenoble in September will be like? Take a look at our weather guide for Grenoble, based on historical data.
Check flight prices to Grenoble on Avionero:
September

Weather in Grenoble in September 2025

OK Weather
Warm
🌧️
Rainy
If you plan to visit Grenoble in September, the weather is typically alright, with an average high temperature of +23°C during the day and approximately 6 sunny days. Expect some rainy, though, as there are typically 14 rainy days in the month and around 102 mm of precipitation. The weather is changeable so you may have to pack for every eventuality. Search flights in one click on Avionero.

Average weather

☀️
+23°C
Avg. max. temperature
+4°C
Min.
+34°C
Max.
102 mm
Total precipitation
78%
Avg. humidity
1 m/s
Avg. wind
6 ☀️
Sunny Days
10 ⛅️
Cloudy
14 🌦
Rainy
Our opinion: Grenoble has OK weather in September.

Average temperature in Grenoble in September

Here are the expected maximum, average and minimum temperatures in Grenoble for September based on the historical data.
Last Year
Historical Data

Going from a maximum of +33°C during the day to a minimum of +9°C during the night, the temperature in September averages around +27°C.

The average maximum temperature goes down 17% by the end of the month, compared with the beginning of the month, from +29°C to +25°C.

Is Grenoble warm or cold in September?

Grenoble is typically warm in September.

Maximum temperatures go down compared to the previous month from +27°C to +23°C. The minimum temperature also goes down from +16°C to +13°C.

It’s generally warm, but pack a long-sleeve shirt for evenings.

Take a look at how September is compared to other months in Grenoble:

Climate in Grenoble in September

Grenoble weather looks like this, on average, in September and the surrounding months.
AugustSeptemberOctober
Avg. temperature
+27°C+23°C+19°C
Min. temperature
+8°C+4°C-1°C
Max. temperature
+39°C+34°C+29°C
Rainfall
96 mm102 mm124 mm
Wind
1 m/s1 m/s1 m/s
Humidity
73%78%81%
Air pressure
1016 HPa1017 HPa1017 HPa
Sunny days
863
Cloudy days
81012
Rainy days
161415
Snowy days
000

September typically has worse weather conditions compared to August. It’s getting colder in September. From +27°C in the day, the average maximum temperature lowers to +23°C. Prepare for more rain. Average rainfall goes from 96 mm to 102 mm. Humidity rises from 73% to 78%. The average wind speed doesn’t change much during September, staying around 1 m/s. The days becoming less sunny, going from 8 sunny days in August to 6 in September.

October brings much the same weather, it remains ok.

Wind

Wind speed in Grenoble in September based on historical data.
Last Year
Historical Data

The average wind speed is 1 m/s getting up to 1 m/s which is a light breeze; barely moving the tree leaves.

The average wind speed in Grenoble is gradually increasing during September, going from 1 m/s to 1 m/s over the course of the month.

Rain

Amount of rainfall in mm during September in Grenoble based on historical data.
Last Year
Historical Data
Typically, there is a 30% chance of rain on an average day in September, with total rainfall of approximately 95 mm. The maximum amount of rainfall per day is around 38 mm, which is moderate rain. On average, there are about 9 rainy days during September, so prepare to bring an umbrella.
Here’s how September is compared with other months in the amount of precipitation, total mm:
Grenoble wettest month is May, where a typical day has a 68% chance of precipitation and 138 mm of rainfall per day. February, on the other hand, is the driest month with a mere 34% chance of precipitation and 85 mm of rainfall per day.

How was the weather last September in Grenoble?

This is the weather in Grenoble in September 2023:
1 September
☁️
+29°C
2 September
☁️
+29°C
3 September
☁️
+30°C
4 September
☀️
+33°C
5 September
☀️
+31°C
6 September
☀️
+30°C
7 September
☀️
+31°C
8 September
☀️
+31°C
9 September
☀️
+31°C
10 September
☀️
+31°C
11 September
☁️
+31°C
12 September
☁️
+29°C
13 September
🌧️
+22°C
14 September
☁️
+24°C
15 September
☁️
+27°C
16 September
🌧️
+23°C
17 September
☁️
+29°C
18 September
🌧️
+24°C
19 September
☀️
+24°C
20 September
☁️
+26°C
21 September
☁️
+23°C
22 September
🌧️
+20°C
23 September
☁️
+18°C
24 September
☀️
+22°C
25 September
☀️
+24°C
26 September
☀️
+26°C
27 September
☀️
+27°C
28 September
☀️
+27°C
29 September
☀️
+27°C
30 September
☀️
+25°C
In September 2023 Grenoble had 15 sunny days, 11 cloudy days, and 4 rainy days. The average maximum temperature was +27°C, with an absolute maximum of +33°C and a minimum of +18°C. The average humidity was 75%, with a maximum of 100% and a minimum of 43%. The average wind speed was 1 m/s, with a maximum of 7 m/s and a minimum of 0 m/s.
Are you planning a trip in September?

Climate Change over Years

This is how Grenoble climate have been changing during last 43 years period.

The climate in Grenoble in September has not changed much over the last 43 years.

The average temperature was the lowest in 1980 (+15°C) and the highest in 2022 (+20°C). The driest year was 1989 with only 836 mm of rainfall, and the wettest year was 2023 with 2113 mm.

FAQ

Frequently asked questions about the weather in Grenoble in September:

Is September a good time to visit Grenoble?

It’s always a good time to visit Grenoble, but the weather is changeable in September, so plan a mix of indoor and outdoor activities and exploring, and pack for every eventuality.

Can you sunbathe in Grenoble in September?

September is warm in Grenoble. You may enjoy some beach or pool time in the day, but pack something a tad warmer for the evening.

Is Grenoble rainy in September?

Grenoble is often rainy in September. You may get a bit damp when outside, so pack an umbrella, and maybe even a raincoat.

Is it sunny in Grenoble in September?

Usually, it’s not very sunny in Grenoble in September, often it’s pretty cloudy. Pack for any eventuality; layering can help reduce the number of bulky items needed.

Other cities in France

Check out the weather for other cities in France.

Monthly weather in Grenoble

Source of the data

For this page, we’ve looked at the typical weather in Grenoble, based on historical hourly weather data from January 1, 1979, to December 31, 2023.

For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.