Québec weather in September

In September, Québec has daytime highs averaging 19 °C, nights around 11 °C, with 11 wet days. Figures are 1991–2020 climate normals.

  1. Jan -11°
  2. Feb -9°
  3. Mar -4°
  4. Apr
  5. May 12°
  6. Jun 17°
  7. Jul 20°
  8. Aug 19°
  9. Sep 15°
  10. Oct
  11. Nov
  12. Dec -7°

Daily temperatures through September

15°24°18152229
Daily highDaily low Day of month on the horizontal axis. Highs peak at 21.8 °C and lows bottom out at 7.5 °C.

How September develops

Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.

DaysAvg highAvg lowChance of rain
1–10 September21.2 °C12.6 °C34 %
11–20 September19.1 °C10.7 °C37 %
21–30 September17.2 °C9.0 °C40 %
0%50%100%151015202530
Chance of a wet day (over 1 mm) by date in September. Wettest date over the 30 years: September 29, at 57 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical September Share of the month
Days above 25 °C 2.3 of 30 8 %
Days above 30 °C 0.1 of 30 0 %
Days below 0 °C 0.07 of 30 0 %
Days with more than 1 mm rain 11 of 30 37 %

Conditions in September

MeasureAverage
Mean temperature 15 °C
Record high (1991–2020) 31 °C
Record low (1991–2020) -0.4 °C
Relative humidity 76 %
Wind speed 16 km/h
Cloud cover 59 %

Where Québec ranks in September

RankingPositionValue
The coolest places in North America in September12thof 5019 °C

September compared with the months around it

Month Avg high Rainfall Cloud
July 24.5 °C 126 mm 60 %
August 23.4 °C 114 mm 58 %
September 19.1 °C 110 mm 59 %
October 11.5 °C 126 mm 66 %
November 4.0 °C 97 mm 69 %

See all twelve months for Québec

Nearby destinations in September

Destination Avg high Wet days
Québec 19 °C 11
Longueuil 21 °C 10
Montréal 19 °C 10
Laval 21 °C 10

QuestionsSeptember in Québec, answered

How warm is Québec in September?

Daily highs average 19 °C and nights fall to about 11 °C, a spread of 8.4 °C between afternoon and dawn. That makes September the 4th warmest month of the year here.

Does it rain much in Québec in September?

September averages 110 mm of rain, spread over about 11 of the 30 days — 37 % of the month. Cloud cover averages 59 % of the sky.

How long are the days in September?

Québec averages 13 hours between sunrise and sunset in September. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.

Data sources and method

Normal period
1991–2020
Dataset version
era5-1991-2020-scores1.1
Last processed

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.