Climate averages 1991–2020
Newmarket weather
in September.
A mild, moderately wet month: the 4th warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Newmarket: daytime highs average 20.8°C and nights cool to about 12.2°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 73 mm of rain on roughly 9 days, which makes September a moderately wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 34 min on an average September day.
The nearest other city in this atlas is Richmond Hill (20 km away). In September its highs average 20.9°C, about as warm as Newmarket, with 69 mm of rain.
Among the 86 cities listed in Canada, Newmarket ranks joint 23rd of 86 for the warmest September highs and joint 22nd of 86 for the driest September (rainfall, lowest first). The mean September high of those 86 cities is 19.8°C; Newmarket is 1.0°C warmer than that mean.
From September to October, average highs fall by 7.3°C to 13.5°C, and monthly rainfall rises from 73 mm to 75 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Newmarket climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -2.6°C-11.3°C | -11.3°C | 57 | 10.1 | 9.39 h |
| February | -1.6°C-11.3°C | -11.3°C | 47 | 8.0 | 10.410 h |
| March | 3.7°C-6.0°C | -6.0°C | 56 | 10.1 | 11.912 h |
| April | 11.0°C1.0°C | 1.0°C | 77 | 11.4 | 13.413 h |
| May | 18.4°C7.9°C | 7.9°C | 80 | 11.2 | 14.715 h |
| June | 23.4°C13.7°C | 13.7°C | 88 | 11.2 | 15.415 h |
| July | 25.8°C16.5°C | 16.5°C | 84 | 10.7 | 15.115 h |
| August | 24.7°C15.9°C | 15.9°C | 78 | 9.6 | 14.014 h |
| September, selected | 20.8°C12.2°C | 12.2°C | 73 | 9.1 | 12.613 h |
| October | 13.5°C6.0°C | 6.0°C | 75 | 11.0 | 11.011 h |
| November | 6.3°C-0.4°C | -0.4°C | 68 | 10.2 | 9.710 h |
| December | 0.5°C-6.4°C | -6.4°C | 57 | 9.9 | 9.09 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Richmond Hill in SeptemberCanada · 20 kmHigh 20.9°C · Low 12.7°C · 69 mm rain
- Vaughan in SeptemberCanada · 24 kmHigh 21.0°C · Low 13.0°C · 69 mm rain
- Markham in SeptemberCanada · 26 kmHigh 21.1°C · Low 13.3°C · 81 mm rain
- Thornhill in SeptemberCanada · 26 kmHigh 21.0°C · Low 13.7°C · 69 mm rain
- Pickering in SeptemberCanada · 31 kmHigh 20.3°C · Low 13.5°C · 78 mm rain
- Toronto in SeptemberCanada · 39 kmHigh 20.8°C · Low 14.2°C · 69 mm rain
- Ajax in SeptemberCanada · 41 kmHigh 21.0°C · Low 14.3°C · 85 mm rain
- Barrie in SeptemberCanada · 42 kmHigh 20.1°C · Low 12.2°C · 80 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Newmarket) is explained once on the Newmarket year overview and on the Sources, method and limits page.