Climate averages 1991–2020
Markham weather
in September.
A mild, moderately wet month: the 4th warmest and the joint 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Markham: daytime highs average 21.1°C and nights cool to about 13.3°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 81 mm of rain on roughly 9 days, which makes September a moderately wet month (the joint 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 33 min on an average September day.
The nearest other city in this atlas is Pickering (11 km away). In September its highs average 20.3°C, 0.7°C cooler than Markham, with 78 mm of rain.
Among the 86 cities listed in Canada, Markham ranks joint 16th of 86 for the warmest September highs and 40th of 86 for the driest September (rainfall, lowest first). The mean September high of those 86 cities is 19.8°C; Markham is 1.3°C warmer than that mean.
From September to October, average highs fall by 7.1°C to 14.0°C, and monthly rainfall rises from 81 mm to 91 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
Markham climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -1.7°C-9.5°C | -9.5°C | 81 | 11.8 | 9.39 h |
| February | -0.9°C-9.7°C | -9.7°C | 59 | 8.7 | 10.410 h |
| March | 3.9°C-4.8°C | -4.8°C | 68 | 9.9 | 11.912 h |
| April | 10.7°C1.7°C | 1.7°C | 92 | 11.0 | 13.413 h |
| May | 17.5°C8.2°C | 8.2°C | 78 | 10.4 | 14.715 h |
| June | 22.8°C14.1°C | 14.1°C | 77 | 10.2 | 15.415 h |
| July | 25.7°C17.2°C | 17.2°C | 68 | 9.6 | 15.115 h |
| August | 24.9°C16.9°C | 16.9°C | 67 | 8.9 | 14.014 h |
| September, selected | 21.1°C13.3°C | 13.3°C | 81 | 9.0 | 12.613 h |
| October | 14.0°C7.1°C | 7.1°C | 91 | 11.9 | 11.011 h |
| November | 7.0°C0.9°C | 0.9°C | 88 | 11.2 | 9.710 h |
| December | 1.5°C-4.8°C | -4.8°C | 81 | 12.1 | 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
- Pickering in SeptemberCanada · 11 kmHigh 20.3°C · Low 13.5°C · 78 mm rain
- Richmond Hill in SeptemberCanada · 14 kmHigh 20.9°C · Low 12.7°C · 69 mm rain
- Thornhill in SeptemberCanada · 14 kmHigh 21.0°C · Low 13.7°C · 69 mm rain
- Ajax in SeptemberCanada · 19 kmHigh 21.0°C · Low 14.3°C · 85 mm rain
- Vaughan in SeptemberCanada · 19 kmHigh 21.0°C · Low 13.0°C · 69 mm rain
- Toronto in SeptemberCanada · 21 kmHigh 20.8°C · Low 14.2°C · 69 mm rain
- Newmarket in SeptemberCanada · 26 kmHigh 20.8°C · Low 12.2°C · 73 mm rain
- Whitby in SeptemberCanada · 27 kmHigh 21.0°C · Low 14.5°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 Markham) is explained once on the Markham year overview and on the Sources, method and limits page.