Weather in Markham - 14-day forecast

Detailed weather forecast for Markham, Canada: daytime and night temperature, rain, sunrise and sunset - today and for the next two weeks.

Forecast for the next days in Markham

today☀️ 22°💧 4.5 mm

Sun🌤️ 22°💧 11.7 mm

Mon☀️ 25°💧 0.7 mm

Tue☁️ 24°💧 3.4 mm

Wed🌧️ 27°💧 1.3 mm

Thu☁️ 15°💧 9.5 mm

Fri☀️ 18°💧 3.9 mm

Sat🌤️ 22°💧 1.1 mm

Forecast vs 1991-2020 climate normal

How does the current forecast compare with normal?

We compare the coming days with weather usually observed at this time of year.

NASA POWER

Thursday 10 Sept in Markham, the forecast high is 15°C. Typical daytime temperatures at this time of year range from 20°C to 27°C, so it will be exceptionally cool. It is cooler than 97% of similar days.

Saturday 5 Sept

22°Ccooler than usual

usually 21°C–28°C

cooler than 74% of similar days

night: exceptionally warm rain: more rain than usual wind: lighter than usual

Sunday 6 Sept

22°Ccooler than usual

usually 21°C–28°C

cooler than 76% of similar days

night: warmer than usual rain: exceptionally wet wind: exceptionally light

Monday 7 Sept

25°Cnear normal

usually 21°C–28°C

night: exceptionally warm rain: typical rainfall wind: exceptionally light

Tuesday 8 Sept

24°Cnear normal

usually 20°C–28°C

night: exceptionally warm rain: more rain than usual wind: lighter than usual

Wednesday 9 Sept

27°Cwarmer than usual

usually 20°C–27°C

warmer than 78% of similar days

night: exceptionally warm rain: typical rainfall wind: stronger than usual

Thursday 10 Sept

15°Cexceptionally cool

usually 20°C–27°C

cooler than 97% of similar days

night: near normal rain: exceptionally wet wind: stronger than usual

Friday 11 Sept

18°Cexceptionally cool

usually 20°C–27°C

cooler than 91% of similar days

night: near normal rain: more rain than usual wind: lighter than usual

How warm was this week in previous years?

Each bar shows the average daily high during the same 7-day period in each year.

swipe to see more years →

cooler yearstypical rangewarmer years2026 forecastcurrent forecast

From 1981 to 2025, the 5-11 Sept period averaged 24°C by day. The coolest year was 1993 (19°C) and the warmest was 2002 (29°C). The current forecast averages 22°C - lower than in 80% of historical years.

Historical reference: NASA POWER daily gridded data (MERRA-2), the 1991-2020 normal and a +/- 7-day calendar window. The typical range is the 20th-80th percentile. This is not a city weather-station reading and does not change the current forecast. NASA POWER Daily API.

14-day forecast - Markham

Markham - 14-day weather forecast infographic

Markham 30 & 45-day weather - long-range outlook

Next 15 days · forecast

24°

around 17° at night · days with rain: 11

Weeks 3-4 · avg for September

23°

around 12° at night · rain chance 35%

Weeks 5-7 · avg for October

15°

around 6° at night · rain chance 57%

The 30 & 45-day outlook for Markham: the next 15 days are a numerical forecast updated daily - on average 24° by day and 17° at night. Further out we rely on multi-year climate averages: around 23° in September, and about 15° in October. Forecasts beyond two weeks are indicative only.

Day-by-day forecast for Markham

Saturday5 September 2026

☀️22°clear sky

sunrise 06:45 · sunset 19:46 · night 18° · evening 21° · rain 4.5 mm · humidity 48% · wind 4 m/s · clouds 6%

Sunday6 September 2026

🌤️22°scattered clouds

sunrise 06:46 · sunset 19:44 · night 16° · evening 20° · rain 11.7 mm · humidity 53% · wind 3 m/s · clouds 26%

Monday7 September 2026

☀️25°clear sky

sunrise 06:47 · sunset 19:43 · night 18° · evening 22° · rain 0.66 mm · humidity 39% · wind 2 m/s · clouds 8%

Tuesday8 September 2026

☁️24°overcast clouds

sunrise 06:48 · sunset 19:41 · night 19° · evening 19° · rain 3.42 mm · humidity 43% · wind 3 m/s · clouds 100%

Wednesday9 September 2026

🌧️27°light rain

sunrise 06:49 · sunset 19:39 · night 18° · evening 23° · rain 1.29 mm · humidity 65% · wind 7 m/s · clouds 99%

Thursday10 September 2026

☁️15°overcast clouds

sunrise 06:50 · sunset 19:37 · night 11° · evening 14° · rain 9.51 mm · humidity 59% · wind 7 m/s · clouds 100%

Friday11 September 2026

☀️18°clear sky

sunrise 06:51 · sunset 19:35 · night 11° · evening 14° · rain 3.87 mm · humidity 35% · wind 4 m/s · clouds 99%

Saturday12 September 2026

🌤️22°a few clouds

sunrise 06:53 · sunset 19:33 · night 15° · evening 16° · rain 1.11 mm · humidity 42% · wind 4 m/s · clouds 21%

Sunday13 September 2026

🌧️28°light rain

sunrise 06:54 · sunset 19:32 · night 23° · evening 25° · rain 1.2 mm · humidity 35% · wind 5 m/s · clouds 69%

Monday14 September 2026

🌧️33°light rain

sunrise 06:55 · sunset 19:30 · night 26° · evening 28° · rain 0.51 mm · humidity 45% · wind 4 m/s · clouds 71%

Tuesday15 September 2026

🌧️34°light rain

sunrise 06:56 · sunset 19:28 · night 27° · evening 29° · rain 0.15 mm · humidity 35% · wind 4 m/s · clouds 28%

Wednesday16 September 2026

🌧️34°light rain

sunrise 06:57 · sunset 19:26 · night 25° · evening 27° · rain 1.35 mm · humidity 36% · wind 3 m/s · clouds 4%

Thursday17 September 2026

🌧️33°light rain

sunrise 06:58 · sunset 19:24 · night 18° · evening 22° · rain 1.53 mm · humidity 42% · wind 7 m/s · clouds 74%

Friday18 September 2026

☁️13°overcast clouds

sunrise 06:59 · sunset 19:22 · night 9° · evening 11° · rain 28.62 mm · humidity 45% · wind 7 m/s · clouds 86%

Saturday19 September 2026

🌤️12°scattered clouds

sunrise 07:00 · sunset 19:20 · night 5° · evening 8° · humidity 33% · wind 5 m/s · clouds 34%

UV index in Markham - is it safe to sunbathe?

Today the UV index in Markham is 6 (moderate) - unprotected fair skin can burn in about 35 minutes. Seek shade around midday. SPF 30+, sunglasses and a hat for longer stays.

Markham weather through the year

Warmest, driest months on average: April, May, June, July.

Upcoming public holidays in Canada: Labour Day — 7 September · National Day for Truth and Reconciliation — 30 September · Thanksgiving — 12 October.

Nearby and related places

TorontoMississaugaGatineauMontrealCalgaryOttawaVancouver

FAQ - Markham weather

What is the weather like in Markham today?

Today it is about 22° during the day and 18° at night, clear sky.

How far ahead can I check the forecast for Markham?

This page shows a detailed 14-day forecast plus the long-term monthly climate, so you can plan both a short trip and a holiday months ahead.