What is the soil temperature in Toronto, Ontario?

Soil temperature at 6cm in Toronto, Ontario is currently 23.5°C. Seeding conditions are open — soil is 23.5°C at 6cm and holding above 12.5°C.

Soil temperature in Toronto, Ontario

Soil temperature

23.5°C74°F

at 6cm — germination depth

Cooling over the next 11 days.

Seeding conditions are open — soil is 23.5°C at 6cm and holding above 12.5°C.

Most cool-season lawns in the northern US and Canada are bluegrass, tall fescue, or a mix of the two. We assume that, and use12.5°C as the seeding threshold.

I know what grass I have

The differences are small. Ryegrass is the quickest off the mark; bluegrass is the slowest and wants the warmest soil. Everything else sits between.

Soil temperature at 6cm for reliable germination. Sources onthe method page.
Species	Soil temp	Days
Perennial ryegrass	8°C	5–10
Red / chewings fescue	8–10°C	10–14
Tall fescuelikely yours	10–12°C	10–14
Browntop bentColonial bentgrass	10–12°C	14–21
Smooth-stalked meadow grassKentucky bluegrasslikely yours	12–13°C	14–28

Soil temperature at 6cm in Toronto, Ontario is currently 23.5°C, and falling about 22.4°C over the next 11 days. That depth matters because it is where grass seed sits and where roots start working, and it lags air temperature by days — which is why a warm afternoon here tells you very little on its own.

Lawns in this area are typically Kentucky bluegrass with tall fescue, the usual mix for cool-season lawns at this latitude. That blend needs the soil to hold above 12.5°C before seed germinates reliably. Seeding conditions are open — soil is 23.5°C at 6cm and holding above 12.5°C.

7 of the next 10 days are good mowing days. The other 3 are held back by wet grass or soft ground. The best weekend slot right now is Sunday 10am–8pm, on the basis that ground soft in places — 10mm rain over the last week.

The next recommended window in Toronto opens at 2pm on Wednesday 2 September, because that is when the dew has burnt off — earlier than that and you are cutting wet grass. Underfoot, the ground reads as soft in places after 6mm rain over the last week.

See the full mowing forecast for Toronto

The next 10 days

Column height is how mowable the day is; the lighter band is the best stretch within it. The line is soil temperature at 6cm. It crosses the seeding threshold inside this forecast.

12.5°C — seeding

Soil at 6cm 22.5°C cooling to 0.0°C

Tuesday 1 SeptemberConfident

No — grass wet, rain earlier today.

Poor:Grass wetness: Grass wetrain earlier today
Good:Ground firmness: Ground soft in places6mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.97
Good:Temperature: Temperature20°C
Good:Wind: Wind light9 km/h

Limiting factor:grass wetness

Wednesday 2 September · 2pm–6pmConfident

2pm–6pm — grass dry — no rain since Monday

Poor:Grass wetness: Grass dryno rain since Monday
Good:Ground firmness: Ground soft in places7mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.97
Good:Temperature: Temperature20°C
Good:Wind: Wind light4 km/h
Sociable hours: Fine by the neighboursstarts once the dew has burnt off

Limiting factor:grass wetness

Thursday 3 September · 11am–3pmConfident

11am–3pm — grass dry — rain earlier today

Marginal:Grass wetness: Grass dryrain earlier today
Good:Ground firmness: Ground soft in places10mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.92
Marginal:Temperature: Temperature18°C
Good:Wind: Wind light7 km/h
Sociable hours: Fine by the neighboursstarts once the dew has burnt off

Limiting factor:grass wetness

Friday 4 September · 8am–8pmConfident

8am–8pm — ground soft in places — 10mm rain over the last week

Good:Grass wetness: Grass dryno rain since Wednesday
Good:Ground firmness: Ground soft in places10mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.98
Good:Temperature: Temperature17°C
Good:Wind: Wind light7 km/h
Sociable hours: A bit early or late, but finestarts when it stops being antisocial