What is the soil temperature in London, Ontario?

Soil temperature at 6cm in London, Ontario is currently 24.0°C. Seeding conditions are open — soil is 24.0°C at 6cm and holding above 12.5°C.

Soil temperature in London, Ontario

Soil temperature

24.0°C75°F

at 6cm — germination depth

Cooling over the next 11 days.

Seeding conditions are open — soil is 24.0°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 London, Ontario is currently 24.0°C, and falling about 23.5°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 24.0°C at 6cm and holding above 12.5°C.

7 of the next 10 days are good mowing days. The best weekend slot right now is Sunday 10am–8pm, on the basis that no rain since Friday, ground firm.

The next recommended window in London opens at 11am 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 firm after 23mm rain over the last week.

See the full mowing forecast for London

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 23.3°C cooling to 0.0°C

Tuesday 1 SeptemberConfident

No — cool, 25°C.

Good:Grass wetness: Grass dryno rain since Monday
Good:Ground firmness: Ground firm23mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.69
Marginal:Temperature: Cool24°C
Good:Wind: Wind light7 km/h

Limiting factor:temperature

Wednesday 2 September · 11am–2pmConfident

11am–2pm — grass dry — rain earlier today

Good:Grass wetness: Grass dryrain earlier today
Good:Ground firmness: Ground firm23mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.64
Marginal:Temperature: Temperature22°C
Good:Wind: Wind light9 km/h
Sociable hours: Fine by the neighboursstarts once the dew has burnt off

Limiting factor:grass wetness

Thursday 3 September · 8am–11amConfident

8am–11am — no rain since Wednesday, ground firm

Good:Grass wetness: Grass dryno rain since Wednesday
Good:Ground firmness: Ground firm24mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.84
Marginal:Temperature: Temperature19°C
Good:Wind: Wind light9 km/h
Sociable hours: A bit early or late, but finestarts once the dew has burnt off

Limiting factor:none

Friday 4 September · 4pm–8pmConfident

4pm–8pm — grass dry — rain earlier today

Poor:Grass wetness: Grass dryrain earlier today
Good:Ground firmness: Ground firm26mm rain over the last week
Good:Growth: Growing wellgrowth potential 1.00
Good:Temperature: Temperature16°C
Good:Wind: Wind light8 km/h
Sociable hours: Fine by the neighboursstarts once the dew has burnt off

Limiting factor:grass wetness

Saturday 5 September · 8am–8pmReasonably confident

8am–8pm — rain earlier today, ground firm

Good:Grass wetness: Grass dryrain earlier today
Good:Ground firmness: Ground firm34mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.91
Good:Temperature: Temperature13°C
Good:Wind: Wind light10 km/h
Sociable hours: A bit early or late, but finestarts when it stops being antisocial

Limiting factor:none

Sunday 6 September · 10am–8pmReasonably confident

10am–8pm — no rain since Friday, ground firm

Good:Grass wetness: Grass dryno rain since Friday
Good:Ground firmness: Ground firm34mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.85
Good:Temperature: Temperature12°C
Good:Wind: Wind light10 km/h
Sociable hours: Fine by the neighboursstarts when it stops being antisocial

Limiting factor:none

Monday 7 September · 8am–8pmReasonably confident

8am–8pm — no rain since Friday, ground firm

Good:Grass wetness: Grass dryno rain since Friday
Good:Ground firmness: Ground firm16mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.92
Good:Temperature: Temperature14°C
Good:Wind: Wind light8 km/h
Sociable hours: A bit early or late, but finestarts when it stops being antisocial

Limiting factor:none

Tuesday 8 September · 8am–8pmReasonably confident

8am–8pm — no rain since Friday, ground firm

Good:Grass wetness: Grass dryno rain since Friday
Good:Ground firmness: Ground firm12mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.97
Good:Temperature: Temperature16°C
Good:Wind: Wind light8 km/h
Sociable hours: A bit early or late, but finestarts when it stops being antisocial

Limiting factor:none

Wednesday 9 SeptemberLow confidence this far out

No — ground frozen.

Good:Grass wetness: Grass dryno rain since Friday
Good:Ground firmness: Ground firm12mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.88
Good:Temperature: Temperature13°C
Good:Wind: Wind light16 km/h

Limiting factor:none

Thursday 10 SeptemberLow confidence this far out

No — ground frozen.

Marginal:Grass wetness: Grass drydried off since a shower 0 hours ago
Good:Ground firmness: Ground firm11mm rain over the last week
Good:Growth: Growing wellgrowth potential 0.96
Good:Temperature: Temperature20°C
Good:Wind: Wind light19 km/h

Limiting factor:grass wetness

Nearby

Your own postcode

These are town-centre figures. Yours will differ a little.