Norwalk, California

You are in the transition zone, where cool- and warm-season lawns both grow. These answers assume a cool-season lawn — ryegrass, fescue or bluegrass.

Best weekend slot

Saturday 8am–1pm

Verdict: Good

no rain in the record, ground firm

Next mow

Today 7pm–8pm

Verdict: Good

no rain in the record, ground firm

How you feel about mowing

Sensible middle ground.

Petrol or battery. The baseline.

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 27.9°C cooling to 0.0°C

Tuesday 1 September: Good. 7pm–8pm — no rain in the record, ground firm

Tuesday 1 September · 7pm–8pmConfident

7pm–8pm — no rain in the record, ground firm

Good:Grass wetness
Grass dryno rain in the record
Good:Ground firmness
Ground firm0mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.81
Good:Temperature
Temperature23°C
Good:Wind
Wind light12 km/h
Sociable hours
A bit early or late, but fine

Limiting factor:none

Wednesday 2 September: Good. 8am–2pm — no rain in the record, ground firm

Wednesday 2 September · 8am–2pmConfident

8am–2pm — no rain in the record, ground firm

Good:Grass wetness
Grass dryno rain in the record
Good:Ground firmness
Ground firm0mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.94
Marginal:Temperature
Temperature15°C
Good:Wind
Wind light4 km/h
Sociable hours
A bit early or late, but finestarts once the dew has burnt off

Limiting factor:none

Thursday 3 September: Good. 8am–8pm — no rain in the record, ground firm

Thursday 3 September · 8am–8pmConfident

8am–8pm — no rain in the record, ground firm

Good:Grass wetness
Grass dryno rain in the record
Good:Ground firmness
Ground firm0mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.95
Marginal:Temperature
Temperature16°C
Good:Wind
Wind light5 km/h
Sociable hours
A bit early or late, but finestarts when it stops being antisocial

Limiting factor:none

Friday 4 September: Good. 8am–8pm — no rain in the record, ground firm

Friday 4 September · 8am–8pmConfident

8am–8pm — no rain in the record, ground firm

Good:Grass wetness
Grass dryno rain in the record
Good:Ground firmness
Ground firm0mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.75
Marginal:Temperature
Temperature21°C
Good:Wind
Wind light10 km/h
Sociable hours
A bit early or late, but finestarts when it stops being antisocial

Limiting factor:none

Saturday 5 September: Good. 8am–1pm — no rain in the record, ground firm

Saturday 5 September · 8am–1pmReasonably confident

8am–1pm — no rain in the record, ground firm

Good:Grass wetness
Grass dryno rain in the record
Good:Ground firmness
Ground firm0mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.65
Marginal:Temperature
Temperature22°C
Good:Wind
Wind light5 km/h
Sociable hours
A bit early or late, but finestarts when it stops being antisocial

Limiting factor:none

Sunday 6 September: Good. 10am–midday — heat stress — 28°C

Sunday 6 September · 10am–middayReasonably confident

10am–midday — heat stress — 28°C

Good:Grass wetness
Grass drydried off since a shower 0 hours ago
Good:Ground firmness
Ground firm0mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.54
Poor:Temperature
Cool25°C
Good:Wind
Wind light3 km/h
Sociable hours
Fine by the neighboursstarts when it stops being antisocial

Limiting factor:temperature

Monday 7 September: Good. 5pm–8pm — heat stress — 28°C

Monday 7 September · 5pm–8pmReasonably confident

5pm–8pm — heat stress — 28°C

Good:Grass wetness
Grass drydried off since a shower 0 hours ago
Good:Ground firmness
Ground firm1mm rain over the last week
Marginal:Growth
Growing slowlygrowth potential 0.34
Poor:Temperature
Cool26°C
Good:Wind
Wind light2 km/h
Sociable hours
A bit early or late, but fine

Limiting factor:temperature

Tuesday 8 September: Good. 8am–10am — growing slowly — growth potential 0.31

Tuesday 8 September · 8am–10amReasonably confident

8am–10am — growing slowly — growth potential 0.31

Good:Grass wetness
Grass dryrain earlier today
Good:Ground firmness
Ground firm3mm rain over the last week
Marginal:Growth
Growing slowlygrowth potential 0.31
Poor:Temperature
Heat stress26°C
Good:Wind
Wind light3 km/h
Sociable hours
A bit early or late, but finestarts when it stops being antisocial

Limiting factor:growth

Wednesday 9 September: Not worth it. No — ground frozen.

Wednesday 9 SeptemberLow confidence this far out

No — ground frozen.

Good:Grass wetness
Grass dryno rain since Monday
Good:Ground firmness
Ground firm3mm rain over the last week
Marginal:Growth
Growing slowlygrowth potential 0.24
Poor:Temperature
Cool26°C
Good:Wind
Wind light8 km/h

Limiting factor:growth

Thursday 10 September: Not worth it. No — ground frozen.

Thursday 10 SeptemberLow confidence this far out

No — ground frozen.

Good:Grass wetness
Grass dryno rain since Monday
Good:Ground firmness
Ground firm3mm rain over the last week
Marginal:Growth
Growing slowlygrowth potential 0.29
Poor:Temperature
Cool25°C
Good:Wind
Wind light8 km/h

Limiting factor:growth

Soil temperature

82°F27.9°C

at 6cm — germination depth

Cooling over the next 11 days.

Too warm to seed — the soil is heat-stressed. Wait for it to cool.

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.
SpeciesSoil tempDays
Perennial ryegrass8°C5–10
Red / chewings fescue8–10°C10–14
Tall fescuelikely yours10–12°C10–14
Browntop bentColonial bentgrass10–12°C14–21
Smooth-stalked meadow grassKentucky bluegrasslikely yours12–13°C14–28

What this means right now

  • Warning: Too warm to seed

    Too warm to seed — the soil is heat-stressed. Wait for it to cool.

  • Warning: Heat stress

    Wednesday 2 September gets hot enough to stress the sward. Mow early or late, and raise the height.

  • Worth watching: Worth knowing

    You are in the transition zone, where cool- and warm-season lawns both grow. These answers assume a cool-season lawn — ryegrass, fescue or bluegrass.

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Forecast from Open-Meteo, refreshed hourly. Soil temperature is modelled, not measured — how that works and where the thresholds come from.