Swansea, Wales

Best weekend slot

Saturday 8am–5pm

Verdict: Good

ground soft — 59mm rain over the last week

Next mow

Tomorrow midday–8pm

Verdict: Good

grass dry — rain earlier today

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.

9°C — seeding

Soil at 6cm 17.3°C cooling to 15.0°C

Wednesday 2 September: Not worth it. No — 0.1mm of rain falling.

Wednesday 2 SeptemberConfident

No — 0.1mm of rain falling.

Poor:Grass wetness
Grass wetraining now
Poor:Ground firmness
Ground soft59mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.92
Good:Temperature
Temperature17°C
Good:Wind
Wind light19 km/h

Limiting factor:grass wetness

Thursday 3 September: Good. midday–8pm — grass dry — rain earlier today

Thursday 3 September · midday–8pmConfident

midday–8pm — grass dry — rain earlier today

Marginal:Grass wetness
Grass dryrain earlier today
Poor:Ground firmness
Ground soft72mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.98
Good:Temperature
Temperature18°C
Good:Wind
Wind light13 km/h
Sociable hours
Fine by the neighboursstarts once the dew has burnt off

Limiting factor:grass wetness

Friday 4 September: Good. No — 0.7mm of rain falling.

Friday 4 SeptemberConfident

No — 0.7mm of rain falling.

Poor:Grass wetness
Grass dryrain earlier today
Poor:Ground firmness
Ground soft67mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.90
Good:Temperature
Temperature16°C
Good:Wind
Wind light19 km/h

Limiting factor:ground firmness

Saturday 5 September: Good. 8am–5pm — ground soft — 59mm rain over the last week

Saturday 5 September · 8am–5pmConfident

8am–5pm — ground soft — 59mm rain over the last week

Good:Grass wetness
Grass dryno rain since Friday
Marginal:Ground firmness
Ground soft59mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.66
Good:Temperature
Temperature11°C
Good:Wind
Wind light2 km/h
Sociable hours
A bit early or late, but finestarts when it stops being antisocial

Limiting factor:ground firmness

Sunday 6 September: Marginal. No — 0.1mm of rain falling.

Sunday 6 SeptemberReasonably confident

No — 0.1mm of rain falling.

Poor:Grass wetness
Grass drydried off since a shower 0 hours ago
Marginal:Ground firmness
Ground soft in places46mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.93
Good:Temperature
Temperature17°C
Good:Wind
Wind light10 km/h

Limiting factor:grass wetness

Monday 7 September: Good. 11am–8pm — grass dry — rain earlier today

Monday 7 September · 11am–8pmReasonably confident

11am–8pm — grass dry — rain earlier today

Marginal:Grass wetness
Grass dryrain earlier today
Marginal:Ground firmness
Ground soft in places36mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.74
Good:Temperature
Temperature12°C
Good:Wind
Wind light7 km/h
Sociable hours
Fine by the neighboursstarts once the dew has burnt off

Limiting factor:grass wetness

Tuesday 8 September: Not worth it. No — 0.2mm of rain falling.

Tuesday 8 SeptemberReasonably confident

No — 0.2mm of rain falling.

Poor:Grass wetness
Grass wetraining now
Poor:Ground firmness
Ground soft35mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.72
Good:Temperature
Temperature14°C
Good:Wind
Wind light9 km/h

Limiting factor:grass wetness

Wednesday 9 September: Good. No — 0.8mm of rain falling.

Wednesday 9 SeptemberReasonably confident

No — 0.8mm of rain falling.

Marginal:Grass wetness
Grass dryrain earlier today
Poor:Ground firmness
Ground saturated59mm rain over the last week
Good:Growth
Growing steadilygrowth potential 0.48
Good:Temperature
Temperature12°C
Good:Wind
Wind light20 km/h

Limiting factor:ground firmness

Thursday 10 September: Good. No — ground saturated, 50mm rain over the last week.

Thursday 10 SeptemberLow confidence this far out

No — ground saturated, 50mm rain over the last week.

Good:Grass wetness
Grass dryno rain since Wednesday
Poor:Ground firmness
Ground saturated50mm rain over the last week
Good:Growth
Growing steadilygrowth potential 0.41
Good:Temperature
Temperature10°C
Good:Wind
Wind light3 km/h

Limiting factor:ground firmness

Friday 11 September: Good. 8am–8pm — ground soft — 49mm rain over the last week

Friday 11 September · 8am–8pmLow confidence this far out

8am–8pm — ground soft — 49mm rain over the last week

Good:Grass wetness
Grass dryno rain since Wednesday
Poor:Ground firmness
Ground soft49mm rain over the last week
Good:Growth
Growing wellgrowth potential 0.63
Good:Temperature
Temperature12°C
Good:Wind
Wind light16 km/h
Sociable hours
A bit early or late, but finestarts when it stops being antisocial

Limiting factor:ground firmness

Soil temperature

16.0°C61°F

at 6cm — germination depth

Cooling over the next 11 days.

Seeding conditions are open — soil is 16.0°C at 6cm and holding above 9°C.

Almost every UK and Irish lawn is a ryegrass and fescue mix, whether it was sown or turfed. We assume that, and use9°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 ryegrasslikely yours8°C5–10
Red / chewings fescuelikely yours8–10°C10–14
Tall fescue10–12°C10–14
Browntop bentColonial bentgrass10–12°C14–21
Smooth-stalked meadow grassKentucky bluegrass12–13°C14–28

What this means right now

  • Good: Seeding window open

    Seeding conditions are open — soil is 16.0°C at 6cm and holding above 9°C.

  • Worth watching: Ground still soft

    59mm rain over the last week. A mower will mark it, and a ride-on will rut it.

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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.