Portsmouth, England
Best weekend slot
Saturday 8am–8pm
Verdict: Good
rain earlier today, ground firm
Next mow
Today 11am–8pm
Verdict: Good
dried off since a shower 1 hour ago, ground firm
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 18.6°C cooling to 16.9°C
Wednesday 2 September: Good. 11am–8pm — dried off since a shower 1 hour ago, ground firm
Wednesday 2 September · 11am–8pmConfident
11am–8pm — dried off since a shower 1 hour ago, ground firm
- Good:Grass wetness
- Grass drydried off since a shower 1 hour ago
- Good:Ground firmness
- Ground firm20mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.98
- Good:Temperature
- Temperature17°C
- Good:Wind
- Wind light11 km/h
- Sociable hours
- Fine by the neighboursstarts once the rain has passed
Limiting factor:none
Thursday 3 September: Good. 8am–8pm — rain earlier today, ground firm
Thursday 3 September · 8am–8pmConfident
8am–8pm — rain earlier today, ground firm
- Good:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm20mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 1.00
- Good:Temperature
- Temperature19°C
- Good:Wind
- Wind light19 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:none
Friday 4 September: Good. 11am–2pm — dried off since a shower 1 hour ago, ground firm
Friday 4 September · 11am–2pmConfident
11am–2pm — dried off since a shower 1 hour ago, ground firm
- Good:Grass wetness
- Grass drydried off since a shower 0 hours ago
- Good:Ground firmness
- Ground firm18mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 1.00
- Good:Temperature
- Temperature19°C
- Good:Wind
- Wind light21 km/h
- Sociable hours
- Fine by the neighboursstarts once the rain has passed
Limiting factor:none
Saturday 5 September: Good. 8am–8pm — rain earlier today, ground firm
Saturday 5 September · 8am–8pmConfident
8am–8pm — rain earlier today, ground firm
- Good:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm19mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.95
- Good:Temperature
- Temperature15°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–8pm — no rain since Friday, ground firm
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 firm10mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 1.00
- Good:Temperature
- Temperature19°C
- Good:Wind
- Wind light12 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:none
Monday 7 September: Good. 8am–8pm — no rain since Friday, ground firm
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 firm9mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.95
- Good:Temperature
- Temperature15°C
- Good:Wind
- Wind light12 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:none
Tuesday 8 September: Marginal. No — 0.2mm of rain falling.
Tuesday 8 SeptemberReasonably confident
No — 0.2mm of rain falling.
- Good:Grass wetness
- Grass dryno rain since Friday
- Good:Ground firmness
- Ground firm2mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.83
- Good:Temperature
- Temperature16°C
- Good:Wind
- Wind light14 km/h
Limiting factor:none
Wednesday 9 September: Good. 8am–8pm — wind light — 20 km/h
Wednesday 9 September · 8am–8pmReasonably confident
8am–8pm — wind light — 20 km/h
- Good:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm8mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.69
- Good:Temperature
- Temperature14°C
- Marginal:Wind
- Wind light20 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:wind
Thursday 10 September: Good. 8am–8pm — no rain since Wednesday, ground firm
Thursday 10 September · 8am–8pmLow confidence this far out
8am–8pm — no rain since Wednesday, ground firm
- Good:Grass wetness
- Grass dryno rain since Wednesday
- Good:Ground firmness
- Ground firm8mm rain over the last week
- Good:Growth
- Growing steadilygrowth potential 0.42
- Good:Temperature
- Temperature10°C
- Good:Wind
- Wind light7 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:none
Friday 11 September: Good. 8am–8pm — no rain since Wednesday, ground firm
Friday 11 September · 8am–8pmLow confidence this far out
8am–8pm — no rain since Wednesday, ground firm
- Good:Grass wetness
- Grass dryno rain since Wednesday
- Good:Ground firmness
- Ground firm8mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.64
- Good:Temperature
- Temperature11°C
- Good:Wind
- Wind light13 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:none
Soil temperature
17.2°C63°F
at 6cm — germination depth
Cooling over the next 11 days.
Seeding conditions are open — soil is 17.2°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.
| Species | Soil temp | Days |
|---|---|---|
| Perennial ryegrasslikely yours | 8°C | 5–10 |
| Red / chewings fescuelikely yours | 8–10°C | 10–14 |
| Tall fescue | 10–12°C | 10–14 |
| Browntop bentColonial bentgrass | 10–12°C | 14–21 |
| Smooth-stalked meadow grassKentucky bluegrass | 12–13°C | 14–28 |
What this means right now
Good: Seeding window open
Seeding conditions are open — soil is 17.2°C at 6cm and holding above 9°C.
Forecast from Open-Meteo, refreshed hourly. Soil temperature is modelled, not measured — how that works and where the thresholds come from.