Soil temperature in New Haven, Connecticut
Soil temperature
69°F20.6°C
at 6cm — germination depth
Cooling over the next 11 days.
Seeding conditions are open — soil is 20.6°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.
| 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 New Haven, Connecticut is currently 20.6°C, and falling about 21.8°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 20.6°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 rain earlier today, ground firm.
The next recommended window in New Haven opens at midday 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 0mm rain over the last week.
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 20.2°C cooling to 0.0°C
Tuesday 1 September: Not worth it. No — grass wet, rain earlier today.
Tuesday 1 SeptemberConfident
No — grass wet, rain earlier today.
- Poor:Grass wetness
- Grass wetrain earlier today
- Good:Ground firmness
- Ground firm0mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.99
- Good:Temperature
- Temperature18°C
- Good:Wind
- Wind light10 km/h
Limiting factor:grass wetness
Wednesday 2 September: Good. midday–8pm — grass dry — no rain since Tuesday
Wednesday 2 September · midday–8pmConfident
midday–8pm — grass dry — no rain since Tuesday
- Marginal:Grass wetness
- Grass dryno rain since Tuesday
- Good:Ground firmness
- Ground firm5mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.98
- Good:Temperature
- Temperature17°C
- Good:Wind
- Wind light10 km/h
- Sociable hours
- Fine by the neighboursstarts once the dew has burnt off
Limiting factor:grass wetness
Thursday 3 September: Good. 1pm–5pm — cool — 25°C
Thursday 3 September · 1pm–5pmConfident
1pm–5pm — cool — 25°C
- Poor:Grass wetness
- Grass drydried off since a shower 5 hours ago
- Good:Ground firmness
- Ground firm5mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.92
- Marginal:Temperature
- Temperature21°C
- Good:Wind
- Wind light20 km/h
- Sociable hours
- Fine by the neighboursstarts once the dew has burnt off
Limiting factor:temperature
Friday 4 September: Good. 8am–8pm — rain earlier today, ground firm
Friday 4 September · 8am–8pmConfident
8am–8pm — rain earlier today, ground firm
- Good:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm25mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.82
- Marginal:Temperature
- Temperature20°C
- Good:Wind
- Wind light5 km/h
- Sociable hours
- A bit early or late, but finestarts once the dew has burnt off
Limiting factor:temperature
Saturday 5 September: Good. 8am–7pm — no rain since Thursday, ground firm
Saturday 5 September · 8am–7pmReasonably confident
8am–7pm — no rain since Thursday, ground firm
- Good:Grass wetness
- Grass dryno rain since Thursday
- Good:Ground firmness
- Ground firm25mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.96
- Good:Temperature
- Temperature17°C
- Good:Wind
- Wind light19 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 — rain earlier today, ground firm
Sunday 6 September · 10am–8pmReasonably confident
10am–8pm — rain earlier today, ground firm
- Good:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm25mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.95
- Good:Temperature
- Temperature14°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. 10am–8pm — no rain since Saturday, ground firm
Monday 7 September · 10am–8pmReasonably confident
10am–8pm — no rain since Saturday, ground firm
- Good:Grass wetness
- Grass dryno rain since Saturday
- Good:Ground firmness
- Ground firm25mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.96
- Good:Temperature
- Temperature15°C
- Good:Wind
- Wind light10 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:none
Tuesday 8 September: Good. 8am–8pm — no rain since Saturday, ground firm
Tuesday 8 September · 8am–8pmReasonably confident
8am–8pm — no rain since Saturday, ground firm
- Good:Grass wetness
- Grass dryno rain since Saturday
- Good:Ground firmness
- Ground firm25mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.92
- Good:Temperature
- Temperature19°C
- Good:Wind
- Wind light13 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:none
Wednesday 9 September: Not worth it. No — ground frozen.
Wednesday 9 SeptemberLow confidence this far out
No — ground frozen.
- Marginal:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm20mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.95
- Good:Temperature
- Temperature16°C
- Good:Wind
- Wind light13 km/h
Limiting factor:grass wetness
Thursday 10 September: Not worth it. No — ground frozen.
Thursday 10 SeptemberLow confidence this far out
No — ground frozen.
- Poor:Grass wetness
- Grass slightly dampraining now
- Poor:Ground firmness
- Ground soft23mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.95
- Good:Temperature
- Temperature21°C
- Good:Wind
- Wind light17 km/h
Limiting factor:ground firmness
Nearby
Your own postcode
These are town-centre figures. Yours will differ a little.