Soil temperature in Harrisburg, Pennsylvania
Soil temperature
81°F27.2°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.
| 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 Harrisburg, Pennsylvania is currently 27.2°C, and falling about 24.8°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. Too warm to seed — the soil is heat-stressed. Wait for it to cool.
6 of the next 10 days look workable. The best weekend slot right now is Monday 10am–8pm, on the basis that no rain since Friday, ground firm.
The next recommended window in Harrisburg opens at 10am on Thursday 3 September, because anything earlier is the hour your neighbours will remember. Underfoot, the ground reads as soft after 102mm 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 26.0°C cooling to 0.0°C
Tuesday 1 September: Not worth it. No — 4.3mm of rain falling.
Tuesday 1 SeptemberConfident
No — 4.3mm of rain falling.
- Good:Grass wetness
- Grass dryno rain since Thursday
- Poor:Ground firmness
- Ground soft102mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.56
- Marginal:Temperature
- Cool25°C
- Good:Wind
- Wind light14 km/h
Limiting factor:ground firmness
Wednesday 2 September: Marginal. No — 1.1mm of rain falling.
Wednesday 2 SeptemberConfident
No — 1.1mm of rain falling.
- Poor:Grass wetness
- Grass wetrain 5 hours ago
- Poor:Ground firmness
- Ground soft102mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.72
- Good:Temperature
- Temperature23°C
- Good:Wind
- Wind light8 km/h
Limiting factor:grass wetness
Thursday 3 September: Good. 10am–midday — ground soft — 108mm rain over the last week
Thursday 3 September · 10am–middayConfident
10am–midday — ground soft — 108mm rain over the last week
- Good:Grass wetness
- Grass dryrain earlier today
- Poor:Ground firmness
- Ground soft108mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.61
- Poor:Temperature
- Temperature21°C
- Good:Wind
- Wind light8 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:ground firmness
Friday 4 September: Good. 9am–11am — grass dry — dried off since a shower 5 hours ago
Friday 4 September · 9am–11amConfident
9am–11am — grass dry — dried off since a shower 5 hours ago
- Marginal:Grass wetness
- Grass drydried off since a shower 5 hours ago
- Poor:Ground firmness
- Ground soft108mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.53
- Marginal:Temperature
- Temperature22°C
- Good:Wind
- Wind light6 km/h
- Sociable hours
- A bit early or late, but finestarts once the dew has burnt off
Limiting factor:grass wetness
Saturday 5 September: Good. 11am–8pm — ground soft in places — 12mm rain over the last week
Saturday 5 September · 11am–8pmReasonably confident
11am–8pm — ground soft in places — 12mm rain over the last week
- Marginal:Grass wetness
- Grass dryrain earlier today
- Marginal:Ground firmness
- Ground soft in places12mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.99
- Good:Temperature
- Temperature15°C
- Good:Wind
- Wind light7 km/h
- Sociable hours
- Fine by the neighboursstarts once the dew has burnt off
Limiting factor:ground firmness
Sunday 6 September: Good. 10am–8pm — ground soft in places — 16mm rain over the last week
Sunday 6 September · 10am–8pmReasonably confident
10am–8pm — ground soft in places — 16mm rain over the last week
- Good:Grass wetness
- Grass dryno rain since Friday
- Marginal:Ground firmness
- Ground soft in places16mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.93
- Good:Temperature
- Temperature13°C
- Good:Wind
- Wind light6 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:ground firmness
Monday 7 September: Good. 10am–8pm — no rain since Friday, ground firm
Monday 7 September · 10am–8pmReasonably confident
10am–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 0.97
- Good:Temperature
- Temperature14°C
- Good:Wind
- Wind light2 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:none
Tuesday 8 September: Good. 8am–4pm — no rain since Friday, ground firm
Tuesday 8 September · 8am–4pmReasonably confident
8am–4pm — 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 0.95
- Marginal:Temperature
- Temperature17°C
- Good:Wind
- Wind light4 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.
- Good:Grass wetness
- Grass dryno rain since Friday
- Good:Ground firmness
- Ground firm16mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.96
- Good:Temperature
- Temperature19°C
- Good:Wind
- Wind light5 km/h
Limiting factor:none
Thursday 10 September: Not worth it. No — ground frozen.
Thursday 10 SeptemberLow confidence this far out
No — ground frozen.
- Good:Grass wetness
- Grass drydried off since a shower 0 hours ago
- Good:Ground firmness
- Ground firm10mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.78
- Marginal:Temperature
- Temperature21°C
- Good:Wind
- Wind light8 km/h
Limiting factor:none
Nearby
Your own postcode
These are town-centre figures. Yours will differ a little.