State College, Pennsylvania
Mowing
When you can next cut it, and the best slot this weekend.
Best weekend slot
Monday 10am–8pm
Verdict: Good
ground soft in places — 77mm rain over the last week
Next mow
Friday 11am–5pm
Verdict: Good
grass dry — rain earlier today
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 23.1°C cooling to 0.0°C
Wednesday 2 September: Not worth it. No — cool, 24°C.
Wednesday 2 SeptemberConfident
No — cool, 24°C.
- Good:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm1mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.80
- Good:Temperature
- Temperature23°C
- Good:Wind
- Wind light1 km/h
Limiting factor:temperature
Thursday 3 September: Good. No — 1.1mm of rain falling.
Thursday 3 SeptemberConfident
No — 1.1mm of rain falling.
- Marginal:Grass wetness
- Grass drydried off since a shower 4 hours ago
- Poor:Ground firmness
- Ground soft21mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.70
- Marginal:Temperature
- Temperature21°C
- Good:Wind
- Wind light13 km/h
Limiting factor:ground firmness
Friday 4 September: Good. 11am–5pm — grass dry — rain earlier today
Friday 4 September · 11am–5pmConfident
11am–5pm — grass dry — rain earlier today
- Marginal:Grass wetness
- Grass dryrain earlier today
- Poor:Ground firmness
- Ground soft70mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.88
- Good:Temperature
- Temperature20°C
- Good:Wind
- Wind light5 km/h
- Sociable hours
- Fine by the neighboursstarts once the dew has burnt off
Limiting factor:grass wetness
Saturday 5 September: Good. midday–8pm — ground soft — 77mm rain over the last week
Saturday 5 September · midday–8pmConfident
midday–8pm — ground soft — 77mm rain over the last week
- Marginal:Grass wetness
- Grass dryrain earlier today
- Poor:Ground firmness
- Ground soft77mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.99
- Good:Temperature
- Temperature16°C
- Good:Wind
- Wind light3 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 — 77mm rain over the last week
Sunday 6 September · 10am–8pmReasonably confident
10am–8pm — ground soft — 77mm rain over the last week
- Good:Grass wetness
- Grass dryno rain since Friday
- Marginal:Ground firmness
- Ground soft77mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.81
- Good:Temperature
- Temperature11°C
- Good:Wind
- Wind light5 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:ground firmness
Monday 7 September: Good. 10am–8pm — ground soft in places — 77mm rain over the last week
Monday 7 September · 10am–8pmReasonably confident
10am–8pm — ground soft in places — 77mm rain over the last week
- Good:Grass wetness
- Grass dryno rain since Friday
- Marginal:Ground firmness
- Ground soft in places77mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.75
- Good:Temperature
- Temperature10°C
- Good:Wind
- Wind light4 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:ground firmness
Tuesday 8 September: Good. 8am–8pm — ground soft in places — 76mm rain over the last week
Tuesday 8 September · 8am–8pmReasonably confident
8am–8pm — ground soft in places — 76mm rain over the last week
- Good:Grass wetness
- Grass dryno rain since Friday
- Good:Ground firmness
- Ground soft in places76mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.83
- Good:Temperature
- Temperature13°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
Wednesday 9 September: Good. 8am–midday — no rain since Friday, ground firm
Wednesday 9 September · 8am–middayReasonably confident
8am–midday — no rain since Friday, ground firm
- Good:Grass wetness
- Grass dryno rain since Friday
- Good:Ground firmness
- Ground firm76mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.83
- Marginal:Temperature
- Temperature18°C
- Good:Wind
- Wind light5 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:ground firmness
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 Friday
- Good:Ground firmness
- Ground firm56mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.71
- Good:Temperature
- Temperature22°C
- Good:Wind
- Wind light17 km/h
Limiting factor:none
Friday 11 September: Not worth it. No — ground frozen.
Friday 11 SeptemberLow confidence this far out
No — ground frozen.
- Good:Grass wetness
- Grass dryno rain since Friday
- Good:Ground firmness
- Ground firm7mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.82
- Good:Temperature
- Temperature12°C
- Good:Wind
- Wind light2 km/h
Limiting factor:none
Growth
How fast it is growing, and when it will need cutting again.
0.80Growing strongly
Growth potential, 0 to 1 — the turf-industry measure of how fast grass can grow at today's temperature and day length.
Putting on about 4.8mm a day. A lawn cut today would be ready for another in around 4 days.
Worked out from the PACE Turf growth potential model and day length —how and why.
What this means right now
Good: Seeding window open
Seeding conditions are open — soil is 23.5°C at 6cm and holding above 12.5°C.
Warning: Heat stress
Thursday 3 September gets hot enough to stress the sward. Mow early or late, and raise the height.
Worth watching: Ground still soft
21mm rain over the last week. A mower will mark it, and a ride-on will rut it.
Seeding
Soil temperature at germination depth, and when the window opens.
Soil temperature
74°F23.5°C
at 6cm — germination depth
Cooling over the next 10 days.
Seeding conditions are open — soil is 23.5°C at 6cm and holding above 12.5°C.
Cross-checks against an independent estimate from air temperature (22.8°C), which agrees to within 0.3°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 |
Feeding
Why timing decides whether a feed does anything at all.
Coming in the app
Grass takes up nitrogen when it is growing. Feed a lawn that has stopped and most of it washes past the roots — which is why timing beats product choice.
Right now this lawn is growing well enough to use a feed.
The app will work out the actual feeding windows for your lawn — along with weed control, scarifying and moss treatment — and tell you when they open without you having to check.
State College, Pennsylvania in detail
Soil temperature at 6cm in State College, Pennsylvania is currently 23.5°C, and falling about 23.2°C over the next 10 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 23.5°C at 6cm and holding above 12.5°C.
7 of the next 10 days are good mowing days. The best weekend slot right now is Monday 10am–8pm, on the basis that ground soft in places — 77mm rain over the last week.
The next recommended window in State College opens at 11am on Friday 4 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 1mm rain over the last week.
Forecast from Open-Meteo, refreshed hourly. Soil temperature is modelled, not measured — how that works and where the thresholds come from.