Hagerstown, Maryland
Best weekend slot
Monday 10am–3pm
Verdict: Good
ground soft — 104mm rain over the last week
Next mow
Sunday 3pm–8pm
Verdict: Good
ground soft — 104mm 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 — heat stress, 29°C.
Tuesday 1 SeptemberConfident
No — heat stress, 29°C.
- Good:Grass wetness
- Grass dryno rain since Thursday
- Good:Ground firmness
- Ground firm0mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.54
- Poor:Temperature
- Heat stress27°C
- Good:Wind
- Wind light14 km/h
Limiting factor:temperature
Wednesday 2 September: Good. No — 100.1mm of rain falling.
Wednesday 2 SeptemberConfident
No — 100.1mm of rain falling.
- Marginal:Grass wetness
- Grass dryno rain since Thursday
- Poor:Ground firmness
- Ground soft0mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.56
- Marginal:Temperature
- Temperature22°C
- Good:Wind
- Wind light4 km/h
Limiting factor:ground firmness
Thursday 3 September: Good. No — ground saturated, 101mm rain over the last week.
Thursday 3 SeptemberConfident
No — ground saturated, 101mm rain over the last week.
- Good:Grass wetness
- Grass dryrain earlier today
- Poor:Ground firmness
- Ground soft101mm rain over the last week
- Good:Growth
- Growing steadilygrowth potential 0.41
- Poor:Temperature
- Temperature22°C
- Good:Wind
- Wind light5 km/h
Limiting factor:ground firmness
Friday 4 September: Good. No — 0.1mm of rain falling.
Friday 4 SeptemberConfident
No — 0.1mm of rain falling.
- Marginal:Grass wetness
- Grass drydried off since a shower 3 hours ago
- Poor:Ground firmness
- Ground soft100mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.51
- Marginal:Temperature
- Temperature22°C
- Good:Wind
- Wind light4 km/h
Limiting factor:ground firmness
Saturday 5 September: Good. No — ground soft, 104mm rain over the last week.
Saturday 5 SeptemberReasonably confident
No — ground soft, 104mm rain over the last week.
- Good:Grass wetness
- Grass dryrain earlier today
- Poor:Ground firmness
- Ground soft104mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.96
- Good:Temperature
- Temperature16°C
- Good:Wind
- Wind light8 km/h
Limiting factor:ground firmness
Sunday 6 September: Good. 3pm–8pm — ground soft — 104mm rain over the last week
Sunday 6 September · 3pm–8pmReasonably confident
3pm–8pm — ground soft — 104mm rain over the last week
- Good:Grass wetness
- Grass dryno rain since Friday
- Poor:Ground firmness
- Ground soft104mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.95
- Good:Temperature
- Temperature12°C
- Good:Wind
- Wind light10 km/h
- Sociable hours
- Fine by the neighbours
Limiting factor:ground firmness
Monday 7 September: Good. 10am–3pm — ground soft — 104mm rain over the last week
Monday 7 September · 10am–3pmReasonably confident
10am–3pm — ground soft — 104mm rain over the last week
- Good:Grass wetness
- Grass dryno rain since Friday
- Marginal:Ground firmness
- Ground soft104mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.97
- Marginal:Temperature
- Temperature15°C
- Good:Wind
- Wind light1 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:ground firmness
Tuesday 8 September: Good. 8am–1pm — ground soft in places — 104mm rain over the last week
Tuesday 8 September · 8am–1pmReasonably confident
8am–1pm — ground soft in places — 104mm rain over the last week
- Good:Grass wetness
- Grass dryno rain since Friday
- Marginal:Ground firmness
- Ground soft in places104mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.86
- Marginal:Temperature
- Temperature17°C
- Good:Wind
- Wind light9 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:ground firmness
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
- Marginal:Ground firmness
- Ground soft in places104mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.96
- Good:Temperature
- Temperature20°C
- Good:Wind
- Wind light3 km/h
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 drydried off since a shower 0 hours ago
- Good:Ground firmness
- Ground soft in places5mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.69
- Poor:Temperature
- Temperature21°C
- Good:Wind
- Wind light17 km/h
Limiting factor:grass wetness
Soil temperature
80°F26.6°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 |
What this means right now
Warning: Too warm to seed
Too warm to seed — the soil is heat-stressed. Wait for it to cool.
Warning: Heat stress
Tuesday 1 September gets hot enough to stress the sward. Mow early or late, and raise the height.
Worth watching: Ground still soft
0mm rain over the last week. A mower will mark it, and a ride-on will rut it.
Forecast from Open-Meteo, refreshed hourly. Soil temperature is modelled, not measured — how that works and where the thresholds come from.