Soil temperature in Rockford, Illinois
Soil temperature
83°F28.1°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 Rockford, Illinois is currently 28.1°C, and falling about 25.9°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.
7 of the next 10 days are good mowing days. The best weekend slot right now is Sunday 10am–11am, on the basis that no rain since Saturday, ground firm.
The next recommended window in Rockford opens at 8am on Wednesday 2 September, because anything earlier is the hour your neighbours will remember. Underfoot, the ground reads as firm after 2mm 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 26.8°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 Sunday
- Good:Ground firmness
- Ground firm2mm rain over the last week
- Good:Growth
- Growing steadilygrowth potential 0.50
- Poor:Temperature
- Heat stress26°C
- Good:Wind
- Wind light8 km/h
Limiting factor:temperature
Wednesday 2 September: Good. 8am–11am — growing slowly — growth potential 0.31
Wednesday 2 September · 8am–11amConfident
8am–11am — growing slowly — growth potential 0.31
- Good:Grass wetness
- Grass dryno rain since Sunday
- Good:Ground firmness
- Ground firm2mm rain over the last week
- Marginal:Growth
- Growing slowlygrowth potential 0.31
- Poor:Temperature
- Temperature23°C
- Good:Wind
- Wind light6 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:growth
Thursday 3 September: Good. 4pm–5pm — heat stress — 27°C
Thursday 3 September · 4pm–5pmConfident
4pm–5pm — heat stress — 27°C
- Good:Grass wetness
- Grass dryno rain since Sunday
- Good:Ground firmness
- Ground firm2mm rain over the last week
- Good:Growth
- Growing steadilygrowth potential 0.47
- Marginal:Temperature
- Temperature23°C
- Good:Wind
- Wind light7 km/h
- Sociable hours
- Fine by the neighboursstarts once the rain has passed
Limiting factor:temperature
Friday 4 September: Good. 10am–11am — heat stress — 27°C
Friday 4 September · 10am–11amConfident
10am–11am — heat stress — 27°C
- Good:Grass wetness
- Grass drydried off since a shower 2 hours ago
- Good:Ground firmness
- Ground firm2mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.57
- Poor:Temperature
- Temperature21°C
- Good:Wind
- Wind light8 km/h
- Sociable hours
- Fine by the neighboursstarts once the dew has burnt off
Limiting factor:temperature
Saturday 5 September: Good. 6pm–8pm — cool — 25°C
Saturday 5 September · 6pm–8pmReasonably confident
6pm–8pm — cool — 25°C
- Marginal:Grass wetness
- Grass drydried off since a shower 5 hours ago
- Good:Ground firmness
- Ground firm4mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.75
- Marginal:Temperature
- Temperature21°C
- Good:Wind
- Wind light19 km/h
- Sociable hours
- A bit early or late, but finestarts when it stops being antisocial
Limiting factor:temperature
Sunday 6 September: Good. 10am–11am — no rain since Saturday, ground firm
Sunday 6 September · 10am–11amReasonably confident
10am–11am — no rain since Saturday, ground firm
- Marginal:Grass wetness
- Grass dryrain earlier today
- Good:Ground firmness
- Ground firm9mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.96
- Good:Temperature
- Temperature18°C
- Good:Wind
- Wind light10 km/h
- Sociable hours
- Fine by the neighboursstarts when it stops being antisocial
Limiting factor:none
Monday 7 September: Good. No — 0.7mm of rain falling.
Monday 7 SeptemberReasonably confident
No — 0.7mm of rain falling.
- Poor:Grass wetness
- Grass wetraining now
- Good:Ground firmness
- Ground firm11mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.97
- Good:Temperature
- Temperature17°C
- Good:Wind
- Wind light10 km/h
Limiting factor:grass wetness
Tuesday 8 September: Good. 5pm–8pm — ground firm — 15mm rain over the last week
Tuesday 8 September · 5pm–8pmReasonably confident
5pm–8pm — ground firm — 15mm rain over the last week
- Poor:Grass wetness
- Grass drydried off since a shower 0 hours ago
- Good:Ground firmness
- Ground firm15mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.96
- Good:Temperature
- Temperature19°C
- Good:Wind
- Wind light10 km/h
- Sociable hours
- A bit early or late, but finestarts once the rain has passed
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 dryrain earlier today
- Good:Ground firmness
- Ground firm16mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.86
- Marginal:Temperature
- Temperature20°C
- Good:Wind
- Wind light13 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 dryno rain since Tuesday
- Good:Ground firmness
- Ground firm16mm rain over the last week
- Good:Growth
- Growing wellgrowth potential 0.92
- Good:Temperature
- Temperature13°C
- Good:Wind
- Wind light21 km/h
Limiting factor:none
Nearby
Your own postcode
These are town-centre figures. Yours will differ a little.