TR21, Cornwall
Mowing
When you can next cut it, and the best slot this weekend.
Best weekend slot
Sunday midday–6pm
Verdict: Pushing it, 35% chance it holds
grass dry — dry again 5 hours after a shower
Next mow
Tomorrow 8am–5pm
Verdict: Touch and go, 45% chance it holds
rain earlier that day, ground firm
The next 10 days
Each row is a day, morning on the left. The more solid a block, the more of the forecast runs agree you can mow. Open a day for the hour-by-hour forecast behind it.
Monday 19 October: no hours worth using. No — 0.8mm of rain falling.
Monday 19 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — 25% <5% 10% 10% <5% <5% <5% <5% <5% <5% — — Verdict Already gone Already gone Already gone Already gone Pushing it Forget it Forget it Forget it Forget it Forget it Forget it Forget it Forget it Forget it dark dark Rainchance · · · · 57% 67% 70% 68% 60% 62% 54% 49% 37% 44% 41% 29% Rainmm · · · · 0.5 0.5 0.6 0.6 0.4 0.4 0.4 0.4 0.2 0.3 0.2 0.1 Grass · · · · damp soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked Ground · · · · firm firm firm firm firm firm firm firm firm firm firm firm Temp · · · · 11° 12° 12° 12° 11° 11° 11° 12° 12° 12° 12° 13° Windkm/h · · · · 26 24 26 14 8 5 5 10 14 15 16 18 Daylight · · · · ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — Growth: growing slowly (growth potential 0.24). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Monday 19 OctoberConfident
No — 0.8mm of rain falling.
25% pushing it. About 2 runs in 3 found the grass too wet.
Limiting factor:grass wetness
Tuesday 20 October: 9 hours worth using. 8am–5pm — rain earlier that day, ground firm
Tuesday 20 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 65% 75% 80% 85% 90% 85% 75% 75% 70% 45% 40% — — Verdict dark dark dark Good to go Good to go Good to go Good to go Prime time Good to go Good to go Good to go Good to go Touch and go Touch and go dark dark Rainchance 13% 12% 9% 25% 11% 10% 16% 9% 15% 23% 23% 29% 51% 48% 67% 66% Rainmm 0.1 — — 0.1 — — 0.1 — 0.1 0.1 0.1 0.1 0.4 0.5 0.7 1.1 Grass damp damp damp damp damp dry dry dry dry dry dry damp damp wet wet soaked Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 13° 13° 14° 14° 14° 14° 14° 14° 14° 14° 14° 13° 13° 13° 14° 14° Windkm/h 9 13 16 17 21 22 24 21 23 25 27 38 30 30 33 36 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — Growth: growing slowly (growth potential 0.33). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Tuesday 20 October · 8am–5pmLow confidence this far out
8am–5pm — rain earlier that day, ground firm
45% touch and go — the chance it holds right through, not the chance at any one hour. About half the runs hit rain.
Limiting factor:none
Wednesday 21 October: no hours worth using. No — 0.1mm of rain falling.
Wednesday 21 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 50% 50% 60% 45% 50% 55% 50% 55% 55% 50% 45% — — Verdict dark dark dark Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go dark dark Rainchance 44% 42% 52% 48% 44% 31% 50% 49% 44% 45% 44% 42% 50% 52% 55% 59% Rainmm 0.2 0.2 0.3 0.3 0.2 0.2 0.2 0.3 0.2 0.2 0.2 0.2 0.2 0.4 0.2 0.5 Grass damp damp damp damp damp damp dry dry dry dry dry dry dry damp damp damp Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 12° 12° 13° 12° 12° 12° 13° 13° 13° 13° 13° 13° 13° 13° 13° 13° Windkm/h 59 58 54 55 56 55 54 52 49 47 44 42 41 41 41 43 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — Growth: growing slowly (growth potential 0.29). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Wednesday 21 OctoberLow confidence this far out
No — 0.1mm of rain falling.
60% touch and go. About 1 run in 3 found the grass too wet.
Limiting factor:grass wetness
Thursday 22 October: no hours worth using. No — 0.1mm of rain falling.
Thursday 22 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 45% 45% 40% 35% 30% 25% 20% 15% <5% <5% <5% — — Verdict dark dark dark Touch and go Touch and go Touch and go Pushing it Pushing it Pushing it Pushing it Forget it Forget it Forget it Forget it dark dark Rainchance 43% 41% 49% 50% 47% 43% 58% 54% 59% 67% 65% 70% 62% 72% 62% 56% Rainmm 0.2 0.2 0.2 0.2 0.2 0.3 0.4 0.4 0.5 1.0 1 1.5 1.1 1.3 1.0 1.1 Grass damp damp damp damp damp damp damp damp wet soaked soaked soaked soaked soaked soaked soaked Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 14° 14° 14° 14° 14° 14° 14° 14° 13° 13° 13° 14° 14° 15° 15° 15° Windkm/h 36 31 27 23 19 18 21 25 30 33 37 42 54 68 77 75 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — Growth: growing steadily (growth potential 0.36). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Thursday 22 OctoberLow confidence this far out
No — 0.1mm of rain falling.
45% touch and go. About half the runs found the grass too wet.
Limiting factor:grass wetness
Friday 23 October: no hours worth using. No — 0.2mm of rain falling.
Friday 23 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 25% 30% 35% 30% 45% 55% 55% 35% 40% 55% 60% — — Verdict dark dark dark Pushing it Pushing it Pushing it Pushing it Touch and go Touch and go Touch and go Pushing it Touch and go Touch and go Touch and go dark dark Rainchance 61% 55% 60% 52% 52% 52% 57% 42% 31% 31% 51% 47% 38% 33% 45% 38% Rainmm 0.5 0.3 0.5 0.3 0.4 0.3 0.3 0.3 0.1 0.2 0.4 0.3 0.2 0.2 0.3 0.2 Grass wet wet wet damp damp damp damp damp damp damp damp damp dry dry damp dry Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 12° 12° 13° 12° 12° 12° 11° 11° 11° 11° 11° 11° 11° 11° 12° 12° Windkm/h 82 80 77 73 68 63 61 59 59 60 62 62 60 58 56 57 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — Growth: growing slowly (growth potential 0.21). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Friday 23 OctoberLow confidence this far out
No — 0.2mm of rain falling.
60% touch and go. About 1 run in 3 found the grass too wet.
Limiting factor:grass wetness
Saturday 24 October: no hours worth using. No — 1.3mm of rain falling.
Saturday 24 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — 55% 45% 40% 45% 30% 25% 30% 20% 25% 20% — — Verdict dark dark dark dark Touch and go Touch and go Touch and go Touch and go Pushing it Pushing it Pushing it Pushing it Pushing it Pushing it dark dark Rainchance 27% 28% 25% 23% 39% 24% 29% 18% 33% 31% 22% 27% 29% 24% 25% 24% Rainmm 0.3 0.3 0.2 0.4 1.2 0.4 1 0.5 1.2 1.2 0.8 0.7 0.7 0.5 0.5 0.2 Grass dry dry dry damp damp damp wet wet wet wet wet soaked soaked soaked soaked soaked Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 13° 13° 13° 13° 13° 12° 12° 13° 13° 14° 15° 15° 16° 16° 16° 16° Windkm/h 38 35 33 32 31 32 36 40 45 50 55 58 57 53 49 46 Daylight — — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — Growth: growing steadily (growth potential 0.35). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Saturday 24 OctoberLow confidence this far out
No — 1.3mm of rain falling.
55% touch and go. About half the runs were too windy.
Limiting factor:wind
Sunday 25 October: 6 hours worth using. midday–6pm — grass dry — dry again 5 hours after a shower
Sunday 25 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 15% 35% 50% 60% 75% 75% 75% 70% 80% 75% — — — Verdict dark dark dark Forget it Pushing it Touch and go Touch and go Good to go Good to go Good to go Good to go Good to go Good to go dark dark dark Rainchance 29% 29% 20% 22% 16% 24% 22% 12% 16% 18% 25% 20% 22% 18% 10% 22% Rainmm 0.3 0.3 0.2 0.2 0.1 0.2 0.2 0.1 0.1 0.1 0.2 0.2 0.2 0.1 0.2 0.3 Grass soaked soaked soaked soaked wet wet damp damp damp dry dry dry dry dry dry dry Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 16° 16° 16° 16° 16° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 14° Windkm/h 51 53 56 59 62 65 67 68 68 67 64 62 60 58 56 54 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: growing steadily (growth potential 0.43). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Sunday 25 October · midday–6pmLow confidence this far out
midday–6pm — grass dry — dry again 5 hours after a shower
35% pushing it — the chance it holds right through, not the chance at any one hour. About 2 runs in 3 hit rain.
Limiting factor:grass wetness
Monday 26 October: no hours worth using. No — 0.1mm of rain falling.
Monday 26 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 45% 40% 45% 45% 50% 45% 45% 45% 45% 40% — — — Verdict dark dark dark Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go Touch and go dark dark dark Rainchance 16% 20% 25% 16% 12% 18% 20% 16% 24% 14% 16% 22% 22% 10% 31% 22% Rainmm 0.1 0.2 0.5 0.2 0.1 0.2 0.3 0.3 0.2 0.2 0.2 0.2 0.3 0.2 0.3 0.3 Grass damp damp wet wet wet wet damp damp wet wet wet wet wet wet wet soaked Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° Windkm/h 35 39 40 38 34 29 24 19 14 12 15 22 29 34 38 40 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: growing steadily (growth potential 0.41). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Monday 26 OctoberLow confidence this far out
No — 0.1mm of rain falling.
50% touch and go. About half the runs went against it.
Limiting factor:none
Tuesday 27 October: 7 hours worth using. 11am–6pm — windy — 42 km/h
Tuesday 27 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 50% 55% 65% 75% 70% 70% 70% 75% 65% 80% — — — Verdict dark dark dark Touch and go Touch and go Touch and go Good to go Good to go Good to go Good to go Good to go Good to go Good to go dark dark dark Rainchance 22% 18% 18% 20% 14% 20% 12% 20% 14% 22% 14% 25% 14% 10% 12% 12% Rainmm 0.2 0.2 0.1 0.2 0.2 0.1 0.2 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.1 Grass wet wet damp damp damp damp damp damp dry dry dry dry dry dry dry dry Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 15° 15° 15° 15° 15° 15° 15° 14° 14° 14° 14° 14° 14° 14° 14° 14° Windkm/h 53 53 52 51 50 48 47 45 44 44 43 42 42 41 41 40 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: growing steadily (growth potential 0.39). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Tuesday 27 October · 11am–6pmLow confidence this far out
11am–6pm — windy — 42 km/h
35% pushing it — the chance it holds right through, not the chance at any one hour. About 2 runs in 3 hit rain.
Limiting factor:wind
Wednesday 28 October: 10 hours worth using. 8am–6pm — windy — 43 km/h
Wednesday 28 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — 85% 80% 90% 80% 90% 90% 90% 85% 90% 90% — — — Verdict dark dark dark Good to go Good to go Prime time Good to go Prime time Prime time Prime time Good to go Prime time Prime time dark dark dark Rainchance 24% 12% 10% 10% 18% 8% 22% 8% 10% 4% 16% 10% 6% 14% 14% 8% Rainmm 0.1 0.1 — — 0.1 — 0.1 — 0.1 — 0.1 0.1 — 0.1 0.1 0.2 Grass dry dry dry dry dry dry dry dry dry dry dry dry dry dry dry dry Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 14° 14° 14° 14° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° 15° Windkm/h 41 42 43 43 43 44 44 44 44 44 45 45 45 45 45 45 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: growing steadily (growth potential 0.38). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.Chance is the share of 94 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.
Wednesday 28 October · 8am–6pmLow confidence this far out
8am–6pm — windy — 43 km/h
50% touch and go — the chance it holds right through, not the chance at any one hour. About half the runs hit rain.
Limiting factor:wind
good to go touch and go dark, frost or snow already goneFainter means fewer forecast runs agree.
Growth
How fast it is growing, and when it will need cutting again.
24%Growing slowly
Of the fastest this grass could grow. The turf-industry measure, from today's temperature and day length.
Growing slowly — roughly 0.9mm a day. It will not put on enough to need cutting within the next 10 days.
Held back by both temperature and short days — 10.6 hours of daylight at 12°C.
- Over the next 10 days
- about 12mm of leaf
- Next cut due
- not within the next ten days
This only knows temperature and day length. Feeding, watering, shade and cutting height all move it, so treat it as a rough guide.
Worked out from the PACE Turf growth potential model and day length —how and why.
Seeding
Soil temperature at germination depth, and when the window opens.
Soil temperature in TR21, Cornwall
15.3°C60°F
at 6cm — germination depth
Seeding conditions are open — soil is 15.3°C at 6cm and holding above 9°C.
Cooling over the next 10 days.
An independent estimate from air temperature gives 13.1°C, 2.2°C away. Treat the figure as approximate.
Almost every UK and Irish lawn is a ryegrass and fescue mix, whether it was sown or turfed. We assume that, and use 9°C as the seeding threshold.
Thresholds for every species
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 needed | Days to sprout |
|---|---|---|
| Perennial ryegrasslikely yours | 8°C | 5–10 |
| Red / chewings fescuelikely yours | 8–10°C | 10–14 |
| Tall fescue | 10–12°C | 10–14 |
| Browntop bentColonial bentgrass | 10–12°C | 14–21 |
| Smooth-stalked meadow grassKentucky bluegrass | 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 not growing fast enough to make much use of 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.
TR21, Cornwall in detail
Soil temperature in TR21, Cornwall is currently 15.3°C at 6cm, and falling about 0.6°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 perennial ryegrass with fescue, which is what most lawns round here are sown with. That blend needs the soil to hold above 9°C before seed germinates reliably. Seeding conditions are open — soil is 15.3°C at 6cm and holding above 9°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 midday–6pm, on the basis that grass dry — dry again 5 hours after a shower.
The next recommended window in TR21 opens at 8am on Tuesday 20 October, because that is first light. Underfoot, the ground reads as firm after 6mm rain over the last week, soil texture assumed.
Save this lawn and we will email you when the windows open.
We already send you the forecast email? Use the same address.
Chances counted across 94 forecast runs from MOGREPS-UK, 2km and ICON-EU-EPS, 7km and ECMWF IFS ensemble, 25km. Forecast from Open-Meteo, refreshed through the day. Soil temperature is modelled, not measured — how that works and where the thresholds come from.