Salt Lake City, Utah
Mowing
When you can next cut it, and the best slot this weekend.
Current conditions · 4am, this hour
Not now — it’s dark
- Grass
- dry
- Ground
- firm
- Rain
- 15% chance
- Temp
- 14°
- Wind
- 10 km/h
Forecast for this hour, not a measurement.
Best weekend slot
Sunday 8am–7pm
Verdict: Prime time, >95% chance at its best hour
ground firm — 27mm rain over the last week, very fine (heavy clay) soil
Next mow
Today 8am–7pm
Verdict: Prime time, >95% chance at its best hour
dry since Wednesday by then, 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.
Tuesday 20 October: 11 hours worth using. 8am–7pm — dry since Wednesday by then, 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 — — — 80% 70% 85% 90% 90% 95% >95% >95% >95% >95% >95% — — Verdict dark dark dark Good to go Good to go Prime time Prime time Prime time Prime time Prime time Prime time Prime time Prime time Prime time dark dark Rainchance 12% 8% 10% 4% 11% 1% 8% 8% 6% 2% 3% 0% 1% 2% 0% 0% Rainmm 0.2 0.1 — 0.1 0.1 — — — — — — — — — — — Grass damp damp damp damp damp 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° 13° 13° 14° 16° 18° 20° 22° 22° 23° 23° 23° 22° 18° 16° Windkm/h 6 8 9 10 9 8 8 7 12 13 11 11 10 6 8 4 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — Growth: growing well (growth potential 0.62). 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.
Tuesday 20 October · 8am–7pmReasonably confident
8am–7pm — dry since Wednesday by then, ground firm
>95% prime time at its best hour, 65% that all 11 hours stay mowable. Every forecast run agrees.
Limiting factor:none
Wednesday 21 October: 11 hours worth using. 8am–7pm — dry for over a week by then, ground firm
Loading the hour-by-hour forecast…
Growth: growing well (growth potential 0.56). 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.
Wednesday 21 October · 8am–7pmConfident
8am–7pm — dry for over a week by then, ground firm
>95% prime time at its best hour, 75% that all 11 hours stay mowable. Every forecast run agrees.
Limiting factor:none
Thursday 22 October: 10 hours worth using. 8am–5pm — rain earlier that day, ground firm
Loading the hour-by-hour forecast…
Growth: growing well (growth potential 0.66). 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.
Thursday 22 October · best slot8am–5pmReasonably confident
8am–5pm — rain earlier that day, ground firm
>95% prime time at its best hour, 50% that all 9 hours stay mowable. Every forecast run agrees.
Also mowable today: 6pm–7pm (70%) — each at its best hour
Limiting factor:none
Friday 23 October: no hours worth using. No — 0.1mm of rain falling.
Loading the hour-by-hour forecast…
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.
Friday 23 OctoberReasonably confident
No — 0.1mm of rain falling.
35% pushing it at its best hour. About 2 runs in 3 found the grass too wet.
Limiting factor:grass wetness
Saturday 24 October: 5 hours worth using. 2pm–7pm — grass dry — rain earlier that day
Loading the hour-by-hour forecast…
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.
Saturday 24 October · 2pm–7pmReasonably confident
2pm–7pm — grass dry — rain earlier that day
85% prime time at its best hour, 70% that all 5 hours stay mowable. About 1 run in 6 found the ground too soft.
Limiting factor:grass wetness
Sunday 25 October: 11 hours worth using. 8am–7pm — ground firm — 27mm rain over the last week, very fine (heavy clay) soil
Loading the hour-by-hour forecast…
Growth: growing slowly (growth potential 0.30). 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.
Sunday 25 October · 8am–7pmReasonably confident
8am–7pm — ground firm — 27mm rain over the last week, very fine (heavy clay) soil
>95% prime time at its best hour, 80% that all 11 hours stay mowable. Every forecast run agrees.
Limiting factor:ground firmness
Monday 26 October: 11 hours worth using. 8am–7pm — dry since Friday by then, ground firm
Loading the hour-by-hour forecast…
Growth: growing steadily (growth potential 0.40). 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.
Monday 26 October · 8am–7pmReasonably confident
8am–7pm — dry since Friday by then, ground firm
>95% prime time at its best hour, 90% that all 11 hours stay mowable. Every forecast run agrees.
Limiting factor:none
Tuesday 27 October: 11 hours worth using. 8am–7pm — dry since Friday by then, ground firm
Loading the hour-by-hour forecast…
Growth: growing steadily (growth potential 0.40). 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.
Tuesday 27 October · 8am–7pmReasonably confident
8am–7pm — dry since Friday by then, ground firm
95% prime time at its best hour, 80% that all 11 hours stay mowable. A handful of runs found the grass too wet.
Limiting factor:none
Wednesday 28 October: 11 hours worth using. 8am–7pm — dry since Friday by then, ground firm
Loading the hour-by-hour forecast…
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.
Wednesday 28 October · 8am–7pmLow confidence this far out
8am–7pm — dry since Friday by then, ground firm
95% prime time at its best hour, 75% that all 11 hours stay mowable. A handful of runs found the grass too wet.
Limiting factor:none
Thursday 29 October: 10 hours worth using. 8am–6pm — grass dry — dry again after a shower
Loading the hour-by-hour forecast…
Growth: growing slowly (growth potential 0.34). 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.
Thursday 29 October · 8am–6pmLow confidence this far out
8am–6pm — grass dry — dry again after a shower
85% good to go at its best hour, 60% that all 10 hours stay mowable. About 1 run in 6 found the grass too wet.
Limiting factor:grass wetness
good to go touch and go dark, frost or snow already goneFainter means fewer forecast runs agree.
Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows under it in each day's table 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 hit.
Growth
How fast it is growing, and when it will need cutting again.
62%Growing strongly
Of the fastest this grass could grow. The turf-industry measure, from today's temperature and day length.
Roughly 2mm a day. A lawn cut today would be ready for another in a fortnight or so.
Held back by day length, not temperature — 10.9 hours of daylight. Warm weather will not change that much.
- Over the next 10 days
- about 15mm of leaf
- Next cut due
- in a fortnight or so
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 Salt Lake City, Utah
56°F13.1°C
at 6cm — germination depth
Seeding conditions are open — soil is 13.1°C at 6cm and holding above 12.5°C.
Cooling over the next 10 days.
Cross-checks against an independent estimate from air temperature (14.5°C), which agrees to within 1.1°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 use 12.5°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 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.
Salt Lake City, Utah in detail
Soil temperature in Salt Lake City, Utah is currently 13.1°C at 6cm, and falling about 5.3°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 13.1°C at 6cm and holding above 12.5°C.
8 of the next 10 days are good mowing days. The other 2 are held back by wet grass or soft ground. The best weekend slot right now is Sunday 8am–7pm, on the basis that ground firm — 27mm rain over the last week, very fine (heavy clay) soil.
The next recommended window in Salt Lake City opens at 8am on Tuesday 20 October, because that is first light. Underfoot, the ground reads as firm after 10mm rain over the last week, very fine (heavy clay) soil.
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 82 forecast runs from NCEP GEFS, 25km 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.