The weather station for Porterville has not reported for 5 days, so this page may be out of date.
What to do in Porterville now
Porterville is in warm-season grass country. Dates are typical for this spot, worked out from 12 years of weather at Porterville Municipal Airport; each status uses this year's soil estimates.
Cool-season: tall fescue, Kentucky bluegrass, perennial ryegrass, fine fescue
- Crabgrass pre-emergent Closed Feb 28 Typical: early Feb – Feb 152-inch soil held 55°F for a week from Feb 28, so crabgrass was sprouting. Next window: about Feb 1 – Feb 15, 2027.
- Seed or overseed Seed now · about 27 days left Typical: Aug 10 – Nov 264-inch soil is 64°, inside the 55–70°F range where tall fescue and bluegrass sprout fastest. The window typically closes around Nov 26.
- Late-fall feeding Soil rarely cools to 40°F Typical: Through winterRoots stay active through most winters here. Feed on the fall schedule your extension office gives for your grass, and avoid feeding a lawn that is dormant from drought.
Warm-season: bermudagrass, zoysia, St. Augustine, centipede, bahia
- Crabgrass pre-emergent Closed Feb 28 Typical: early Feb – Feb 152-inch soil held 55°F for a week from Feb 28, so crabgrass was sprouting. Next window: about Feb 1 – Feb 15, 2027.
- Seed or sod Wait for late spring Typical: May 5 – Aug 10Warm-season seed needs 4-inch soil at 65°F or more, and seedlings need the rest of summer to establish. Next window opens about May 5.
- Fall pre-emergent (Poa annua) Germinating since Oct 22 Typical: By Aug 104-inch soil fell below 70°F on Oct 22, when annual bluegrass begins to sprout. A pre-emergent now only stops later flushes; plan to apply by about Aug 10 next year.
- Dormancy and last feeding Expected about Nov 26 Typical: Around Nov 26Warm-season grass slows and browns once 4-inch soil stays under 55°F, typically Nov 26. Make the last nitrogen feeding at least a month before that.
The last 60 days and the week ahead
Porterville soil is 1° warmer than normal for Oct 30, warmer than on 78% of those dates since 2005, and 1° cooler than a year ago.
The green line is our estimate of the daily average soil temperature 2 inches down, driven by temperatures at Porterville Municipal Airport, 4.6 km from the city center. The dashed part runs the National Weather Service forecast through the same model. Hover or tap for any day.
2-inch soil, estimated From the NWS forecast Normal Normal range (8 years in 10)
Show the numbers
| Date | 2-inch soil | 4-inch soil | Air high / low | Normal (2 in) |
|---|---|---|---|---|
| Oct 10 | 79° | 81° | 85° / 56° | 64° |
| Oct 11 | 75° | 78° | 78° / 55° | 64° |
| Oct 12 | 71° | 75° | 72° / 53° | 64° |
| Oct 13 | 68° | 72° | 75° / 44° | 63° |
| Oct 14 | 67° | 70° | 80° / 47° | 63° |
| Oct 15 | 67° | 70° | 85° / 48° | 63° |
| Oct 16 | 68° | 70° | 90° / 50° | 63° |
| Oct 17 | 69° | 71° | 92° / 50° | 63° |
| Oct 18 | 70° | 71° | 92° / 53° | 63° |
| Oct 19 | 70° | 71° | 88° / 52° | 63° |
| Oct 20 | 68° | 70° | 79° / 48° | 63° |
| Oct 21 | 65° | 68° | 63° / 53° | 62° |
| Oct 22 | 65° | 67° | 73° / 55° | 62° |
| Oct 23 | 64° | 66° | 68° / 55° | 62° |
| Oct 24 | 64° | 66° | 73° / 53° | 62° |
| Oct 25 | 64° | 66° | 78° / 49° | 62° |
| Oct 26 | 63° | 65° | 78° / 47° | 62° |
| Oct 27 | 62° | 64° | 73° / 45° | 61° |
| Oct 28 | 61° | 63° | 71° / 45° | 61° |
| Oct 29 | 61° | 63° | 72° / 50° | 61° |
| Oct 30 | 62° | 64° | 75° / 55° | 61° |
Which grass grows in Porterville
With mild winters (January averages 48°F), most Porterville lawns are warm-season grasses such as bermudagrass, St. Augustine, zoysia and centipede. They grow through summer and slow or go dormant in winter.
Porterville soil through the year
Weekly 2-inch estimates for 2026 so far against 2025 and the normal for each week. The red lines mark 50°F, when crabgrass pre-emergent should be down, and 65°F, when warm-season seed sprouts well.
2026 2025 Normal (2005–2025) 8 years in 10
Normal by month
| Month | 2 in | 4 in | Air |
|---|---|---|---|
| Jan | 54° | 55° | – |
| Feb | 55° | 56° | – |
| Mar | 57° | 58° | – |
| Apr | 60° | 61° | – |
| May | 64° | 65° | – |
| Jun | 67° | 68° | – |
| Jul | 72° | 73° | – |
| Aug | 71° | 72° | – |
| Sep | 68° | 70° | – |
| Oct | 63° | 65° | – |
| Nov | 58° | 59° | – |
| Dec | 54° | 55° | – |
Soil: average of our daily estimates, 2005–2025. Air: NOAA 1991–2020 normals for the station.
Typical lawn dates in Porterville
Each date is when the soil estimate (or the air, for freezes) crossed the threshold, year by year since 2005. “Early” and “late” are the 10th and 90th percentile years, so 8 years in 10 fall between them.
| Event | Typical | 2026 |
|---|---|---|
| Crabgrass model: 250 growing degree days (in 11 of 21 years) | Jan 18 | Jan 14 |
| Pre-emergent window opens (2-inch soil 50°F) | early Feb | Feb 3 |
| Crabgrass begins to sprout (2-inch soil 55°F) | Feb 15 | Feb 28 |
| Cool-season lawns start growing (4-inch soil 55°F) | Feb 1 | Feb 11 |
| Warm-season seeding opens (4-inch soil 65°F) (in 11 of 21 years) | May 5 | Mar 19 |
| Cool-season seeding opens (4-inch soil under 70°F) | Aug 10 | Oct 22 |
| Cool-season seeding ends (4-inch soil under 55°F) (in 11 of 21 years) | Nov 26 | not yet |
| Warm-season grass goes dormant (4-inch under 55°F) (in 11 of 21 years) | Nov 26 | not yet |
Where these numbers come from
There is no soil sensor in most cities, so we estimate it. Shallow soil follows air temperature with a lag of a few days, and runs a little warmer than the air in fall. We fitted that relationship to 190 USDA soil-sensor stations; on years held out of the fit, the estimate was off by 3.3°F on an average day, and it put the spring 55°F date within a median of 3 days. Read the methodology.
Weather: RCC ACIS station KPTV (PORTERVILLE MUNICIPAL AIRPORT), daily data since 2000. Forecast: National Weather Service, HNX office, issued Nov 4, 2026, 6:56 AM EST. Last observed day: Oct 30, 2026.
Porterville questions
What is the soil temperature in Porterville today? Our estimate for Oct 30 is 62°F at 2 inches and 64°F at 4 inches, as a daily average. Early-morning soil runs a few degrees cooler than that, and afternoon soil warmer.
When should I put down crabgrass pre-emergent in Porterville? Apply when 2-inch soil holds about 50°F and before it holds 55°F. That has typically been early Feb to Feb 15 in Porterville. For 2026 the window closed on Feb 28.
When can I seed bermudagrass in Porterville? Wait for late spring. Warm-season seed needs 4-inch soil at 65°F or more, and seedlings need the rest of summer to establish. Next window opens about May 5.
Is it too late to fertilize in Porterville? Expected about Nov 26. Warm-season grass slows and browns once 4-inch soil stays under 55°F, typically Nov 26. Make the last nitrogen feeding at least a month before that.
When is the last frost in Porterville? The last 32°F night of spring has typically come around Mar 18, and as late as May 12 in 1 year in 10. The first fall freeze typically arrives around Dec 2.
Why 2 inches and 4 inches? Crabgrass and most weed seeds sprout in the top inch or two, so pre-emergent timing follows 2-inch soil. Grass seed and roots respond to the slightly steadier soil at about 4 inches.
How accurate is this? It is a model, not a probe in your yard. Expect about 3–4°F of difference on a given day; shade, slope, mulch and irrigation all move real soil. The dates and trends are more reliable than any single day.