Porterville, CA Climate: Temperature & Rain by Month
Average temperature and precipitation from NOAA NCEI 1991–2020 normals →, with a derived climate comfort score
30-year climate normals (1991-2020) from Porterville's primary NOAA station, PORTERVILLE.
The climate verdict for Porterville
Dryness leads the climate profile for Porterville, California, with 11.0 inches of precipitation a year. NOAA records an annual average of 66°F. It scores 88/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 89% of them.
- 66°F
- average temperature, NOAA 1991-2020 normal
- 88/100
- comfort score, above 89% of station-mapped location scores
- 11.0"
- yearly precipitation total
- 327 days
- growing season, frost-free days
Porterville: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00047077 · Porterville, CA 66°F mean · 11.0" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-ARID · SWING-MID · COMF-TOP · LOAD-MIX · STN-1 · BOOK-FULL
- TEMP-MILD 66°F
- RANK-UPPER #6,106
- PHOTO-FINISH ≈ Aguila
- PRCP-ARID 11.0"
- SWING-MID 34°F
- COMF-TOP 88/100
- LOAD-MIX H/C balanced
- STN-1 USC00047077
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Aguila, AZ (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every CA station list.
- Porterville (this station) 66°F
- Hot Corsicana, TX 66°F
- Near Aguila, AZ 66°F
- Near Barstow, CA 66°F
- Near Centerville, TX 66°F
Climate Living Index · Porterville
Porterville: 70/100 · grade B
Porterville publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Porterville, not an official NOAA rating. Rankings still use Comfort Score 88/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Frost-free season | 327 days/year | 100/100 · A |
| Annual temperature balance | 65.7°F · 1.8° from 67.5°F | 94/100 · A |
| Normal heat + freeze calendar | 114 calendar days | 68/100 · C |
| Precipitation balance | 11.0 in · 24.0 from 35 in | 15/100 · F |
Porterville · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Porterville's normals sit in a dry climate class: BSh
Precipitation is low relative to temperature but above true desert thresholds: hot semi-arid steppe (BSh). Class BSh is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically hot semi-arid steppe.
- Köppen code
- BSh
- Group
- Dry (arid or semi-arid)
- Warmest month
- 83.4°F
- Coldest month
- 49.0°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · balanced station
Where Porterville sits across the climate record
Three NOAA fields for Porterville's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Top 11% warmest
- Among 6,861 stations, Porterville sits in the warmer third of annual means.
- Annual precipitation
- Drier than 92%
- Porterville's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Narrower than 84%
- Warmest-to-coldest month gap for Porterville is compact versus 6,861 complete station-years.
How Porterville compares across U.S. station-mapped locations
Porterville's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
88 Top 11% score exceeds 89% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). Below this entry.
- 70–80: 650 station-mapped locations (11%). Below this entry.
- 80–90: 921 station-mapped locations (15%). This entry sits in this band.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 59°F (15°C) | 40°F (4°C) | 49°F (10°C) | 2.1" | 5.6 | 0.0 |
| February | 65°F (18°C) | 43°F (6°C) | 54°F (12°C) | 1.9" | 1.5 | 0.0 |
| March | 71°F (21°C) | 47°F (8°C) | 59°F (15°C) | 2.0" | 0.2 | 0.1 |
| April | 76°F (24°C) | 50°F (10°C) | 63°F (17°C) | 0.9" | 0.1 | 2.9 |
| May | 84°F (29°C) | 56°F (13°C) | 70°F (21°C) | 0.3" | 0.0 | 10.3 |
| June | 93°F (34°C) | 63°F (17°C) | 78°F (25°C) | 0.1" | 0.0 | 20.8 |
| July | 98°F (37°C) | 68°F (20°C) | 83°F (29°C) | 0.1" | 0.0 | 29.5 |
| August | 97°F (36°C) | 67°F (19°C) | 82°F (28°C) | 0.0" | 0.0 | 28.8 |
| September | 92°F (34°C) | 62°F (17°C) | 77°F (25°C) | 0.1" | 0.0 | 22.1 |
| October | 82°F (28°C) | 53°F (12°C) | 68°F (20°C) | 0.6" | 0.0 | 7.5 |
| November | 68°F (20°C) | 44°F (7°C) | 56°F (13°C) | 0.9" | 1.4 | 0.0 |
| December | 59°F (15°C) | 39°F (4°C) | 49°F (9°C) | 1.9" | 6.5 | 0.0 |
The year, day by day
The year in Porterville runs from a mild 38°F around December 21 to 99°F at the peak near July 22, and the normal low never reaches freezing on any date in the record.
When the heat sits
Normal highs reach 90°F from June 5 through September 26, covering 114 dates. The broader mild season, normal highs of 70°F or more, runs March 13 to November 11.
This counts calendar dates whose 1991–2020 normal high reaches 90°F. It is a smaller number than the 90°F+ day counts in the monthly table above, which measure how often the threshold was actually crossed in a typical year. A date can average 88°F and still exceed 90°F in half of all years.
No freezing date
Not one calendar date in the 1991–2020 record carries a normal low at or below 32°F. The coldest normal low of the year is 38°F around December 21.
Where the wet dates fall
The likeliest wet date is February 13, when 32% of years recorded at least a hundredth of an inch. The driest is July 30 at 1%. Summed across the calendar, that is about 49 wet dates a year.
The widest day
August 14 carries the biggest normal gap between afternoon and dawn, 31°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Porterville.
Where Porterville Stands Nationally
Summers here run among the most heat-heavy normals calendars in the country: on about 114 days a year the normal daily high itself reaches 90°F — a count fewer than one station in ten exceeds.
Aridity defines the water calendar: about 11 inches in a normal year lands this among the driest tenth of ranked stations.
Porterville earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
9.4 days with precipitation
9.4 days with precipitation
7.0 days with precipitation
4.6 days with precipitation
2.4 days with precipitation
0.7 days with precipitation
0.2 days with precipitation
0.3 days with precipitation
1.0 days with precipitation
2.0 days with precipitation
4.6 days with precipitation
7.5 days with precipitation
Porterville's wet season runs through the cold months
December, January and February carry 54% of the year's precipitation here, while June through August contribute 1%. That is the cool-season-dominant pattern of the West Coast and the higher inland West, where storm tracks swing south in winter and summer turns dry; the thermometer meanwhile shows a 34.4°F seasonal spread.
- Wettest month
- January, 2.1"
- Driest month
- August, 0.0"
- Wettest three months
- January, March, December (55% of the year)
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A cool-season label means the December-February share reaches 35%. Where snow falls, the monthly figures above report liquid-equivalent precipitation, so a wet winter month is not necessarily a rainy one.
How Porterville's precipitation splits across the calendar
About 49 days a year record measurable precipitation here, carrying 11.0" between them, or roughly 0.22 inches on a typical wet day. That sits in the middle band: neither the many-light-days pattern of the Pacific Northwest and the Great Lakes, nor the few-heavy-events pattern of the Gulf and the desert Southwest.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
Frost Dates & Growing Season
First Fall Freeze
December 13
50% probability date
Last Spring Freeze
January 20
50% probability date
Growing Season
327 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
1,966
Higher = more heating needed
Cooling Degree Days
2,237
Higher = more cooling needed
Warmest Month
July
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside CA closest to Porterville on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (66°F here).
- Aguila, AZ 66°F · 0.0°F off
- Centerville, TX 66°F · 0.0°F off
- Corsicana, TX 66°F · 0.0°F off
- Eastman, GA 66°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (11.0" here), excluding temperature-peer places.
- McNeal, AZ 11.0" · 0.0" off
- Moro, OR 11.0" · 0.0" off
- Wickenburg, AZ 10.9" · 0.0" off
- Snowflake, AZ 11.0" · 0.1" off
Scarce-water calendar
Where Porterville's limited precipitation lands
mixed demand · dry · mid swing
Local precipitation is sparse in this otherwise mixed profile. The station reports 11.0 inches annually, within PlainClimate's dry band. Snowfall is not added to the interpretation because its annual value is missing. The monthly distribution matters because the total alone does not reveal the timing.
July and December mark the typical warm and cold ends of the calendar in Porterville's middle-range seasonal profile. The measured spread is 34.4°F. The annual average is 66°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Heating and cooling both register in Porterville's normal, at 1,966 and 2,237 degree days respectively. Neither total exceeds the other by more than two to one, so the record is better read as a mixed-demand calendar than as heating-led or cooling-led.
Porterville has a long frost-free window of roughly 327 days, but the dry annual profile is a separate constraint. Growing-season length says when freezes are unlikely, not whether rainfall is sufficient.
Porterville wettest normal
January
January concentrates the scarce annual total (11.0 inches).
Porterville driest normal
August
August is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about Porterville's climate
How dry is Porterville? ▼
How many days above 90°F does Porterville get? ▼
How much energy does heating and cooling require in Porterville? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Porterville's primary station: PORTERVILLE (USC00047077). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 0658240). Match rule for Porterville: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Porterville comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.