Port Isabel, TX Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Port Isabel's primary NOAA station, PORT ISABEL.
The climate verdict for Port Isabel
Warm-season cooling demand defines Port Isabel, Texas, running at more than twice its heating total. The NOAA normal records an annual average of 74°F. It scores 100/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 99% of them.
- 74°F
- average temperature, NOAA 1991-2020 normal
- 100/100
- comfort score, above 99% of station-mapped location scores
- 28.8"
- yearly precipitation total
Port Isabel: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00417179 · Port Isabel, TX 74°F mean · 28.8" precip
TEMP-HOT · RANK-WARM · PHOTO-FINISH · PRCP-MID · SWING-NARROW · COMF-TOP · LOAD-COOL · STN-1 · BOOK-FULL
- TEMP-HOT 74°F
- RANK-WARM #6,724
- PHOTO-FINISH ≈ Bradenton
- PRCP-MID 28.8"
- SWING-NARROW 24°F
- COMF-TOP 100/100
- LOAD-COOL 3,837 CDD
- STN-1 USC00417179
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Bradenton, FL (+ 0.1 °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 TX station list.
- Port Isabel (this station) 74°F
- Cold Clermont, FL 74°F
- Hot Wfo Brownsville, TX 74°F
- Near Bradenton, FL 74°F
- Near Plant City, FL 74°F
Port Isabel sits in Texas, the #4 hottest U.S. state at 66.2°F statewide annual average - see all 50 hottest states ranked by NOAA normals
Climate Living Index · Port Isabel
Port Isabel: 81/100 · grade B
Port Isabel publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Port Isabel, not an official NOAA rating. Rankings still use Comfort Score 100/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Snowfall burden | 0.2 inches/year | 89/100 · A |
| Annual temperature balance | 74.0°F · 6.5° from 67.5°F | 80/100 · B |
| Normal heat + freeze calendar | 87 calendar days | 80/100 · B |
| Precipitation balance | 28.8 in · 6.3 from 35 in | 78/100 · B |
Port Isabel · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Port Isabel is a temperate Köppen climate: Cfa
Coldest-month mean 60.3°F and warmest-month mean 84.5°F place this station in temperate, no dry season, hot summer climates (Cfa). Class Cfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, no dry season, hot summer.
- Köppen code
- Cfa
- Group
- Temperate
- Warmest month
- 84.5°F
- Coldest month
- 60.3°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 · cooling-led station
Where Port Isabel sits across the climate record
Three NOAA fields for Port Isabel's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Top 2% warmest
- Among 6,861 stations, Port Isabel sits in the warmer third of annual means.
- Annual precipitation
- 39th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 95%
- Warmest-to-coldest month gap for Port Isabel is compact versus 6,861 complete station-years.
How Port Isabel compares across U.S. station-mapped locations
Port Isabel's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
100 Top 1% score exceeds 99% 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%). Below this entry.
- 90–100: 564 station-mapped locations (9%). This entry sits in this band.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Port Isabel's measured station temperature trend
MethodologyAcross 39 complete annual observations from 1930 to 2025, PORT ISABEL warmed at a fitted rate of 0.18°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Port Isabel primary station fitted change +0.18 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 69°F (21°C) | 52°F (11°C) | 60°F (16°C) | 1.4" | 0.0" | 0.2 | 0.0 |
| February | 72°F (22°C) | 56°F (13°C) | 64°F (18°C) | 1.2" | 0.0" | 0.3 | 0.1 |
| March | 76°F (24°C) | 61°F (16°C) | 68°F (20°C) | 1.7" | 0.0" | 0.1 | 0.5 |
| April | 81°F (27°C) | 67°F (19°C) | 74°F (23°C) | 1.6" | 0.0" | 0.0 | 0.8 |
| May | 86°F (30°C) | 73°F (23°C) | 79°F (26°C) | 2.4" | 0.0" | 0.0 | 5.5 |
| June | 90°F (32°C) | 76°F (25°C) | 83°F (28°C) | 3.1" | 0.0" | 0.0 | 18.7 |
| July | 91°F (33°C) | 77°F (25°C) | 84°F (29°C) | 2.3" | 0.0" | 0.0 | 22.9 |
| August | 92°F (33°C) | 77°F (25°C) | 85°F (29°C) | 1.9" | 0.0" | 0.0 | 26.6 |
| September | 89°F (31°C) | 74°F (23°C) | 81°F (27°C) | 6.2" | 0.0" | 0.0 | 15.1 |
| October | 85°F (30°C) | 69°F (21°C) | 77°F (25°C) | 3.9" | 0.0" | 0.0 | 4.8 |
| November | 78°F (25°C) | 61°F (16°C) | 69°F (21°C) | 1.8" | 0.0" | 0.1 | 0.0 |
| December | 71°F (21°C) | 54°F (12°C) | 62°F (17°C) | 1.4" | 0.2" | 0.1 | 0.0 |
The year, day by day
The year in Port Isabel runs from a mild 51°F around January 7 to 93°F at the peak near August 7, and the normal low never reaches freezing on any date in the record.
When the heat sits
Normal highs reach 90°F from June 10 through September 4, covering 87 dates. The broader mild season, normal highs of 70°F or more, runs January 29 to December 18.
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 51°F around January 7.
Where the wet dates fall
The likeliest wet date is January 1, when 31% of years recorded at least a hundredth of an inch. The driest is July 29 at 9%. Summed across the calendar, that is about 68 wet dates a year.
The widest day
January 4 carries the biggest normal gap between afternoon and dawn, 17°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Port Isabel.
Where Port Isabel Stands Nationally
Among the steadiest day-night climates ranked: even the widest normal daily swing holds to roughly 17°F.
Heat is a defining feature of the normals calendar — the normal daily high reaches 90°F on roughly 87 days a year, more than four out of five ranked stations record.
Port Isabel earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall and snowfall
7.9 days with precipitation
5.2 days with precipitation
4.8 days with precipitation
3.6 days with precipitation
4.0 days with precipitation
4.0 days with precipitation
3.6 days with precipitation
4.4 days with precipitation
8.3 days with precipitation
7.3 days with precipitation
5.8 days with precipitation
Snow: 0.2"
7.7 days with precipitation
Port Isabel spreads its precipitation across the year
Neither half of the year dominates here: June through August take 25% of the annual total and December through February 14%, with neither reaching the 35% that would mark a distinct wet season. Port Isabel has no dry season to plan around, though it does carry an unusually narrow 24.2°F seasonal spread.
The gap between the wettest and driest month still matters: September averages 6.2" and February 1.2". The three wettest months together take 45% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
When it rains in Port Isabel, it arrives in quantity
28.8" of precipitation falls across only about 67 wet days here, averaging 0.43 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 67 a year, 18% of all days
- Average depth per wet day
- 0.43 inches
- Most wet days
- September, about 8
- Fewest wet days
- April, about 4
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Snow reaches Port Isabel, but rarely amounts to much
The normals record 0.2 inches of snow a year here, most likely in December. That is a real but marginal amount: enough that snow is part of the local record, not enough to define the winter.
A figure in this range usually reflects a handful of events that melt quickly rather than a season of accumulation.
NOAA 1991-2020 normals. An average across thirty years can smooth away a single heavy winter, so a small annual figure does not mean a significant snowfall is impossible.
Frost Dates & Growing Season
First Fall Freeze
January 1
50% probability date
Last Spring Freeze
January 3
50% probability date
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
551
Higher = more heating needed
Cooling Degree Days
3,837
Higher = more cooling needed
Warmest Month
August
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside TX closest to Port Isabel 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 (74°F here).
- Clewiston, FL 74°F · 0.0°F off
- Hilo, HI 74°F · 0.0°F off
- Bradenton, FL 74°F · 0.1°F off
- Ehrenberg, AZ 74°F · 0.1°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (28.8" here), excluding temperature-peer places.
- Howells, NE 28.8" · 0.0" off
- Hudson, KS 28.7" · 0.0" off
- Osceola, NE 28.8" · 0.0" off
- Taloga, OK 28.8" · 0.1" off
Data-derived climate profile
How Port Isabel's climate pattern fits together
cooling led · moderate · low swing
Warm-season load persists through a relatively even calendar in Port Isabel. Cooling totals 3,837 degree days, more than double the 551 heating measure, and the 24.2°F seasonal range is compact rather than sharply divided.
Port Isabel's 28.8 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Recorded annual snowfall is negligible. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
Temperature varies within a narrow 24.2°F band across the normal year. August and January mark the typical warm and cold ends of the calendar. The annual average is 74°F. Monthly rows still matter, but they refine a steady profile rather than reveal two climatic extremes.
A frost-free growing-season length is not available for Port Isabel. That missing field is kept separate from the observed temperature and precipitation record rather than filled from a regional estimate.
These labels group NOAA 1991-2020 normals from Port Isabel's primary station, so the summer figures are a thirty-year average rather than a ceiling: individual years have run hotter and will again. For Port Isabel that means a descriptive range only — not an official NOAA classification and not a prediction for next summer.
Questions about Port Isabel's climate
How much rain does Port Isabel get? ▼
How many days above 90°F does Port Isabel get? ▼
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Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Port Isabel's primary station: PORT ISABEL (USC00417179). 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 4858892). Match rule for Port Isabel: 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 Port Isabel 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.