Mertzon, TX Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from Mertzon's primary NOAA station, MERTZON 12NNW.
The climate verdict for Mertzon
Mertzon, Texas has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 64°F. It scores 92/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 92% of them.
- 64°F
- yearly average temperature, NOAA normal
- 92/100
- comfort score, above 92% of station-mapped location scores
- 21.6"
- yearly precipitation total
- 217 days
- growing season, frost-free days
Mertzon: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00415861 · Mertzon, TX 64°F mean · 21.6" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-DRY · SWING-MID · COMF-TOP · LOAD-MIX · STN-1 · BOOK-FULL
- TEMP-MILD 64°F
- RANK-UPPER #5,832
- PHOTO-FINISH ≈ Balmorhea
- PRCP-DRY 21.6"
- SWING-MID 38°F
- COMF-TOP 92/100
- LOAD-MIX H/C balanced
- STN-1 USC00415861
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Balmorhea, TX (+ 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 TX station list.
- Mertzon (this station) 64°F
- Hot Eden, TX 64°F
- Near Balmorhea, TX 64°F
- Near Birmingham, AL 64°F
- Near Blackville, SC 64°F
Mertzon 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 · Mertzon
Mertzon: 63/100 · grade C
Mertzon publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Mertzon, not an official NOAA rating. Rankings still use Comfort Score 92/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Annual temperature balance | 63.9°F · 3.6° from 67.5°F | 89/100 · A |
| Frost-free season | 217 days/year | 76/100 · B |
| Precipitation balance | 21.6 in · 13.4 from 35 in | 53/100 · D |
| Normal heat + freeze calendar | 163 calendar days | 37/100 · F |
Mertzon · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Mertzon is a temperate Köppen climate: Cfa
Coldest-month mean 43.8°F and warmest-month mean 82.0°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
- 82.0°F
- Coldest month
- 43.8°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 Mertzon sits across the climate record
Three NOAA fields for Mertzon's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Top 15% warmest
- Among 6,861 stations, Mertzon sits in the warmer third of annual means.
- Annual precipitation
- Drier than 70%
- Mertzon's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Narrower than 72%
- Warmest-to-coldest month gap for Mertzon is compact versus 6,861 complete station-years.
How Mertzon compares across U.S. station-mapped locations
Mertzon's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
92 Top 8% score exceeds 92% 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
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 58°F (15°C) | 29°F (-1°C) | 44°F (7°C) | 0.9" | 22.1 | 0.0 |
| February | 64°F (18°C) | 33°F (1°C) | 48°F (9°C) | 1.0" | 14.4 | 0.3 |
| March | 71°F (21°C) | 41°F (5°C) | 56°F (13°C) | 1.5" | 7.7 | 1.2 |
| April | 80°F (26°C) | 49°F (9°C) | 64°F (18°C) | 1.6" | 1.6 | 6.4 |
| May | 87°F (31°C) | 59°F (15°C) | 73°F (23°C) | 2.6" | 0.2 | 13.0 |
| June | 93°F (34°C) | 67°F (20°C) | 80°F (27°C) | 2.5" | 0.0 | 24.2 |
| July | 94°F (35°C) | 70°F (21°C) | 82°F (28°C) | 1.9" | 0.0 | 26.1 |
| August | 95°F (35°C) | 69°F (21°C) | 82°F (28°C) | 2.4" | 0.0 | 26.6 |
| September | 87°F (31°C) | 62°F (17°C) | 75°F (24°C) | 2.6" | 0.0 | 13.5 |
| October | 80°F (26°C) | 51°F (11°C) | 65°F (18°C) | 2.2" | 2.1 | 4.3 |
| November | 68°F (20°C) | 39°F (4°C) | 53°F (12°C) | 1.5" | 9.4 | 0.2 |
| December | 60°F (16°C) | 31°F (-1°C) | 45°F (7°C) | 0.9" | 16.5 | 0.0 |
The year, day by day
Mertzon works both ends of the calendar. Normal highs climb to 96°F by August 4 and hold at or above 90°F on 101 dates, then normal lows drop to freezing or below on 62 dates, bottoming at 29°F around January 5.
When the heat sits
Normal highs reach 90°F from May 27 through September 4, covering 101 dates. The broader mild season, normal highs of 70°F or more, runs March 15 to November 8.
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.
The freezing stretch
The normal low stays at or below 32°F into February 8, then returns to freezing around December 9, covering 62 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
The widest day
April 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 Mertzon.
Where Mertzon Stands Nationally
Summers here run among the most heat-heavy normals calendars in the country: on about 101 days a year the normal daily high itself reaches 90°F — a count fewer than one station in ten exceeds.
Mertzon earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall
Mertzon spreads its precipitation across the year
Neither half of the year dominates here: June through August take 31% of the annual total and December through February 13%, with neither reaching the 35% that would mark a distinct wet season. Mertzon has no dry season to plan around, though it does carry a 38.2°F seasonal spread.
The gap between the wettest and driest month still matters: May averages 2.6" and January 0.9". The three wettest months together take 36% 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.
Frost Dates & Growing Season
First Fall Freeze
November 4
50% probability date
Last Spring Freeze
April 1
50% probability date
Growing Season
217 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
2,691
Higher = more heating needed
Cooling Degree Days
2,313
Higher = more cooling needed
Warmest Month
August
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside TX closest to Mertzon 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 (64°F here).
- Birmingham, AL 64°F · 0.0°F off
- Blackville, SC 64°F · 0.0°F off
- Gainesville, AL 64°F · 0.0°F off
- Hanford, CA 64°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (21.6" here), excluding temperature-peer places.
- Johnson Siding, SD 21.6" · 0.0" off
- Soldotna, AK 21.6" · 0.0" off
- Kyle, SD 21.6" · 0.0" off
- Kaltag, AK 21.5" · 0.0" off
Data-derived climate profile
How Mertzon's climate pattern fits together
mixed demand · moderate · mid swing
August and January mark the typical warm and cold ends of the calendar in Mertzon's middle-range seasonal profile. The measured spread is 38.2°F. The annual average is 64°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Heating and cooling both register in Mertzon's normal, at 2,691 and 2,313 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.
A roughly 217-day frost-free season sits inside this mixed heating-and-cooling profile. Start and end dates matter because both sides of the thermostat register during a normal year.
Mertzon's 21.6 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Snowfall is not added to the interpretation because its annual value is missing. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
These labels group NOAA 1991-2020 normals from Mertzon's primary station, where heating and cooling demand are close enough that neither season sets the character on its own. On a balanced station like Mertzon, the bands are descriptive ranges rather than an official NOAA classification or a forecast.
Questions about Mertzon's climate
How much rain does Mertzon get? ▼
How many days above 90°F does Mertzon get? ▼
How much energy does heating and cooling require in Mertzon? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Mertzon's primary station: MERTZON 12NNW (USC00415861). 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 4847832). Match rule for Mertzon: 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 Mertzon 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.