Mertzon (12 mi NNW), Texas climate: Climate normals at a NOAA weather station
Mertzon (12 mi NNW)'s normal year runs from 29°F January nights to 95°F August afternoons, with 21.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 17.7°C, January lows of −1°C, August highs of 35°C, 548 mm of precipitation a year.
- NOAA stationMertzon (12 mi NNW)
- Station IDUSC00415861
- Location31.44°N 100.88°W
- Elevation2,205 ft (672 m)
On October 23, the normal high in Mertzon (12 mi NNW) is 77°F and the normal low 48°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mertzon (12 mi NNW).
- Jan 58° 29°
- Feb 64° 33°
- Mar 71° 41°
- Apr 80° 49°
- May 87° 59°
- Jun 93° 67°
- Jul 94° 70°
- Aug 95° 69°
- Sep 87° 62°
- Oct 80° 51°
- Nov 68° 39°
- Dec 60° 31°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Mertzon (12 mi NNW) each month?
August is the warmest month, with normal highs of 95°F; January the coldest, with normal lows of 29°F. The most precipitation falls in May (2.64 in), the least in January (0.89 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 58°F | 29°F | 43.8°F | 0.89 | – | <1 | 22 | 10 h 20 min |
| February | 64°F | 33°F | 48.3°F | 1.03 | – | <1 | 14 | 11 h |
| March | 71°F | 41°F | 55.5°F | 1.52 | – | 1 | 8 | 12 h |
| April | 80°F | 49°F | 64.0°F | 1.57 | – | 6 | 2 | 12 h 50 min |
| May | 87°F | 59°F | 72.7°F | 2.64 | – | 13 | <1 | 13 h 40 min |
| June | 93°F | 67°F | 80.0°F | 2.54 | – | 24 | <1 | 14 h 10 min |
| July | 94°F | 70°F | 81.9°F | 1.90 | – | 26 | <1 | 14 h |
| August | 95°F | 69°F | 82.0°F | 2.35 | – | 27 | <1 | 13 h 20 min |
| September | 87°F | 62°F | 74.7°F | 2.59 | – | 14 | <1 | 12 h 20 min |
| October | 80°F | 51°F | 65.2°F | 2.17 | – | 4 | 2 | 11 h 30 min |
| November | 68°F | 39°F | 53.2°F | 1.47 | – | <1 | 9 | 10 h 40 min |
| December | 60°F | 31°F | 45.4°F | 0.90 | – | <1 | 17 | 10 h 10 min |
| Year (annual) | 78°F | 50°F | 63.9°F | 21.57 | – | 116 | 74 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 15°C | −1°C | 6.6°C | 23 mm |
| February | 18°C | 1°C | 9.1°C | 26 mm |
| March | 21°C | 5°C | 13.1°C | 39 mm |
| April | 26°C | 9°C | 17.8°C | 40 mm |
| May | 31°C | 15°C | 22.6°C | 67 mm |
| June | 34°C | 20°C | 26.7°C | 65 mm |
| July | 35°C | 21°C | 27.7°C | 48 mm |
| August | 35°C | 21°C | 27.8°C | 60 mm |
| September | 31°C | 17°C | 23.7°C | 66 mm |
| October | 26°C | 11°C | 18.4°C | 55 mm |
| November | 20°C | 4°C | 11.8°C | 37 mm |
| December | 16°C | −1°C | 7.4°C | 23 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Water Valley (19 miles away), gets 2 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00415861; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Mertzon (12 mi NNW)?
Normal highs sit between 65°F and 85°F in March, April, October and November.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00415861.
When is the last frost at Mertzon (12 mi NNW)?
In Mertzon (12 mi NNW), the last spring frost (32°F) comes after April 1 in half of years and after April 19 in one year in ten; the first autumn frost comes before November 4 in half of years and before October 21 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 11 year in 10 after April 19; 9 in 10 after March 14
- First autumn frost, half of years before
- November 41 year in 10 before October 21; 9 in 10 before November 18
NOAA puts the median frost-free season at 215 days, and the season without a hard freeze (28°F) at 237 days.
A hard freeze (28°F) comes after March 19 in half of springs and before November 12 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mertzon (12 mi NNW) in zone 8a in ZIP code 76902, the nearest ZIP area.
Frost dates for every NOAA station in Texas · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00415861; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Mertzon (12 mi NNW)?
In a normal year in Mertzon (12 mi NNW), 116 days a year reach 90°F (26 of them 100°F or more) and 74 nights fall to 32°F or colder.
- Days at 90°F or more
- 116a normal year
- Days at 100°F or more
- 26a normal year
- Nights at 32°F or colder
- 74a normal year
- Days that stay below freezing
- 4high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00415861.
How sunny is it at Mertzon (12 mi NNW)?
Over a year 84% of the sunlight that would reach the ground under clear skies gets through the clouds at Mertzon (12 mi NNW), 5.2 kWh per square metre a day. June is the sunniest month (89%) and February the cloudiest (78%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 80% | 3.3 |
| February | 78% | 4.1 |
| March | 79% | 5.2 |
| April | 83% | 6.3 |
| May | 82% | 6.6 |
| June | 89% | 7.3 |
| July | 88% | 7.0 |
| August | 88% | 6.5 |
| September | 83% | 5.3 |
| October | 83% | 4.5 |
| November | 82% | 3.5 |
| December | 80% | 3.0 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Mertzon (12 mi NNW) record?
A normal year at Mertzon (12 mi NNW) brings 2,691 heating degree days, 50% fewer than the median U.S. place (5,373), and 2,313 cooling degree days, 2.5 times the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,829 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 660 | 1 |
| February | 473 | 6 |
| March | 317 | 22 |
| April | 119 | 89 |
| May | 28 | 267 |
| June | 0 | 450 |
| July | 0 | 524 |
| August | 0 | 527 |
| September | 9 | 300 |
| October | 109 | 115 |
| November | 367 | 12 |
| December | 608 | 1 |
| Year (annual) | 2,691 | 2,313 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00415861. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Mertzon (12 mi NNW) been warmer than normal?
2022 averaged 64.9°F, 1.0°F above the 1991-2020 normal of 63.9°F. 1 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 63.9°F | at normal | 23.80 |
| 2022 | 64.9°F | +1.0°F | 12.89 |
Source: observed years: ACIS, station USC00415861. A year counts only with all twelve months complete.
How does Mertzon (12 mi NNW)'s climate compare?
Mertzon (12 mi NNW) is warmer than 91 of the 321 places with their own NOAA record in Texas, and wetter than 70. Across the 7,247 U.S. stations with normals, its annual mean of 63.9°F is warmer than 85%.
In the Köppen classification computed from these normals, Mertzon (12 mi NNW) is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Mertzon (12 mi NNW) share this climate record?
Mertzon has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Mertzon, TX762 people · 12 mi S
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Mertzon (12 mi NNW)'s climate
What is the coldest month at Mertzon (12 mi NNW)?
January, with a normal high of 58°F and a normal low of 29°F. The warmest is August (95°F by day, 69°F at night).
Does it snow at Mertzon (12 mi NNW)?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Water Valley (19 miles away), records 2 inches of snow in a normal year.
What is the rainiest month at Mertzon (12 mi NNW)?
May, with 2.64 in of precipitation in a normal year; the driest is January with 0.89 in.
What plant hardiness zone is Mertzon (12 mi NNW) in?
The USDA's 2023 map puts Mertzon (12 mi NNW) in zone 8a in ZIP code 76902, the nearest ZIP area.
How late can frost come at Mertzon (12 mi NNW)?
In half of years the last 32°F night comes after April 1; in one year in ten it comes after April 19. Waiting until April 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Texas climateThe statewide normals and every place in the state
- Water Valley, TX19 miles from this station, 64.7°F a year
- San Angelo, TX23 miles from this station, 66.7°F a year
- Cope Ranch, TX25 miles from this station, 63.2°F a year
- Sterling City, TX28 miles from this station, 63.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made