Somerville, Texas climate: Normal weather by month, frost dates and records
Somerville's normal year runs from 35°F January nights to 98°F August afternoons, with 41.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 19.4°C, January lows of 2°C, August highs of 37°C, 1,040 mm of precipitation a year.
- NOAA stationSomerville Dam
- Station IDUSC00418446
- Location30.34°N 96.54°W
- Elevation263 ft (80 m)
- Population1,478
On October 14, the normal high in Somerville is 84°F and the normal low 54°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Somerville.
- Jan 62° 35°
- Feb 66° 39°
- Mar 73° 46°
- Apr 80° 53°
- May 87° 62°
- Jun 93° 68°
- Jul 97° 70°
- Aug 98° 70°
- Sep 92° 64°
- Oct 83° 53°
- Nov 72° 44°
- Dec 64° 37°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Somerville each month?
August is the warmest month, with normal highs of 98°F; January the coldest, with normal lows of 35°F. The most precipitation falls in May (4.73 in), the least in July (1.88 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 62°F | 35°F | 48.6°F | 3.17 | 9 | <1 | 13 | 10 h 20 min |
| February | 66°F | 39°F | 52.4°F | 2.92 | 9 | <1 | 7 | 11 h 10 min |
| March | 73°F | 46°F | 59.2°F | 3.22 | 8 | <1 | 3 | 12 h |
| April | 80°F | 53°F | 66.3°F | 3.33 | 7 | 1 | <1 | 12 h 50 min |
| May | 87°F | 62°F | 74.2°F | 4.73 | 9 | 11 | <1 | 13 h 40 min |
| June | 93°F | 68°F | 80.7°F | 3.94 | 8 | 25 | <1 | 14 h 10 min |
| July | 97°F | 70°F | 83.5°F | 1.88 | 5 | 29 | <1 | 14 h |
| August | 98°F | 70°F | 83.9°F | 2.81 | 6 | 29 | <1 | 13 h 20 min |
| September | 92°F | 64°F | 78.1°F | 3.41 | 7 | 22 | <1 | 12 h 20 min |
| October | 83°F | 53°F | 68.2°F | 4.34 | 7 | 8 | <1 | 11 h 30 min |
| November | 72°F | 44°F | 58.3°F | 3.55 | 8 | <1 | 4 | 10 h 40 min |
| December | 64°F | 37°F | 50.6°F | 3.65 | 10 | <1 | 11 | 10 h 10 min |
| Year (annual) | 81°F | 53°F | 67.0°F | 40.95 | 94 | 125 | 37 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 17°C | 2°C | 9.2°C | 81 mm |
| February | 19°C | 4°C | 11.3°C | 74 mm |
| March | 23°C | 8°C | 15.1°C | 82 mm |
| April | 27°C | 12°C | 19.1°C | 85 mm |
| May | 31°C | 16°C | 23.4°C | 120 mm |
| June | 34°C | 20°C | 27.1°C | 100 mm |
| July | 36°C | 21°C | 28.6°C | 48 mm |
| August | 37°C | 21°C | 28.8°C | 71 mm |
| September | 33°C | 18°C | 25.6°C | 87 mm |
| October | 29°C | 12°C | 20.1°C | 110 mm |
| November | 22°C | 7°C | 14.6°C | 90 mm |
| December | 18°C | 3°C | 10.3°C | 93 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00418446; 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.
When is the best weather to visit Somerville?
Normal highs sit between 65°F and 85°F in February, March, April, October and November. Of those, April has the fewest days with rain (7).
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 USC00418446.
When is the last frost in Somerville?
In Somerville, the last spring frost (32°F) comes after March 18 in half of years and after April 6 in one year in ten; the first autumn frost comes before November 9 in half of years and before October 26 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
- March 181 year in 10 after April 6; 9 in 10 after February 25
- First autumn frost, half of years before
- November 91 year in 10 before October 26; 9 in 10 before November 30
NOAA puts the median frost-free season at 238 days, and the season without a hard freeze (28°F) at 263 days.
A hard freeze (28°F) comes after March 5 in half of springs and before November 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Somerville in zone 9a in ZIP code 77863, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Somerville's NOAA station is in zone 8b: the coldest night of a typical year reaches 18°F (18 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Texas · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00418446; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 in Somerville?
In a normal year in Somerville, 125 days a year reach 90°F (27 of them 100°F or more), 37 nights fall to 32°F or colder and 94 days bring measurable precipitation.
- Days at 90°F or more
- 125a normal year
- Days at 100°F or more
- 27a normal year
- Nights at 32°F or colder
- 37a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 94a normal year
The highest temperature in this station's record (since 1963) is 114°F, on September 5, 2000; the lowest is 3°F, on December 23, 1989.
The wettest calendar year on that record is 1968, with 66.57 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00418446; records: ACIS (NOAA Regional Climate Centers), station USC00418446. Records use complete months only; a month missing more than three days is left out.
How sunny is Somerville?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Somerville, 4.7 kWh per square metre a day. August is the sunniest month (87%) and February the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 2.9 |
| February | 66% | 3.4 |
| March | 71% | 4.5 |
| April | 75% | 5.4 |
| May | 77% | 5.9 |
| June | 84% | 6.6 |
| July | 86% | 6.6 |
| August | 87% | 6.2 |
| September | 82% | 5.2 |
| October | 81% | 4.3 |
| November | 76% | 3.2 |
| December | 71% | 2.6 |
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 much heating and cooling does Somerville need?
A normal year in Somerville brings 1,933 heating degree days, 64% fewer than the median U.S. place (5,373), and 2,690 cooling degree days, 3.0 times the median (908). Three months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 6,621 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 514 | 4 |
| February | 360 | 7 |
| March | 218 | 38 |
| April | 70 | 108 |
| May | 8 | 293 |
| June | 0 | 473 |
| July | 0 | 574 |
| August | 0 | 586 |
| September | 4 | 397 |
| October | 63 | 164 |
| November | 241 | 39 |
| December | 456 | 9 |
| Year (annual) | 1,933 | 2,690 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00418446. 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.
Has Somerville been warmer than normal lately?
Over 33 complete years from 1968 to 2015, the station's annual mean temperature rose at a fitted -0.1°F per century (−0.00°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Somerville's climate compare?
Somerville is warmer than 203 of the other 320 places with their own NOAA record in Texas, and wetter than 236. Across the 7,247 U.S. stations with normals, its annual mean of 67.0°F is warmer than 92%.
In the Köppen classification computed from these normals, Somerville 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 Somerville share this climate record?
6 places have no NOAA station with 1991-2020 normals of their 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.
- Caldwell, TX4,820 people · 16 mi NW
- Beaver Creek, TX923 people · 8 mi N
- Lyons, TX454 people · 5 mi N
- Burton, TX286 people · 11 mi S
- Carmine, TX252 people · 16 mi SW
- Deanville, TX18 people · 14 mi NW
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 Somerville's climate
What is the coldest month in Somerville?
January, with a normal high of 62°F and a normal low of 35°F. The warmest is August (98°F by day, 70°F at night).
Does it snow in Somerville?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in Somerville?
May, with 4.73 in of precipitation in a normal year; the driest is July with 1.88 in.
What plant hardiness zone is Somerville in?
The USDA's 2023 map puts Somerville in zone 9a in ZIP code 77863, the nearest ZIP area. By the same method at Somerville's NOAA station, the coldest night of a typical year reaches 18°F (18 years, 1991-2020): zone 8b.
How late can frost come in Somerville?
In half of years the last 32°F night comes after March 18; in one year in ten it comes after April 6. Waiting until April 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Texas climateThe statewide normals and every place in the state
- Brenham, TX15 miles from this station, 68.0°F a year
- College Station, TX21 miles from this station, 69.4°F a year
- Washington State Park, TX23 miles from this station, 68.0°F a year
- Bellville, TX29 miles from this station, 68.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made