Climate Comfort Score
97/100
Excellent
NOAA 1991–2020 normals 69°F annual avg Public-domain federal data
San Marcos, TX Climate
Temperature, precipitation, and comfort score from NOAA NCEI 1991–2020 normals →
- 69°F
- Avg annual temp
- 97/100
- Comfort score
- 36.5"
- Annual precip
- 274d
- Growing season
30-year climate normals from 1 weather station (1991-2020).
The climate verdict for San Marcos
San Marcos, Texas averages 69°F a year and scores 97/100 on the comfort index - excellent, milder than 98% of U.S. cities.
- 69°F
- annual average temperature (NOAA normal)
- 97/100
- comfort score, milder than 98% of U.S. cities
- 36.5"
- precipitation, annual total
- 274 days
- frost-free days per growing season
Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.
Avg Temperature
69°F (20°C)
Avg High
80°F
Avg Low
57°F
Annual Precip
36.5"
Annual Snow
0.0"
Comfort Score
97/100
Excellent
Avg Annual Temperature
69°F
30-year mean (NOAA NCEI)
Annual Precipitation
36.5"
Liquid-equivalent total
Comfort score vs national 100-point ceiling (San Marcos) 97.0%
National median (63)
PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Excellent for the San Marcos area.
How San Marcos compares to every U.S. city
San Marcos's comfort score vs. all U.S. cities
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
97 Top 2% higher than 98% of 6,915 US cities
Each bar is a band; taller bars hold more US cities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Warming context for San Marcos
MethodologyZooming out from San Marcos's own normal, the chart below shows how the U.S. land temperature anomaly has tracked the global mean since 1900 - the most recent decade sits warmer than the 30-year mean shown here.
- United States land mean (NOAA NCEI) +0.11 °C/decade
- Global anomaly (NASA GISTEMP) +0.11 °C/decade
- Paris Agreement thresholds 1.5°C / 2.0°C
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 62°F (17°C) | 39°F (4°C) | 51°F (10°C) | 2.4" | 0.0" | 6.9 | 0.0 |
| February | 67°F (19°C) | 42°F (6°C) | 55°F (13°C) | 1.7" | 0.0" | 4.4 | 0.2 |
| March | 73°F (23°C) | 50°F (10°C) | 61°F (16°C) | 2.8" | 0.0" | 1.2 | 0.3 |
| April | 80°F (27°C) | 56°F (13°C) | 68°F (20°C) | 3.2" | 0.0" | 0.0 | 1.8 |
| May | 86°F (30°C) | 65°F (18°C) | 76°F (24°C) | 4.5" | 0.0" | 0.0 | 9.7 |
| June | 92°F (34°C) | 72°F (22°C) | 82°F (28°C) | 3.6" | 0.0" | 0.0 | 23.6 |
| July | 96°F (35°C) | 73°F (23°C) | 85°F (29°C) | 2.2" | 0.0" | 0.0 | 28.5 |
| August | 97°F (36°C) | 74°F (23°C) | 85°F (30°C) | 2.6" | 0.0" | 0.0 | 28.6 |
| September | 91°F (33°C) | 69°F (20°C) | 80°F (26°C) | 4.0" | 0.0" | 0.0 | 19.1 |
| October | 82°F (28°C) | 58°F (15°C) | 70°F (21°C) | 4.4" | 0.0" | 0.0 | 4.9 |
| November | 72°F (22°C) | 48°F (9°C) | 60°F (16°C) | 2.7" | 0.0" | 1.7 | 0.0 |
| December | 64°F (18°C) | 41°F (5°C) | 52°F (11°C) | 2.4" | 0.0" | 5.6 | 0.0 |
Monthly Precipitation
Average monthly rainfall and snowfall
January 2.4"
7.1 days with precipitation
February 1.7"
7.4 days with precipitation
March 2.8"
8.1 days with precipitation
April 3.2"
6.5 days with precipitation
May 4.5"
8.0 days with precipitation
June 3.6"
6.3 days with precipitation
July 2.2"
5.2 days with precipitation
August 2.6"
4.8 days with precipitation
September 4.0"
7.2 days with precipitation
October 4.4"
6.0 days with precipitation
November 2.7"
6.1 days with precipitation
December 2.4"
7.6 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
November 29
50% probability date
Last Spring Freeze
February 28
50% probability date
Growing Season
274 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
1,620
Higher = more heating needed
Cooling Degree Days
2,974
Higher = more cooling needed
Warmest Month
August
Coldest Month
January
What San Marcos's climate means for you
San Marcos runs 69°F a year - peaking in August, coldest in January.
- Gardeners get about 274 frost-free days, with the last spring freeze near February 28 - plan the planting calendar around it, not the regional average.
- Energy bills track 1,620 heating and 2,974 cooling degree days a year, higher means the furnace or AC runs more.
- Comparing places to live? Line this city up against nearby cities and the national rankings. See rankings
These are 30-year NOAA normals (1991–2020) - the typical year, not a forecast for any specific season.
Climate Guides
Climate Insight: San Marcos, TX
San Marcos, Texas runs an annual average of 69°F, ranging from a mean daily high of 80°F to a mean daily low of 57°F, per NOAA's 1991–2020 climate normals. August is typically the warmest month of the year, while January is the coldest. Drawn from station USC00417983, these thirty-year averages smooth out year-to-year swings into a baseline for what a typical month looks like here.
Beyond temperature, San Marcos averages 36.5 inches of precipitation annually, with negligible snowfall - a real factor for anyone planning to live, garden, or travel here. The frost-free season averages 274 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near February 28 and the first fall freeze near November 29. Turning to energy use, 1,620 heating degree days and 2,974 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, San Marcos scores 97/100 (Excellent), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. For planning purposes, look to the monthly tables above: shoulder seasons bring the mildest highs and lows, summer brings August-driven heat, and deep winter brings January-driven cold. Treat every figure here as a thirty-year average rather than a forecast - individual years routinely run warmer, cooler, wetter, or drier than the normal.
Frequently Asked Questions
What is the average temperature in San Marcos, TX? ▼
The average annual temperature in San Marcos, Texas is 69°F. The warmest month averages 97°F (36°C) and the coldest averages 39°F (4°C).
How much rain does San Marcos get? ▼
San Marcos receives 36.5 inches of precipitation annually. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for San Marcos? ▼
San Marcos has a climate comfort score of 97/100 (Excellent), milder than 98% of U.S. cities in the PlainClimate database.
When is the growing season in San Marcos? ▼
San Marcos has approximately 274 frost-free days per year, with the last spring freeze around February 28 and the first fall freeze around November 29.
How much energy does heating and cooling require in San Marcos? ▼
San Marcos has 1,620 heating degree days and 2,974 cooling degree days annually, a fairly balanced heating/cooling split. See our <a href="/guides/reading-weather-data/" class="underline hover:text-brand-600">guide to reading weather data</a> for what these figures mean.
Where does this San Marcos climate data come from? ▼
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USC00417983 near San Marcos.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USC00417983. For informational purposes only.
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial
Every figure on PlainClimate is rendered directly from NOAA 1991-2020 U.S. Climate Normals data, no number is typed in by an editor. This page draws directly on NOAA 1991-2020 U.S. Climate Normals data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.