Last frost date in San Marcos, TX
The average last frost in San Marcos is February 28. By March 21 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about November 29, which leaves 273 frost-free days. An early freeze before November 8 happens one year in ten.
- Safe after (10% risk)
- Mar 21
- Average first frost
- Nov 29
- Frost-free season
- 273 days
- Hard freeze (28°F) ends
- Feb 13
No frost in the next 7 nights
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2258°
- FriOct 2359°
- SatOct 2461°
- SunOct 2559°
- MonOct 2662°
- TueOct 2758°
- WedOct 2858°
Planting calendar for San Marcos
Windows count forward or back from the average frost dates above. Click a crop for dates across Texas.
TomatoesMar 7–Mar 21
PumpkinsMar 14–Mar 28
SunflowersFeb 28–Mar 21
CucumbersMar 14–Mar 21
CornMar 7–Mar 21
Sweet potatoesMar 21–Apr 4
WatermelonMar 14–Mar 28
Green beansMar 7–Mar 28
ZucchiniMar 7–Mar 21
OkraMar 21–Apr 4
PeppersMar 14–Mar 28
BasilMar 7–Mar 21
Butternut squashMar 7–Mar 21
CantaloupeMar 14–Mar 28
EggplantMar 14–Mar 28
PotatoesJan 31–Feb 14
OnionsJan 17–Feb 7
CarrotsFeb 7–Mar 14
LettuceFeb 14–Mar 7
BroccoliJan 31–Feb 14
BeetsJan 31–Mar 14
PeasJan 17–Jan 31
CabbageJan 31–Feb 14
RadishesJan 24–Mar 7
Brussels sproutsFeb 14–Feb 28
SpinachJan 17–Feb 7
CilantroFeb 14–Mar 7
KaleJan 31–Feb 14
Collard greensJan 31–Feb 14
TurnipsJan 31–Feb 14
DillFeb 28–Mar 14
CeleryMar 7–Mar 14
CauliflowerFeb 14–Feb 28
LeeksFeb 14–Feb 28
Swiss chardFeb 14–Mar 14
ParsleyFeb 14–Mar 7
Tulip bulbsNov 15–Dec 15
GarlicOct 15–Nov 30
Daffodil bulbsOct 15–Nov 30
StrawberriesJan 31–Feb 14
AsparagusJan 31–Feb 14Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Feb 1 | Feb 28 | Mar 21 | Nov 8 | Nov 29 | Dec 21 |
| Hard freeze, 28°F | Jan 9 | Feb 13 | Mar 8 | Nov 19 | Dec 15 | Jan 13 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station San Marcos (USC00417983) sits 1.0 miles from the center of San Marcos at 665 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in San Marcos, TX?
The average last frost date in San Marcos is February 28, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after March 21.
When is the first frost in San Marcos?
The first frost in fall usually comes around November 29. One year in ten it arrives before November 8.
How long is the growing season in San Marcos?
About 273 days between the average last and first frost.
When should I plant tomatoes in San Marcos?
Plant tomato seedlings outside from March 7 to March 21. Start seeds indoors six to eight weeks earlier.
Nearby in Texas
- KyleFeb 28
- New BraunfelsMar 8
- Canyon LakeMar 1
- SeguinMar 1
- CiboloFeb 21
- SchertzFeb 21
- AustinFeb 20
- Universal CityFeb 21
- ConverseFeb 21
- Timberwood ParkFeb 26
- ManorMar 4
- PflugervilleMar 11