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San Marcos city, TX

ZIP 78666 — Climate & Environment

Source: U.S. Census Bureau ACS 2019–2023 5-Year Estimates. Page data updated 2026-08-02.

Working ClassLarge CommunityLow Snow Area

Climate, disaster risk, air quality, and environmental safety

Environment & Risk in ZIP Code 78666

Disaster Risk (FEMA NRI)

County-linked natural hazard risk from FEMA National Risk Index — useful for comparing insurance and disaster exposure.

FEMA’s National Risk Index rates natural-hazard risk for San Marcos city, TX as Relatively Moderate (composite score 90.6), which is among the highest nationally. The strongest component scores on US5 are flood (93.2) and wildfire (87.9). These scores are county-linked NRI values published for planning context — all ZIP codes in the same county share the same composite score on US5. Useful when comparing insurance and disaster exposure across areas, not a substitute for a parcel-level flood or fire determination.

Overall rating
Relatively Moderate
Risk index
90.6
Flood risk
93.2
Wildfire risk
87.9
Hurricane risk
63.9
Earthquake risk
25.8
Tornado risk
96.1
Winter weather risk
93.8
Hail risk
96.8

Climate & Weather in ZIP Code 78666

Climate normals for San Marcos city, TX show little to no average snow and around 36.5 inches of annual precipitation. Pair that with FEMA NRI hazard context (overall rating Relatively Moderate) when evaluating long-term housing and insurance exposure.

7-day weather forecast

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Sunrise, sunset & moon

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Monthly Temperature

30-year climate normals (avg. monthly temperature)

Climate Data
Hardiness Zone
9a
Annual Snow Days
0
Annual Precipitation
36.55 in
FEMA NRI rating
Relatively Moderate

Climate & Environment key statistics

Climate statistics
Climate
Hardiness zone9a
Annual precip (in)36.55
Snow days0
Broadband access85.0%
Risk & Air Quality statistics
Risk & Air Quality
NRI ratingRelatively Moderate
NRI risk index90.6
Flood risk (NRI)93.2
Wildfire risk (NRI)87.9
Hurricane risk (NRI)63.9
IRS net migration4140