WeatherArchive / Compare cities / Houston vs San Diego
Houston vs San Diego weather: climate comparison
Houston is the warmer of the two, averaging 70°F (21°C) over the year against 63°F (17°C) in San Diego. Houston is wetter, with 54.0 in (1372 mm) of precipitation a year to San Diego's 11.7 in (298 mm). Below: every month side by side, from 30 years of ERA5 data (1996–2025).
- Mean temperature
- 21.3°C Houston
17.0°C San Diego - Annual precipitation
- 1372.4 mm Houston
298.4 mm San Diego - Rainy days a year
- 132 Houston
38 San Diego - Sunshine per day
- 9.3 h Houston
10.9 h San Diego
Month by month
| Month | Houston | San Diego |
|---|---|---|
| January | 16.9°C | 17.5°C |
| February | 18.8°C | 17.3°C |
| March | 22.2°C | 17.8°C |
| April | 25.7°C | 19.1°C |
| May | 29.4°C | 20.2°C |
| June | 32.0°C | 21.9°C |
| July | 32.9°C | 24.3°C |
| August | 33.5°C | 25.3°C |
| September | 31.0°C | 25.0°C |
| October | 27.1°C | 23.1°C |
| November | 21.8°C | 20.4°C |
| December | 18.1°C | 17.5°C |
Year at a glance
| Measure | Houston | San Diego |
|---|---|---|
| Mean annual temperature | 21.3°C | 17.0°C |
| Warmest month (avg high) | Aug · 33°C | Aug · 25°C |
| Coldest month (avg low) | Jan · 8°C | Jan · 9°C |
| Annual range (warmest high − coldest low) | 26°C | 17°C |
| Annual precipitation | 1372.4 mm | 298.4 mm |
| Rainy days per year | 132 | 38 |
| Wettest / driest month | Sep / Feb | Feb / Jun |
| Average sunshine per day | 9.3 h | 10.9 h |
In short: Houston is the warmest overall (21.3°C mean); Houston gets the most precipitation (1372.4 mm a year); San Diego is the sunniest (10.9 h a day on average); San Diego has the smallest swing between its warmest and coldest months.
Record high 1996–2025: Houston 41.7°C (2000-09-04), San Diego 36.6°C (2020-09-30). Record low: Houston -10.9°C (2021-02-16), San Diego 1.8°C (2007-01-15).
Source: Open-Meteo Historical Weather API (CC BY 4.0). Values are ERA5 reanalysis model data on a ~9–25 km grid, not readings from a weather station, so a single town’s thermometer can differ by a few degrees and local showers can be missed. Monthly means of daily ERA5 values, 1996–2025, for the grid cells nearest Houston (29.77, -95.33) and San Diego (32.72, -117.14).
Which months differ most?
The gap in average highs is widest in June, when Houston runs 18°F / 10°C warmer, and narrowest in December (1°F / 1°C apart). The biggest rainfall difference is in September: Houston gets 5.1 in (130 mm) more on average.
Add a third or fourth city, or swap in any other place, in the full comparison tool. For one city in depth, see the Houston climate and San Diego climate pages.
Compare Houston or San Diego with another city
Questions people ask
Is Houston warmer than San Diego?
Houston is warmer on average: its mean annual temperature is 70°F (21°C) against 63°F (17°C) in San Diego (ERA5, 1996–2025).
Which gets more rain, Houston or San Diego?
Houston, with about 54.0 in (1372 mm) of precipitation a year and 132 days with at least 1 mm, compared with 11.7 in (298 mm) and 38 days in San Diego.
Which is sunnier, Houston or San Diego?
San Diego averages more sunshine: 10.9 h a day against 9.3 h. Sunshine duration is modelled from cloud cover.
How reliable is this comparison?
Both cities use the same 30-year reanalysis, so differences are consistent. Absolute values describe a grid cell several kilometres wide and can differ by a degree or two from the airport station.