ERA5 almanac comparison — 8 years of real data
Marfa vs San Diego: weather in July
San Diego edges out Marfa for sun in July: 88% clear historically versus 61% (8-year ERA5 average, a 27-point gap). Marfa also sees measurably more rain than San Diego this month (16% vs 1% of days). Both are viable — San Diego is the safer bet.
What you are reading: 8-year historical averages, not a forecast.
Either destination can still surprise you this specific July. For this
week’s actual forecast, each destination links to its live page below.
Marfa
TX
- Clear days, July
- 61%
- Sample size
- n=248 days
- Avg high
- 91°F
- Early July (1st–15th)
- 52%
- Late July (16th–end)
- 69%
- Rain frequency
- 16% of days
San Diego
CA
- Clear days, July
- 88%
- Sample size
- n=248 days
- Avg high
- 76°F
- Early July (1st–15th)
- 82%
- Late July (16th–end)
- 94%
- Rain frequency
- 1% of days
Compare Marfa vs San Diego in another month
All percentages are historical averages from the ERA5 reanalysis via Open-Meteo, 8 full years (2018–2025). “Clear” means avg high ≥ 72 °F, precipitation < 1 mm, and a non-precipitation weather code. This is history, not a forecast. The live 7-day outlook for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.