July 20 in San Antonio
Weather forecasts run out after about two weeks. For any date further out than that, the honest answer isn't a single number — it's the range San Antonio actually delivers on this date, and how often.
On July 20, San Antonio, TX typically reaches 98°F, but has run anywhere from 90°F to 103°F in eight years out of ten. About 85% of July 20s see no measurable precipitation.
The odds on July 20
Odds computed from the last 30 years (1997–2026).
Where this comes from: 146 daily observations from SAN ANTONIO KELLY AFB, covering 1970–2026. We pool every day within 7 days of July 20 — a single calendar date has only about 56 readings, far too few to place a 10th percentile you'd want to trust.
Why it's not a plain average: A climatology computed straight across 1970–2026 describes the middle of that period, not today, so as a statement about the present it runs cold. We fit a trend on year and shift each observation to 2026 before taking the range. The probabilities use the last 30 years instead — shifting a temperature along a trend is well defined, shifting “did it rain” is not.
What this is not: Not a forecast. It is what San Antonio, TX has actually done on this date, which is the only defensible answer once you're past the two-week horizon where real forecasts stop. Data: NOAA NCEI GHCN-Daily.