Weather risk for filming in San Jose
San Jose averages 11 rain days in March — a three-day exterior shoot then hits at least one with 75 % probability. In June (0 rain days) the same risk drops to 0 %. The calculator above is preset to San Jose and runs the numbers for your count of exterior days.
Weather risk calculator for San Jose
- Risk per day
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- At least one day hit
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- Expected lost days
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Rain risk in San Jose by month
Rain days are long-term monthly means — not a forecast, but the basis for the budget question: once the chance of losing a day passes ~60 %, the cover set is cheaper than the loss.
| Month | Rain days | Mean temp | Sun hours/day | Risk (3 days) |
|---|---|---|---|---|
| January | 10 | 10.7 °C | 7.2 | 70 % |
| February | 7 | 11.4 °C | 8.9 | 55 % |
| March | 11 | 12.5 °C | 9.4 | 75 % |
| April | 4 | 14.4 °C | 11.3 | 35 % |
| May | 3 | 16.6 °C | 12.8 | 27 % |
| June | 0 | 20.1 °C | 13.7 | 0 % |
| July | 1 | 20.9 °C | 13.8 | 10 % |
| August | 0 | 21.1 °C | 12.9 | 0 % |
| September | 1 | 20.8 °C | 11.7 | 10 % |
| October | 3 | 18.4 °C | 10.3 | 27 % |
| November | 6 | 13.3 °C | 8.7 | 49 % |
| December | 10 | 10.4 °C | 7.3 | 70 % |
The best month for exteriors
Combining daylight and rain days, June comes out ahead in San Jose: 14h 43min of usable light against 0 mean rain days. The driest month (June) and the brightest are not automatically the same — which is exactly why the combined view matters.
For scheduling, a weather day costs more than the day itself: location availability, crew follow-on bookings and possibly the travel home. TillyGen puts the month's rain risk right next to the sun window inside the schedule — together they decide which day can happen outside.
Frequently asked
When does it rain least in San Jose?
June, with a mean of 0 rain days. The most falls in March with 11.
How is the washout risk computed?
Rain days ÷ 30 gives the per-day hit probability; across N exterior days, 1 − (1 − p)ᴺ is the chance of at least one hit. Deliberately simple and conservative — it prices the month's structural risk rather than forecasting weather.
What is the best month to shoot in San Jose?
On light and rain combined, June. The matching sun times live on the golden-hour page for San Jose and on the city page.