Weather risk for filming in Boston
Boston averages 12 rain days in March — a three-day exterior shoot then hits at least one with 78 % probability. In November (8 rain days) the same risk drops to 61 %. The calculator above is preset to Boston and runs the numbers for your count of exterior days.
Weather risk calculator for Boston
- Risk per day
- —
- At least one day hit
- —
- Expected lost days
- —
Runs entirely in your browser — no sign-up, nothing transmitted.
Rain risk in Boston by month
The "risk (3 days)" column answers the question behind every weather contingency: how likely does a three-day exterior block lose at least one day? From roughly 60 % upward, a cover set stops being optional and belongs in the budget.
| Month | Rain days | Mean temp | Sun hours/day | Risk (3 days) |
|---|---|---|---|---|
| January | 10 | -1.1 °C | 6.0 | 70 % |
| February | 10 | -0.6 °C | 6.7 | 70 % |
| March | 12 | 2.8 °C | 7.9 | 78 % |
| April | 12 | 8.3 °C | 8.4 | 78 % |
| May | 11 | 14.6 °C | 10.1 | 75 % |
| June | 11 | 19.8 °C | 11.2 | 75 % |
| July | 12 | 23.6 °C | 11.4 | 78 % |
| August | 11 | 22.9 °C | 10.9 | 75 % |
| September | 9 | 18.9 °C | 8.9 | 66 % |
| October | 9 | 12.9 °C | 7.5 | 66 % |
| November | 8 | 6.5 °C | 6.6 | 61 % |
| December | 11 | 1.8 °C | 5.7 | 75 % |
The best month for exteriors
Combining daylight and rain days, June comes out ahead in Boston: 15h 16min of usable light against 11 mean rain days. The driest month (November) 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 Boston?
November, with a mean of 8 rain days. The most falls in March with 12.
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 Boston?
On light and rain combined, June. The matching sun times live on the golden-hour page for Boston and on the city page.