Rain in Los Angeles comes in a short season. A replacement strips the covering off, and for a day or two the house depends on temporary protection. Choosing the start date with the season in mind keeps that window small.
The rain calendar in numbers
The National Weather Service normals for Downtown Los Angeles, 1991-2020, give the shape of the year. October is light at 0.58 inches. November adds 0.78 and December jumps to 2.48. January brings 3.29 and February peaks at 3.64 (National Weather Service, 1991-2020 normals).
March eases to 2.23, April to 0.69 and May to 0.32. June gives 0.09, July 0.02, August none and September 0.13. The year totals about 14.25 inches.
Five months, November through March, bring about 12.42 of those inches, roughly 87 percent. The summer is close to dry.
What a tear-off exposes
Once the old covering is stripped, the deck is bare. Underlayment goes down as the work moves, and anything left open at day's end is dried in. That routine works well in dry weather.
In wet weather the margin shrinks. Water on a bare deck soaks boards that may be reused, and a forecast that changes mid-job can leave a slope open longer than planned. A tear-off in the dry months leaves less to protect.
The forecast is read before work starts, and only what can be closed by evening is stripped.
What happens to the calendar after storms
Storms change how fast roofers can start. In November 2015, ABC7 told how roofers in Los Angeles filled their books as homeowners hurried to beat the forecast El Nino rains (ABC7, 7 Nov 2015). FOX 11 reported in 2023 that after the historic storms of early that year, people had trouble getting a roofer to return their calls (FOX 11, 2 Mar 2023).
The lesson is not to wait for the first storm.
Rain and the covering you choose
Each covering answers rain in its own way. Tile sheds water over a layered system and relies on the underlayment beneath. Shingles shed water in overlapping courses. Metal sheds it too, and on a solid deck with good underlayment it sounds softer in rain.
A flat roof needs a plan for drainage. Crickets and scuppers move the water off. None of these answers is a reason to delay a roof that is already failing. It is a reason to pick the start date with care.
A calendar you can use
Late spring through early autumn is the quiet stretch: June to September sits near zero in the normals. A request made in April or May can be scoped, permitted and started in that window.
If the roof is leaking now, do not wait for a perfect month. Tell us what is going on and we plan the safest order of work. If it is not leaking, use the dry months and spare yourself the rush.
Rain and roofing questions
What goes wrong when a tear-off meets rain?
A bare deck absorbs water, and boards that were reusable can go soft. A forecast that shifts mid-job can leave a slope open longer than planned. We close each section by the end of the day and check the forecast first.
Does rain sound louder on a metal roof?
Over a solid deck with proper underlayment, rain on metal sounds softer. A thin or bare deck makes more noise. Ask which deck and underlayment the scope uses.
How do roofer schedules shift once the storms start?
Both news items (ABC7, 7 Nov 2015; FOX 11, 2 Mar 2023) describe the same crunch: homeowners racing the weather and roofers booked up.