WorkWindow

Driveway Sealing Weather in San Francisco, CA: 10-Day Windows & Best Months

The driveway sealing season in San Francisco runs May through November — 7 months averaging at least 8 workable days by NOAA 1991–2020 normals. August leads the calendar with 30 workable days: average high 68°F, low 56°F, rain on 3% of days. Below: today through day 10 against the label rules, then the year at a glance.

GOOD — every label check passes MARGINAL — one soft fail NO — hard fail or several soft

The rules this check uses

The San Francisco verdicts run on these rows — consensus pail numbers with one editorial call: 36 cure hours, the honest middle of the 24–48 range labels print.

Typical label thresholds for driveway sealing — the ruleset behind every San Francisco verdict above.
CheckThresholdWhy it matters
Air temperature 55–90°F, and rising The film (or mix) chemistry runs on temperature — both while you work and for the first hours after.
Overnight low ≥50°F during the first 24 h Curing continues after dark; the first night can undo a perfect afternoon.
Dry before ≤0.05" rain in the prior 24 h Checked backward from your start hour using the two look-back days in the forecast data.
Dry after <0.05" rain for 36 h after (48 h cool or shaded driveways want 48 h) The engine sums forecast rain hour by hour through the cure window for San Francisco.
Evening dew-point spread ≥5°F from 6–11 pm When air temperature meets the dew point, water condenses on your fresh work first.
Daytime humidity ≤85% Read as the daytime maximum, 10 a.m.–5 p.m.; within 3 points of the limit counts as marginal.
Wind ≤20 mph (dust and debris in wet sealer up to 28 mph) Strong wind drops leaves and grit into the wet coat.

Always follow your product label — formulas vary. The table above is the typical range across major manufacturers, not a promise about your can.

Best months for driveway sealing in San Francisco

San Francisco's calendar, scored: each month's days passing the temperature rules, discounted by that day's historical rain odds (NOAA 1991–2020). Not a forecast.
MonthAvg highAvg lowRain odds/dayWorkable days 
January 58°F 47°F 36% 0
February 60°F 48°F 38% 0
March 62°F 49°F 34% 0
April 63°F 50°F 23% 7
May 64°F 51°F 13% 27
June 66°F 53°F 6% 28
July 66°F 54°F 3% 30
August 68°F 56°F 3% 30
September 70°F 56°F 4% 29
October 70°F 54°F 12% 27
November 64°F 51°F 26% 15
December 58°F 47°F 36% 0

The working season runs May through November — about 193 workable days a year. The edges are night-limited: label rules want overnight lows of 50°F+, and San Francisco's nights only average that from May to November. The California table ranks every listed city by the same math.

San Francisco has a real wet/dry rhythm: February brings rain on 38% of days versus 3% in August. When the calendar gives you a August-side window, the dry-before and dry-after rules nearly take care of themselves.

The other driveway job reads differently: pouring concrete in San Francisco cares about two safe nights, not rising afternoons.

Source honesty: every monthly figure on this page is the 1991–2020 normal at San Francisco Dwtn, Ca Us, 2.3 km from San Francisco's center — your block's shade lines and wind exposure sit on top of that baseline. Scoring details are on the methodology page.

San Francisco by the numbers

Prep checklist

  1. The strip above is hunting one shape: 55°F rising, a 50°F+ night, 36 dry hours. San Francisco produces it 30 days in a typical August.
  2. Day-before job: crack filler in every crack, so it cures before the sealcoat lands.
  3. Hit oil spots with degreaser and sweep hard; sealer over dust peels in playing-card flakes.
  4. Confirm the lookback: under 0.05" of rain in the prior 24 h — after a February shower (38% of days), cracks hold water longest.
  5. Tape the garage slab and sidewalk lines with edging tape — drips on concrete are forever.
  6. Pull thin passes with a squeegee/brush combo, back-brushing the texture as you go.
  7. Morning start at the garage end, working toward the street — San Francisco's August gives the coat 68°F daylight before the evening spread tightens.
  8. Keep tires off through the full cure — with August nights at 56°F, shaded strips need the long end of 24–48 h.

Gear that saves a window

Transparency note: gear links here become affiliate links only when the program is enabled — today they are plain references. See the affiliate disclosure.

FAQ

What temperature do you need to seal a driveway?

The pail wants 55°F+ air, a 50°F+ first night, and temperatures trending up through the cure. San Francisco clears all three reliably from May through November; outside that, January's 47°F average nights end the argument.

How long after rain can I sealcoat?

Give it a full dry day: the engine fails any start within 24 hours of measurable rain. Filled cracks dry last. San Francisco's rain-day odds run 3–38% across the year, so the same rule costs different months very differently.

How long does driveway sealer take to dry before rain or cars?

Labels say 24–48 hours; this site checks 36 as the honest middle. Foot traffic sooner, tires last. San Francisco's cure risk is mostly rain timing — in February, odds of a wet day inside a 36-hour window run high enough that the strip above is the only sane scheduler.

Can you seal a driveway in the fall?

In San Francisco, early fall works while nights hold: the season's last reliable month is November (average low 51°F against the 50°F first-night rule). After that, warm afternoons sit on cold slabs and the cure stalls.

How often should a driveway be sealed?

Every 2–4 years, or when water stops beading and the surface grays. More often builds a peeling film; less often lets water work the cracks. New asphalt cures 6–12 months before its first coat — and crack filler goes in a day ahead.

Best month to seal a driveway in CA?

August tops San Francisco's table at 30 days clearing the 55–90°F-rising, 50°F-night, 36-dry-hour stack; August and July together carry the season. Check the CA state page for how the ranking shifts across the state.

Other projects in San Francisco

Driveway Sealing nearby

Guides

Climatology: NOAA 1991–2020 normals via SAN FRANCISCO DWTN, CA US (2.3 km from San Francisco center, elevation 150 ft); live outlook by Open-Meteo.