WorkWindow

Driveway Sealing Weather in Allentown, PA: 10-Day Windows & Best Months

The driveway sealing season in Allentown runs May through September — 5 months averaging at least 8 workable days by NOAA 1991–2020 normals. August leads the calendar with 21 workable days: average high 84°F, low 63°F, rain on 33% 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 Allentown 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 Allentown 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 Allentown.
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 Allentown

Allentown'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 38°F 22°F 37% 0
February 42°F 23°F 35% 0
March 51°F 30°F 36% 0
April 63°F 40°F 39% 0
May 74°F 51°F 40% 11
June 82°F 60°F 38% 19
July 86°F 65°F 35% 20
August 84°F 63°F 33% 21
September 77°F 55°F 32% 20
October 66°F 44°F 32% 0
November 54°F 34°F 31% 0
December 43°F 27°F 37% 0

The working season runs May through September — about 90 workable days a year. The edges are night-limited: label rules want overnight lows of 50°F+, and Allentown's nights only average that from May to September. The Pennsylvania table ranks every listed city by the same math.

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

Source honesty: every monthly figure on this page is the 1991–2020 normal at Allentown Intl Ap, Pa Us, 6.4 km from Allentown's center — your block's shade lines and wind exposure sit on top of that baseline. Scoring details are on the methodology page.

Allentown by the numbers

Prep checklist

  1. The strip above is hunting one shape: 55°F rising, a 50°F+ night, 36 dry hours. Allentown produces it 21 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 May shower (40% 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 — Allentown's August gives the coat 84°F daylight before the evening spread tightens.
  8. Keep tires off through the full cure — with August nights at 63°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. Allentown clears all three reliably from May through September; outside that, January's 22°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. Allentown's rain-day odds run 31–40% 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. Allentown's cure risk is mostly rain timing — in May, 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 Allentown, early fall works while nights hold: the season's last reliable month is September (average low 55°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 through Allentown's 31 sub-40°F January nights. 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 PA?

For Allentown: August and July — August leads with 21 workable days (high 84°F, rain on 33% of days, nights 63°F). Elsewhere in PA, the state page ranks every listed city by the same math.

Other projects in Allentown

Driveway Sealing nearby

Guides

Climatology: NOAA 1991–2020 normals via ALLENTOWN INTL AP, PA US (6.4 km from Allentown center, elevation 390 ft); live outlook by Open-Meteo.