Weather StoryAlmanac, microseasons, and the day's weather story.

Allentown, Pennsylvania Weather

Night falls a minute earlier. Day 43 of summer. Read this microseason across nine climate regions →

Allentown weather forecast — hour by hour, 7-day outlook, NOAA radar

Allentown, PA
Sunday, August 2 at 10:59 AM
81
°
Clear
Feels like
87°
Humidity
66%
Wind
8 mph
Sunrise
2:00 AM
Sunset
4:16 PM
Allentown, PA
Hour by hour · 24h
24-Hour ForecastAllentown, PA: 24-hour forecast. Temperatures range from 75 to 83 degrees Fahrenheit with a 51% chance of precipitation at 4 AM.
L 75°H 83°
Allentown, PA
7-day forecast
  1. Today
    Aug 2
    Showers
    49%
    0.10″
    83°73°—
  2. Monday
    Aug 3
    Showers
    51%
    0.21″
    86°72°+3°
  3. Tuesday
    Aug 4
    Overcast
    —
    —
    83°65°-3°
  4. Wednesday
    Aug 5
    Thunderstorm
    44%
    0.03″
    83°66°0°
  5. Thursday
    Aug 6
    Thunderstorm
    51%
    —
    88°72°+5°
  6. Friday
    Aug 7
    Thunderstorm
    52%
    0.01″
    94°72°+6°
  7. Saturday
    Aug 8
    Drizzle
    43%
    —
    91°70°-3°
Allentown, PA
Next 24 hours · Mild now
72°79°86°12p6p12a6anow 79°high 83°low 75°PRECIP %
Allentown, PA
Anemometer · 24h winds · from true
NESW
From · True
SE
144° · veering 32°
Direction
SE
144°
Sustained
8
mph
Gust
17
mph
Peak 24h
19
avg 5 mph
Beaufort · 3 · GENTLE BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 5 mph · pk 19 mph @ 7:00a
0102030MPHB1B2B3B4B5B6-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 247SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 32° from the se.
Allentown, PA
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
1004.0
+0.6 mb in 3h · rising · 29.65 inHg
Now
1004.0
mb
3h
+0.6
mb
12h
+0.8
mb
24h
-0.4
mb
Regime · RAIN
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 1003–1006
9951000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW1005.51003.01004.7
Damp, unsettled regime — wet weather lingers nearby.
Allentown, PA
Air quality
51
AQI
Moderate
→-3 in 6h

AQI 51 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 8.7 µg/m³, PM10 at 11.4 µg/m³ — typical background levels with no transport signature.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.

PM 2.5DRIVERGood
8.7μg/m³
PM 10Good
11μg/m³
NO₂Good
4μg/m³
OzoneModerate
87μg/m³
UV IndexModerate
2.6

What's driving it

Ozone × UV × Sky

Ozone at AQI 41. Overcast through the UV peak window (cloud cover ~93%) — afternoon ozone should stay flat.

Present
AQI 41
UV peak
3.7 at 1 PM
Sky at peak
overcast
Projected peak
AQI 10

PM × Wind × Precip

PM2.5 at 8.7 µg/m³, PM10 at 11.4 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.76
Wind
light
Recent rain
0h in last 6h
Pattern
background

Trends

Seven days of AQI and PM2.5.

Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).

7-DAY AQI TREND50100SUNMONTUEWEDTHUFRISATSUN7-DAY PM2.5 TREND · μg/m³370
Allentown, PA
Sky cover · visibility · 24h
Cloud cover
6%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
56.1mi
UNLIMITED
72 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
14:59 UTC · Allentown, PA · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
14:59 UTC · Allentown, PA · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Allentown, PA
Satellite · infrared · animated
Allentown, PA
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Allentown, PA
Almanac · Sunday, August 2
Red sky at night, sailor's delight.
Civil dawn
5:30 AM
Sunrise
2:00 AM
Daylight
14h 16m
Sunset
4:16 PM
Civil dusk
8:48 PM
Planting note
Sow fall peas. Start kale and collard seedlings for fall.
Allentown, PA
The moon
Waning Gibbous
84% illuminated
Moonrise
9:45 PM
Moonset
10:04 AM
In sign
♓︎ Pisces
Allentown, PA
Microseason
Aug 1–5

Night falls a minute earlier

celestial
Jan 159% of the yearDec 31

Read this microseason across nine climate regions →

Allentown at a glance

  • Today vs. normal: 19°F above the seasonal normal for this latitude
  • Last frost: April 20 (climatological average for this latitude)
  • Microseason: Aug 1–5
  • Planting window: Sow fall peas. Start kale and collard seedlings for fall.

ZIP codes: 18101, 18102, 18103, 18104, 18106, 18109, 18195

16-Day Forecast — Allentown

  1. Sun83°73°50%
  2. Mon86°72°52%
  3. Tue83°65°5%
  4. Wed83°66°39%
  5. Thu88°72°62%
  6. Fri94°72°50%
  7. Sat91°70°52%
  8. Sun94°72°29%
  9. Mon95°75°25%
  10. Tue86°70°18%
  11. Wed84°64°19%
  12. Thu86°68°39%
  13. Fri93°73°45%
  14. Sat90°74°35%
  15. Sun93°73°30%
  16. Mon90°71°23%

Forecast data from Open-Meteo (CC BY 4.0).

Live wind & temperature near Allentown

Right now in the garden

Peak growing season

As of August 2, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

SPC Convective Outlook

Storm Prediction Center — Allentown

SPC has placed Allentown in the Marginal Risk category for severe thunderstorms today.

  • TODAYMRGLMarginal Risk
  • TOMORROWMRGLMarginal Risk
  • DAY 3TSTMGeneral Thunderstorms

Isolated severe storms possible. Limited threat for hail or damaging wind.

Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.

Sun & seasons in Allentown

Allentown sits in Lehigh County, where the year’s longest day runs 15h 5m of daylight and its shortest just 9h 16m — a swing of +5h 49m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.

Philadelphia, the state’s largest city, lies about 44 miles to the SSE. The nearest town Allentown tracks is Trumbauersville, roughly 14 miles to the SSE.

Air quality in Allentown’s county has trended cleaner since 2020; its cleanest year on record was 2024 (median AQI 39). See the full air-quality history for Allentown.

January 1–5: The year turns in silence.January 6–10: Ice thickens on still water.January 11–15: Shortest shadows lengthen.January 16–20: Pheasants begin to call.January 21–25: Springs begin to thaw.January 26–31: Chickadees announce dawn.February 1–5: East wind softens the frost.February 6–10: Sap begins to rise.February 11–15: First snowdrops appear.February 16–20: Red-winged blackbirds return.February 21–25: Rain begins to replace snow.February 26–28: Skunk cabbage pushes through ice.March 1–5: Ice withdraws from the reservoir.March 6–10: Crocuses open to weak sun.March 11–15: Peepers call from the marsh.March 16–20: Woodcocks spiral at dusk.March 21–25: Equinox — light overtakes dark.March 26–31: Forsythia opens along the fences.April 1–5: Cherry blossoms drift like snow.April 6–10: Warblers appear in the understory.April 11–15: Magnolias bloom and fall in a day.April 16–20: Dogwoods float above the forest.April 21–25: Lilacs perfume the evening.April 26–30: Last frost releases the garden.May 1–5: Warblers flood the Ramble.May 6–10: Tulip poplars light their candles.May 11–15: Shad run up the rivers.May 16–20: Roses open along the stoops.May 21–25: Firefly scouts appear at dusk.May 26–31: Strawberries ripen in the sun.June 1–5: Fireflies rise from the lawn.June 6–10: Elderflowers open in hedgerows.June 11–15: Solstice approaches — longest light.June 16–20: Honeysuckle sweetens the night.June 21–25: Solstice — the sun stands still.June 26–30: Lightning bugs drift through oaks.July 1–5: Cicadas claim the afternoon.July 6–10: Queen Anne's lace lines the roads.July 11–15: Thunder builds each afternoon.July 16–20: Corn reaches for the tassels.July 21–25: Dog days settle in the haze.July 26–31: Katydids begin their chorus.August 1–5: Night falls a minute earlier.August 6–10: Sunflowers face the morning.August 11–15: Goldenrod begins to bloom.August 16–20: Crickets pulse through warm nights.August 21–25: First cool morning surprises.August 26–31: Monarchs stage for flight.September 1–5: School buses reappear.September 6–10: Asters purple the roadsides.September 11–15: Hawk migration over the Hudson.September 16–20: Equinox — dark overtakes light.September 21–25: Apples hang heavy on the branch.September 26–30: Geese begin to chevron south.October 1–5: Witch hazel blooms as others fade.October 6–10: Maples begin to blaze.October 11–15: Frost paints the garden black.October 16–20: Oaks turn bronze and russet.October 21–25: Leaves rattle down the gutters.October 26–31: Clocks fall back — dusk at five.November 1–5: Ginkgos drop overnight.November 6–10: Last leaves cling stubbornly.November 11–15: Juncos arrive from the north.November 16–20: Bare branches reveal the sky.November 21–25: First flurries dust the rooftops.November 26–30: Woodsmoke curls through the block.December 1–5: Darkness settles before dinner.December 6–10: Holly and winterberry persist.December 11–15: Shortest day approaches.December 16–20: Ice begins to form at the edges.December 21–25: Solstice — the sun begins return.December 26–31: The year turns in silence.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · August 1–5

Night falls a minute earlier

Sunset retreats perceptibly — daylight shortening speeds up.

Day 214 of 365 · Wedge 43 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
March——
Aprillettuce, peas, spinach, radishes—
Maylettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Junetomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
August—tomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Octoberfall brassicas, garlic (overwinter), carrotswinter squash, tomatoes (last)
November——
December——

A year in weather

July is Allentown's warmest stretch (~75°F) and January its coldest (~29°F); precipitation crests in December at 4.3 inches and ebbs in February to 2.9 inches.

MonthMean tempPrecipRainy days
January29°3.4″14
February31°2.9″13
March40°3.7″16
April51°4.0″17
May60°4.1″17
June69°4.1″17
July75°3.4″15
August74°4.1″18
September67°3.9″15
October56°3.2″12
November43°3.8″13
December33°4.3″14

Regional context

In Allentown, NOAA NCEI 1991-2020 normals put January near 29°F and July near 75°F — a 47°F seasonal arc — with about 44.9 inches of precipitation over 180 rainy or snowy days.

Rainfall in Allentown stays even across the calendar: December tops out at 4.3 inches over 13.8 rainy days, and February still logs 2.9 inches across 12.8 — a narrow range for Allentown. That lines Allentown up with places like Fullerton, PA, Dorneyville, PA and Cetronia, PA, fed by overlapping storm tracks.

Around mid-April, Allentown sheds its freezing nights — kale, peas, spinach, and parsnips go into Allentown's beds. Tomatoes and peppers do best set out two weeks later in Allentown, once nights clear the mid-40s°F. The season ends by mid-November in Allentown, once hard frosts set back in. Allentown's low ground holds frost later into spring than Allentown's benches, which run 3-5 days ahead.

Similar climates: Fullerton, PA, Dorneyville, PA, Cetronia, PA, Catasauqua, PA, Fountain Hill, PA.

Naturalist notes

During late May, red-winged blackbirds establish territories in the wetlands around Allentown's waterways.

Apple trees throughout the region typically finish blooming by early May as temperatures stabilize.

Frequently asked

When does it freeze in Allentown?
In Allentown, expect the last spring frost near mid-April; Allentown's first autumn frost comes around mid-November.
What is the rainy season in Allentown?
December is the wettest month in Allentown, about 4.3 inches on average; the year totals roughly 45 inches.
What is the warmest month in Allentown?
Allentown peaks in July, when the mean runs near 75°F.
What is the coldest month in Allentown?
January is Allentown's coldest month, averaging about 29°F.
When can I start a vegetable garden in Allentown?
In Allentown, sow peas and hardy greens around mid-April; Allentown's tomatoes and peppers wait two weeks more.
How many rainy days does Allentown get?
Allentown averages about 180 days with measurable rain or snow each year.
What hardiness zone is Allentown?
Because Allentown bottoms near 29°F in January, that winter low sets Allentown's USDA zone — verify by ZIP.
What is the 10-day forecast for Allentown?
Allentown's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
Will it rain this week in Allentown?
See this week's day-by-day rain chances for Allentown in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Allentown?
Current conditions for Allentown and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Allentown forecast updated?
The Allentown forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Allentown?
Today's sunrise and sunset times for Allentown are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
How accurate is the weather forecast for Allentown?
The next few days in Allentown's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

The warm-summer humid continental climate of Allentown, Pennsylvania carries typical Januarys near 29°F and Julys around 75°F — 46°F of seasonal travel.

Yearly precipitation in Allentown totals around 45 inches, spread over about 180 days of rain or snow.

Allentown sits at 40.6°N; that 46°F seasonal swing frames planting windows and frost dates across Allentown.

All cities in Pennsylvania →

Philadelphia, PA weather →

ZIP codes in Allentown

  • 18104
  • 18101
  • 18103
  • 18102
  • 18109
  • 18001
  • 18105

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.