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Bryn Mawr, Pennsylvania Weather

Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →

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

Bryn Mawr, PA
Saturday, July 4 at 8:24 AM
82
°
Clear
Feels like
86°
Humidity
62%
Wind
6 mph
Sunrise
1:37 AM
Sunset
4:33 PM
Bryn Mawr, PA
Hour by hour · 24h
24-Hour ForecastBryn Mawr, PA: 24-hour forecast. Temperatures range from 73 to 101 degrees Fahrenheit with a 44% chance of precipitation at 10 PM.
L 73°H 101°
Bryn Mawr, PA
7-day forecast
  1. Today
    Jul 4
    Light Drizzle
    44%
    0.02″
    101°75°—
  2. Sunday
    Jul 5
    Rain
    88%
    0.69″
    95°70°-6°
  3. Monday
    Jul 6
    T-storm w/ Hail
    88%
    0.30″
    76°65°-19°
  4. Tuesday
    Jul 7
    Light Drizzle
    72%
    0.01″
    67°61°-9°
  5. Wednesday
    Jul 8
    Partly Cloudy
    16%
    —
    84°58°+17°
  6. Thursday
    Jul 9
    Light Drizzle
    28%
    —
    90°66°+6°
  7. Friday
    Jul 10
    Light Drizzle
    34%
    —
    92°71°+2°
Bryn Mawr, PA
Next 24 hours · Warm now
HOT 90°65°88°110°6a12p6p12anow 81°high 101°low 73°PRECIP %
Bryn Mawr, PA
Anemometer · 24h winds · from true
NESW
From · True
WNW
289° · veering 6°
Direction
WNW
289°
Sustained
6
mph
Gust
14
mph
Peak 24h
26
avg 7
Beaufort · 2 · LIGHT 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 7 · pk 26 @ 8:00p
01020304050MPHB1B2B3B4B5B6B7B8B9-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 435SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 6° from the wnw.
Bryn Mawr, PA
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
998.8
-0.1 mb in 3h · steady · 29.49 inHg
Now
998.8
mb
3h
-0.1
mb
12h
-0.3
mb
24h
-3.3
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 998–1002
9909951000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW1001.9998.1998.6
−24h−18h−12h−6hnow
Deep low — expect rough seas, strong wind, and persistent rain.
Bryn Mawr, PA
Air quality
64
AQI
Moderate
↑+8 in 6h▲Peak ~71 @ 6 PM

AQI 64 (Moderate), driven by PM2.5. AQI up 8 over the last 6 hours (gradual rise). PM2.5 at 20.0 µg/m³ (AQI 71) with a 0.89 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 6 PM.

PM 2.5DRIVERModerate
20.0μg/m³
PM 10Good
22μg/m³
NO₂Good
10μg/m³
OzoneModerate
96μg/m³
UV IndexLow
1.4

What's driving it

Ozone × UV × Sky

Ozone at AQI 45 now. With UV 4.7 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 28 around 1 PM.

Present
AQI 45
UV peak
4.7 at 1 PM
Sky at peak
clear
Projected peak
AQI 28

PM × Wind × Precip

PM2.5 at 20.0 µg/m³ (AQI 71) with a 0.89 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.

PM2.5/PM10
0.89
Wind
light
Recent rain
0h in last 6h
Pattern
stagnant smoke

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 TREND50100SATSUNMONTUEWEDTHUFRISAT7-DAY PM2.5 TREND · μg/m³450
Bryn Mawr, PA
Sky cover · visibility · 24h
Cloud cover
0%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
60.3mi
UNLIMITED
91 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
12:24 UTC · Bryn Mawr, 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
12:24 UTC · Bryn Mawr, PA · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Bryn Mawr, PA
Satellite · infrared · animated
Bryn Mawr, PA
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Bryn Mawr, PA
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:06 AM
Sunrise
1:37 AM
Daylight
14h 56m
Sunset
4:33 PM
Civil dusk
9:07 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Bryn Mawr, PA
The moon
Waning Gibbous
82% illuminated
Moonrise
10:55 PM
Moonset
10:05 AM
In sign
♓︎ Pisces
Bryn Mawr, PA
Microseason
Jul 1–5

Cicadas claim the afternoon

plant
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Bryn Mawr at a glance

  • Today vs. normal: 10°F above the seasonal normal for this latitude
  • Last frost: April 16 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP code: 19010

16-Day Forecast — Bryn Mawr

  1. Sat101°75°44%
  2. Sun95°70°88%
  3. Mon76°65°88%
  4. Tue67°61°72%
  5. Wed84°58°16%
  6. Thu90°66°28%
  7. Fri92°71°34%
  8. Sat82°71°33%
  9. Sun73°66°31%
  10. Mon71°66°16%
  11. Tue83°64°16%
  12. Wed89°67°24%
  13. Thu93°73°23%
  14. Fri95°77°34%
  15. Sat78°70°39%
  16. Sun88°69°35%

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

Right now in the garden

Peak growing season

As of July 4, 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 — Bryn Mawr

SPC has placed Bryn Mawr in the Slight Risk category for severe thunderstorms today.

  • TODAYSLGTSlight Risk
  • TOMORROWSLGTSlight Risk
  • DAY 3TSTMGeneral Thunderstorms

Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.

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.

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 · July 1–5

Cicadas claim the afternoon

Annual cicada buzz begins, peaking in the heat of the day.

Day 185 of 365 · Wedge 37 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 Bryn Mawr's warmest stretch (~77°F) and January its coldest (~31°F); precipitation crests in December at 4.2 inches and ebbs in February to 2.9 inches.

MonthMean tempPrecipRainy days
January31°3.4″13
February33°2.9″12
March42°3.7″15
April53°3.9″17
May61°3.7″17
June71°3.7″17
July77°3.3″16
August75°4.0″17
September69°3.7″13
October58°3.0″11
November45°3.6″13
December36°4.2″13

Regional context

Bryn Mawr swings from 31°F in January to 77°F in July (46°F) per NOAA NCEI 1991-2020 normals; precipitation in Bryn Mawr runs about 43.1 inches on roughly 173 measurable days.

Bryn Mawr's precipitation spreads evenly: December peaks at 4.2 inches on 13.0 wet days, while February holds 2.9 inches over 12.4 — no month dominates Bryn Mawr's rain calendar. That even rhythm groups Bryn Mawr with places like Rosemont, PA, Haverford College, PA and Ardmore, PA.

Once Bryn Mawr passes mid-April, overnight freezes fade and peas, lettuce, spinach, and radishes can be sown. Tomatoes and peppers do best set out two weeks later in Bryn Mawr, once nights clear the mid-40s°F. Frost returns to Bryn Mawr near mid-November, ending the tender-crop season. A creek-bottom lot in Bryn Mawr can lag Bryn Mawr's last frost 7-10 days behind a south slope.

Similar climates: Rosemont, PA, Haverford College, PA, Ardmore, PA, Villanova, PA, Wynnewood, PA.

Frequently asked

When does it freeze in Bryn Mawr?
In Bryn Mawr, expect the last spring frost near mid-April; Bryn Mawr's first autumn frost comes around mid-November.
What is the rainy season in Bryn Mawr?
December is the wettest month in Bryn Mawr, about 4.2 inches on average; the year totals roughly 43 inches.
What is the warmest month in Bryn Mawr?
On average July tops the year in Bryn Mawr at about 77°F.
What is the coldest month in Bryn Mawr?
The coldest stretch in Bryn Mawr falls in January, around 31°F on average.
When can I start a vegetable garden in Bryn Mawr?
Hardy spring crops go in near mid-April in Bryn Mawr; tender peppers and squash wait 10–14 days.
How many rainy days does Bryn Mawr get?
Expect roughly 173 wet days a year in Bryn Mawr.
What hardiness zone is Bryn Mawr?
Because Bryn Mawr bottoms near 31°F in January, that winter low sets Bryn Mawr's USDA zone — verify by ZIP.
What is the 10-day forecast for Bryn Mawr?
Bryn Mawr'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 Bryn Mawr?
See this week's day-by-day rain chances for Bryn Mawr in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Bryn Mawr?
Current conditions for Bryn Mawr and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Bryn Mawr forecast updated?
The Bryn Mawr forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Bryn Mawr?
Today's sunrise and sunset times for Bryn Mawr 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 Bryn Mawr?
The next few days in Bryn Mawr's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

In Bryn Mawr, Pennsylvania, the warm-summer humid continental climate runs from about 31°F in January to 77°F in July, a 46°F seasonal range.

Across the year, Bryn Mawr collects about 43 inches of precipitation over roughly 173 days with measurable rain or snow.

Bryn Mawr's 46°F range, set by its 40.0°N position, drives frost timing and what thrives in Bryn Mawr.

All cities in Pennsylvania →

Philadelphia, PA weather →

ZIP codes in Bryn Mawr

  • 19041
  • 19010

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.