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Shaded-relief map of West Mifflin, Pennsylvania: rivers, roads, the city limits and where the water drains.
PENNSYLVANIA · ALLEGHENY COUNTY

West Mifflin

18,902 people, 1,110 ft above sea level in Allegheny County.

1,110 ftElevation, city center
18,902People, 2024 estimate
14 sq miLand area
Clear 40°
Clear now Dew point 30° · W 14 mph · high 40°
City of West Mifflin River Interstate 2 miles
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The West Mifflin plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.

MILE1
TODAY

Today in West Mifflin

NWS forecast and National Blend of Models · updated 6:00 PM EST
RIGHT NOW Pittsburgh International Airport (KPIT) · 5:51 PM
Clear
40° Clear Feels like 32° · high of 40° near 6 PM
WindW 14 mphno gusts
Humidity67%rising to 96% by morning
Pressure30.07 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 30° · Dry39° by Sunday: more humid
DryComfortableStickyMuggyOppressive
NEXT RAIN
Mostly cloudy
Tomorrow, about 7 AMin about 12 hours · 34% chance · rain
LIKELY AMOUNT0–0.1 inmost likely 0.06; 1 in 10 over 0.1
LAST RAINNov. 120.17 in · 2 dry days
ALERTS & OUTLOOKS
No watches or warnings for Allegheny County
NWS Pittsburgh and the Storm Prediction Center · checked 6:47 PM
SUN & MOON
↑ 7:04 AM5:03 PM ↓
9 h 59 m of daylight, 2 minutes less than yesterday
Waxing crescent, 26% lit. Next full moon: Nov. 24.
AIR & POLLEN
17
GOODAir quality index · fine particles
Tomorrow: 30, good. No pollen source yet.

The next three days, hour by hour

Sky: clear, cloudy, night Rain likely National Blend of Models
SATURDAY, NOV. 14
SUNDAY, NOV. 15
MONDAY, NOV. 16
TUESDAY, NOV. 17
6p
9p
Mid
3a
6a
9a
Noon
3p
6p
9p
Mid
3a
6a
9a
Noon
3p
6p
9p
Mid
3a
6a
9a
Noon
3p
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy night
rain
mostly cloudy day
mostly cloudy day
mostly cloudy day
mostly cloudy night
partly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy day
mostly cloudy day
mostly cloudy day
partly cloudy day
mostly clear night
mostly clear night
mostly clear night
mostly clear night
mostly sunny
mostly sunny
mostly sunny
clear day
TEMPERATURE °F
40°
38°
44°
38°
47°
29°
CHANCE OF RAIN
34% · 0.04 in Sunday morning 50%
WIND, MPH
14
12
9
9
8
8
10
9
6
0
0
0
0
3
6
6
0
0
0
0
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5
3
HOW IT FEELS · DEW POINT
Dry: dew points 29 to 39°

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 52° / 35°
SAT Nov. 14 Mostly cloudy Mostly cloudy
40° 35°
10% rain — W 13 A
SUN Nov. 15 Chance of showers Chance of showers
47° 35°
30% rain up to 0.1″ NW 9 A
MON Nov. 16 Mostly cloudy Mostly cloudy
49° 28°
0% rain — NW 4 A
TUE Nov. 17 Sunny Sunny
54° 28°
0% rain — SW 5 B
WED Nov. 18 Sunny Sunny
57° 30°
0% rain — S 5 B
THU Nov. 19 Mostly sunny Mostly sunny
60° 39°
0% rain — SSW 7 B
FRI Nov. 20 Mostly sunny Mostly sunny
61° 39°
0% rain — WSW 5 B
How sure are we? AModels agree: highs within 4° BSome spread: within 8° CWide spread: check back
Range from the National Blend of Models percentiles · graded on Forecast Scores
AIR MAIL

Where today’s air came from

The air arriving over West Mifflin about 5,000 feet above the ground was over Canada three days ago, and over the northern Plains a day ago, about 2,730 miles back along its path. It came down from about 15,800 feet up, warming and drying as it sank. Near the ground the air came from British Columbia; at 10,000 feet, from a point about 3,570 miles to the west. It has stayed over land, which is why it feels dry. Traced back 72 hours through NOAA’s hourly RAP analyses and the GFS beyond them, nine paths at each of three heights.

THIS WEEK, SEVEN YEARS AGO Nov. 13, 2019

The coldest this week has been

13° on Nov. 13, 2019, the coldest reading for this week of the year since 1935. Next is 17° in 2017.

17°
13°
20172019
Source: NOAA RCC-ACIS, the Pittsburgh Allegheny County Airport record since 1935.
MILE2
THE GROUND

What West Mifflin stands on

West Mifflin’s center stands about 1,110 ft above sea level. Within three miles the land runs from 710 ft to 1,230 ft, a difference of 520 ft: hilly country. The highest named summit within 15 miles is Sheppler Hill, about 1,430 ft, 15 miles south.

Under the town center the state geologic map shows Monongahela Group (limestone, shale, sandstone), from the Carboniferous, 299 to 324 million years old.

The section below crosses 4 rock units mapped at the surface.

Donora to Harmar, cut in half

A section south to north, 24 miles through the town center
800 ft1,000 ft1,200 ft WEST MIFFLIN1,110 ftMonongahela Riverabout 720 ftWilkinsburg1,220 ftO'Hara960 ft ← S · DonoraHarmar · N →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 35×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.

Rock at the surface along the line

Casselman Formation

Shale, clastic. Age: Carboniferous, 299 to 324 million years old. About 11 mi of the line.

Monongahela Group

Limestone, shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 9 mi of the line.

Glenshaw Formation

Shale. Age: Carboniferous, 299 to 324 million years old. About 3 mi of the line.

Waynesburg Formation

Sandstone, shale. Age: Carboniferous to Permian, 252 to 324 million years old. About 1 mi of the line.

From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.

Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.

MILE3
THE WATER

Where West Mifflin’s rain goes

A raindrop that lands in West Mifflin reaches the Gulf of America by way of the Monongahela, the Ohio and the Mississippi: about 1,960 river miles.

THE WAY DOWN, TO SCALE
West Mifflin≈ 1,960 mi · the Gulf of America
FROM THE CENTER OF WEST MIFFLIN ≈ 1,960 mi to the Gulf of America Monongahela → Ohio → Mississippi

970 miles of the trip are on the Ohio.

Traced down the USGS NHDPlus V2.1 river network from the Census center point of West Mifflin; river miles along the main stem, rounded.

MILE5
THE ALMANAC

West Mifflin’s year

1991–2020 normals · records since 1935 · Pittsburgh Allegheny County Airport, 3 mi west

West Mifflin has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 22° in January. About 41 inches of rain fall in a normal year.

37°22°40°24°49°31°62°42°72°52°79°60°83°64°81°63°75°56°63°45°51°35°41°28° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 TODAY WEST MIFFLIN 41.3 in rain a year
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average83° / 64°high / low, the warmest month
January, average37° / 22°high / low, the coldest month
Rain a year41.3 inwettest months: June and May
Hottest on record102°FJuly 14, 1936
Coldest on record−16°FJanuary 23, 1936
Wettest day on record6.00 inSeptember 17, 2004
90° days a year8none reach 100°
Nights at or below 32°105and 32 days that stay below freezing
Climate typeHot-summer humid continentalKöppen Dfa

AROUND THE RING

1Freeze seasonfrom the first fall freeze, about Oct. 25, to the last in spring, about April 16 (median dates)
2Lows below freezingNov. 26 to March 20; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 West Mifflin normally reaches 52° and falls to 36°. The record high is 70°, in 2011; the record low 18°, in 1942. The most rain on this date, 0.54 in, fell in 2011.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high37°40°49°62°72°79°83°81°75°63°51°41°
Normal low22°24°31°42°52°60°64°63°56°45°35°28°
Rain, inches3.082.573.223.404.084.583.933.813.543.063.033.04
Record high75° (1950)77° (2018)84° (2026)87° (1942)93° (1942)99° (2012)102° (1936)99° (1948)96° (1952)89° (2019)80° (2024)73° (2006)
Record low−16° (1936)−8° (1936)−1° (1943)15° (1950)28° (2020)38° (1945)46° (1943)46° (1935)34° (1942)25° (1942)7° (1950)−5° (1951)

Normals 1991–2020 and records since 1935 at Pittsburgh Allegheny County Airport, 3 miles west, 130 ft higher. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around West Mifflin on the Forecast Network

Neighboring plates

Pittsburgh PA · 7 MI 7 miles northwest Bethel Park PA · 7 MI 7 miles west Cleveland OH · 121 MI 121 miles northwest Columbus OH · 165 MI 165 miles west Washington DC · 184 MI 184 miles southeast Baltimore MD · 190 MI 190 miles southeast
FORECASTCITY
Map of West Mifflin, Pennsylvania. Explore the plate
PENNSYLVANIA · ALLEGHENY

West Mifflin

18,902 people, 1,110 ft above sea level in Allegheny County.

1,110 ftElevation
18,902People
14 sq miLand
Clear 40°
ClearDew point 30°
1

Today in West Mifflin

NEXT 15 HOURS
Now mostly cloudy night 40° 0%
9p mostly cloudy night 39° 2%
12a mostly cloudy night 39° 7%
3a mostly cloudy night 38° 5%
6a mostly cloudy night 38° 21%
9a mostly cloudy day 39° 26%
Mostly cloudy
NEXT RAINTomorrow about 7 AM · 34%
→
Sat10%
Mostly cloudy Mostly cloudy
35
40
A
Sun30%
Chance of showers Chance of showers
35
47
A
Mon0%
Mostly cloudy Mostly cloudy
28
49
A
Tue0%
Sunny Sunny
28
54
B
Wed0%
Sunny Sunny
30
57
B
Thu0%
Mostly sunny Mostly sunny
39
60
B
Fri0%
Mostly sunny Mostly sunny
39
61
B
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
THIS WEEK, SEVEN YEARS AGO · NOV. 13, 2019

13°, the coldest this week of the year has been since 1935.

2

What West Mifflin stands on

West Mifflin’s center stands about 1,110 ft above sea level. Within three miles the land runs from 710 ft to 1,230 ft, a difference of 520 ft: hilly country. The highest named summit within 15 miles is Sheppler Hill, about 1,430 ft, 15 miles south.

West Mifflin, south to north West Mifflin1,110 ftMonongahela Riverabout 720 ft ← SN → 24 miles through the town center; vertical exaggeration about 67×. Colors: rock at the surface.
Elevation, center1,110 ft
Within 3 miles710 to 1,230 ft
Lie of the landHilly (520 ft of relief)
High point nearbySheppler Hill, 1,430 ft, 15 mi south
Rock at the surfaceMonongahela Group
Its ageCarboniferous, 299 to 324 million years old
5

West Mifflin’s year

West Mifflin has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 22° in January. About 41 inches of rain fall in a normal year.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 41.3 in
July, average83° / 64° · high / low, the warmest month
January, average37° / 22° · high / low, the coldest month
Rain a year41.3 in · wettest months: June and May
Hottest on record102°F · July 14, 1936
Coldest on record−16°F · January 23, 1936
Wettest day on record6.00 in · September 17, 2004
90° days a year8 · none reach 100°
Nights at or below 32°105 · and 32 days that stay below freezing
Climate typeHot-summer humid continental · Köppen Dfa
1Freeze season · from the first fall freeze, about Oct. 25, to the last in spring, about April 16 (median dates)
2Lows below freezing · Nov. 26 to March 20; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 West Mifflin normally reaches 52° and falls to 36°. The record high is 70°, in 2011; the record low 18°, in 1942. The most rain on this date, 0.54 in, fell in 2011.

Normals 1991–2020 and records since 1935 at Pittsburgh Allegheny County Airport, 3 miles west, 130 ft higher. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,960 mito the Gulf of AmericaMonongahela → Ohio → Mississippi

A raindrop that lands in West Mifflin reaches the Gulf of America by way of the Monongahela, the Ohio and the Mississippi: about 1,960 river miles.

970 miles of the trip are on the Ohio.