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Shaded-relief map of Slippery Rock, Pennsylvania: rivers, roads, the city limits and where the water drains.
PENNSYLVANIA · LAWRENCE COUNTY

Slippery Rock

2,860 people, 1,290 ft above sea level in Lawrence County.

1,290 ftElevation, city center
2,860People, 2024 estimate
30 sq miLand area
Clear 36°
Clear now Dew point 35° · W 10 mph · high 38°
City of Slippery Rock River Interstate 2 miles
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The Slippery Rock 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 Slippery Rock

NWS forecast and National Blend of Models · updated 8:00 PM EST
RIGHT NOW Youngstown-Warren Regional Airport (KYNG) · 8:51 PM
Clear
36° Clear Feels like 28° · high of 38° near 9 PM
WindW 10 mphno gusts
Humidity96%rising to 100% by morning
Pressure30.10 in →steady
Visibility8 mihazy
CloudsClear
UV index—no forecast
Dew point 35° · Dryabout the same for three days
DryComfortableStickyMuggyOppressive
NEXT RAIN
Rain
Tomorrow, about 2 AMin about 5 hours · 46% chance · rain
LIKELY AMOUNT—amounts come within 3 days
LAST RAINNov. 130.02 in · 1 dry day
ALERTS & OUTLOOKS
No watches or warnings for Lawrence County
NWS Pittsburgh and the Storm Prediction Center · checked 9:17 PM
SUN & MOON
↑ 7:07 AM5:03 PM ↓
9 h 56 m of daylight, 2 minutes less than yesterday
Waxing crescent, 27% lit. Next full moon: Nov. 24.
AIR & POLLEN
21
GOODAir quality index · fine particles
Tomorrow: 20, 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
9p
Mid
3a
6a
9a
Noon
3p
6p
9p
Mid
3a
6a
9a
Noon
3p
6p
9p
Mid
3a
6a
9a
Noon
3p
6p
mostly cloudy night
mostly cloudy night
rain
mostly cloudy day
mostly cloudy day
mostly cloudy day
mostly cloudy day
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy day
mostly cloudy day
mostly cloudy day
partly cloudy day
partly cloudy night
mostly clear night
mostly clear night
mostly clear night
mostly sunny
mostly sunny
clear day
clear day
clear night
TEMPERATURE °F
38°
37°
44°
38°
47°
29°
50°
CHANCE OF RAIN
46% · 0.05 in Sunday overnight 50%
WIND, MPH
10
9
9
8
9
10
9
5
5
5
3
3
5
6
5
0
0
3
5
5
5
6
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 50° / 34°
SAT Nov. 14 Mostly cloudy Mostly cloudy
38° 37°
20% rain — WNW 11 A
SUN Nov. 15 Chance of showers; warmer Chance of showers; warmer
46° 34°
50% rain — NNW 9 A
MON Nov. 16 Mostly cloudy Mostly cloudy
48° 27°
0% rain — WNW 5 A
TUE Nov. 17 Sunny Sunny
52° 27°
0% rain — SW 3 A
WED Nov. 18 Mostly sunny Mostly sunny
55° 31°
0% rain — S 6 B
THU Nov. 19 Partly cloudy Partly cloudy
58° 39°
0% rain — SSW 9 B
FRI Nov. 20 Partly cloudy Partly cloudy
59° 38°
0% rain — SW 3 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 Slippery Rock about 5,000 feet above the ground was over British Columbia three days ago, and over the Great Lakes a day ago, about 2,210 miles back along its path. Near the ground the air came from British Columbia; at 10,000 feet, from the open Pacific. It feels dry all the same. Traced back 72 hours through NOAA’s hourly RAP analyses and the GFS beyond them, nine paths at each of three heights.

THIS WEEK IN 2010 Nov. 12, 2010

The hottest this week has been

78° on Nov. 12, 2010, the hottest reading for this week of the year since 1949. Next is 75° in 2009.

75°
78°
20092010
Source: NOAA RCC-ACIS, the Slippery Rock 1 SSW record since 1949.
MILE2
THE GROUND

What Slippery Rock stands on

Slippery Rock’s center stands about 1,290 ft above sea level. Within three miles the land runs from 1,070 ft to 1,400 ft, a difference of 330 ft: rolling country.

Under the town center the state geologic map shows Allegheny Formation (sandstone), from the Carboniferous, 299 to 324 million years old.

The section below crosses 3 rock units mapped at the surface.

North Beaver to Unionville, cut in half

A section west to east, 24 miles through the town center
750 ft1,000 ft1,250 ft1,500 ft SLIPPERY ROCK1,290 ftNorth Beaver1,050 ftMahoning Riverabout 760 ftSouth New Castle1,180 ftShenango1,220 ftSlippery Rock Creekabout 1,100 ftHigh point of the line1,530 ft ← W · North BeaverUnionville · E →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 25×. 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

Allegheny Formation

Sandstone. Age: Carboniferous, 299 to 324 million years old. About 21 mi of the line.

Pottsville Formation

Sandstone, conglomerate. Age: Carboniferous, 299 to 324 million years old. About 2 mi of the line.

Glenshaw Formation

Shale. Age: Carboniferous, 299 to 324 million years old. About 0.7 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 Slippery Rock’s rain goes

A raindrop that lands in Slippery Rock reaches the Gulf of America by way of Slippery Rock Creek, Connoquenessing Creek, the Beaver, the Ohio and the Mississippi: about 1,950 river miles.

THE WAY DOWN, TO SCALE
Slippery Rock≈ 1,950 mi · the Gulf of America
FROM THE CENTER OF SLIPPERY ROCK ≈ 1,950 mi to the Gulf of America Slippery Rock Creek → Connoquenessing Creek → Beaver → Ohio → Mississippi

970 miles of the trip are on the Mississippi.

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

MILE5
THE ALMANAC

Slippery Rock’s year

1991–2020 normals · records since 1949 · Slippery Rock 1 SSW, 11 mi northeast

Slippery Rock has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about 17° in January. About 45 inches of rain fall in a normal year.

33°17°37°18°46°25°59°35°69°45°77°54°81°58°80°56°74°50°62°39°49°31°38°23° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 TODAY 45.2 in rain a year
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average81° / 58°high / low, the warmest month
January, average33° / 17°high / low, the coldest month
Rain a year45.2 inwettest months: June and July
Hottest on record102°FJuly 23, 2011
Coldest on record−28°FJanuary 19, 1994
Wettest day on record4.71 inSeptember 8, 2004
Snowiest day on record17.0 inNovember 25, 1950
90° days a year13very few reach 100°
Nights at or below 32°143and 31 days that stay below freezing
Climate typeWarm-summer humid continentalKöppen Dfb

AROUND THE RING

1Freeze seasonfrom the first fall freeze, about Oct. 12, to the last in spring, about May 10 (median dates)
2Lows below freezingNov. 8 to April 9; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 Slippery Rock normally reaches 50° and falls to 31°. The record high is 75°, in 2009; the record low 8°, in 1986. The most rain on this date, 1.15 in, fell in 1972.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high33°37°46°59°69°77°81°80°74°62°49°38°
Normal low17°18°25°35°45°54°58°56°50°39°31°23°
Rain, inches3.472.693.413.944.144.764.634.024.073.453.473.19
Record high72° (1950)74° (2017)87° (2012)89° (2009)96° (2015)99° (1952)102° (2011)99° (1953)99° (1953)91° (2007)81° (1961)74° (1982)
Record low−28° (1994)−21° (1979)−10° (1993)9° (1987)22° (1983)30° (1990)37° (1979)28° (1982)27° (1991)12° (1975)−1° (1958)−20° (1989)

Normals 1991–2020 and records since 1949 at Slippery Rock 1 SSW, 11 miles northeast. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around Slippery Rock on the Forecast Network

Neighboring plates

Youngstown OH · 24 MI 24 miles northwest Pittsburgh PA · 38 MI 38 miles south Cleveland OH · 84 MI 84 miles northwest Columbus OH · 160 MI 160 miles southwest Detroit MI · 178 MI 178 miles northwest Toledo OH · 181 MI 181 miles west
FORECASTCITY
Map of Slippery Rock, Pennsylvania. Explore the plate
PENNSYLVANIA · LAWRENCE

Slippery Rock

2,860 people, 1,290 ft above sea level in Lawrence County.

1,290 ftElevation
2,860People
30 sq miLand
Clear 36°
ClearDew point 35°
1

Today in Slippery Rock

NEXT 15 HOURS
Now mostly cloudy night 38° 8%
12a mostly cloudy night 38° 17%
3a rain 38° 32%
6a mostly cloudy night 38° 28%
9a mostly cloudy day 40° 7%
12p mostly cloudy day 43° 2%
Rain
NEXT RAINTomorrow about 2 AM · 46%
→
Sat20%
Mostly cloudy Mostly cloudy
37
38
A
Sun50%
Chance of showers; warmer Chance of showers; warmer
34
46
A
Mon0%
Mostly cloudy Mostly cloudy
27
48
A
Tue0%
Sunny Sunny
27
52
A
Wed0%
Mostly sunny Mostly sunny
31
55
B
Thu0%
Partly cloudy Partly cloudy
39
58
B
Fri0%
Partly cloudy Partly cloudy
38
59
B
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
THIS WEEK IN 2010 · NOV. 12, 2010

78°, the hottest this week of the year has been since 1949.

2

What Slippery Rock stands on

Slippery Rock’s center stands about 1,290 ft above sea level. Within three miles the land runs from 1,070 ft to 1,400 ft, a difference of 330 ft: rolling country.

Slippery Rock, west to east Slippery Rock1,290 ftMahoning Riverabout 760 ftSlippery Rock Creekabout 1,100 ft ← WE → 24 miles through the town center; vertical exaggeration about 48×. Colors: rock at the surface.
Elevation, center1,290 ft
Within 3 miles1,070 to 1,400 ft
Lie of the landRolling (330 ft of relief)
Rock at the surfaceAllegheny Formation
Its ageCarboniferous, 299 to 324 million years old
5

Slippery Rock’s year

Slippery Rock has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about 17° in January. About 45 inches of rain fall in a normal year.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 45.2 in
July, average81° / 58° · high / low, the warmest month
January, average33° / 17° · high / low, the coldest month
Rain a year45.2 in · wettest months: June and July
Hottest on record102°F · July 23, 2011
Coldest on record−28°F · January 19, 1994
Wettest day on record4.71 in · September 8, 2004
Snowiest day on record17.0 in · November 25, 1950
90° days a year13 · very few reach 100°
Nights at or below 32°143 · and 31 days that stay below freezing
Climate typeWarm-summer humid continental · Köppen Dfb
1Freeze season · from the first fall freeze, about Oct. 12, to the last in spring, about May 10 (median dates)
2Lows below freezing · Nov. 8 to April 9; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 Slippery Rock normally reaches 50° and falls to 31°. The record high is 75°, in 2009; the record low 8°, in 1986. The most rain on this date, 1.15 in, fell in 1972.

Normals 1991–2020 and records since 1949 at Slippery Rock 1 SSW, 11 miles northeast. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,950 mito the Gulf of AmericaSlippery Rock Creek → Connoquenessing Creek → Beaver → Ohio → Mississippi

A raindrop that lands in Slippery Rock reaches the Gulf of America by way of Slippery Rock Creek, Connoquenessing Creek, the Beaver, the Ohio and the Mississippi: about 1,950 river miles.

970 miles of the trip are on the Mississippi.