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

Slippery Rock

8,396 people, 1,320 ft above sea level in Butler County.

1,320 ftElevation, city center
8,396People, 2024 estimate
26 sq miLand area
Sunny 37°
Sunny now Dew point 36° · WSW 15 mph · high 41°
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 4:00 PM EST
RIGHT NOW Youngstown-Warren Regional Airport (KYNG) · 4:51 PM
Sunny
37° Sunny Feels like 28° · high of 41° near 5 PM
WindWSW 15 mphgusts 23
Humidity96%rising to 100% by morning
Pressure30.04 in →steady
Visibility8 mihazy
CloudsClear
UV index—no forecast
Dew point 36° · Dryabout the same for three days
DryComfortableStickyMuggyOppressive
NEXT RAIN
Rain
Tomorrow, about 4 AMin about 11 hours · 40% chance · rain
LIKELY AMOUNT—amounts come within 3 days
LAST RAINNov. 120.4 in · 2 dry days
ALERTS & OUTLOOKS
No watches or warnings for Butler County
NWS Pittsburgh and the Storm Prediction Center · checked 5:17 PM
SUN & MOON
↑ 7:06 AM5:02 PM ↓
9 h 56 m of daylight, 2 minutes less than yesterday
Waxing crescent, 26% lit. Next full moon: Nov. 24.
AIR & POLLEN
19
GOODAir quality index · ozone
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
5p
8p
11p
2a
5a
8a
11a
2p
5p
8p
11p
2a
5a
8a
11a
2p
5p
8p
11p
2a
5a
8a
11a
2p
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy night
rain
mostly cloudy day
partly cloudy day
mostly cloudy day
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy day
mostly cloudy day
mostly cloudy day
partly cloudy night
mostly clear night
mostly clear night
mostly clear night
mostly clear night
mostly sunny
clear day
clear day
TEMPERATURE °F
41°
37°
44°
38°
47°
29°
CHANCE OF RAIN
40% · 0.02 in Sunday overnight 50%
WIND, MPH
13
12
10
9
8
8
10
10
6
5
4
3
3
4
5
5
2
0
2
4
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5
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
41° 33°
30% rain — WNW 12 A
SUN Nov. 15 Chance of showers Chance of showers
46° 34°
40% rain up to 0.05″ NNW 9 A
MON Nov. 16 Mostly cloudy Mostly cloudy
48° 26°
0% rain — WNW 4 A
TUE Nov. 17 Sunny Sunny
52° 27°
0% rain — SW 3 A
WED Nov. 18 Mostly sunny Mostly sunny
55° 29°
0% rain — S 6 A
THU Nov. 19 Partly cloudy Partly cloudy
58° 38°
0% rain — SSW 8 B
FRI Nov. 20 Mostly sunny Mostly sunny
59° 38°
0% rain — SW 1 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 2,310 miles back along its path. Near the ground the air came from British Columbia; at 10,000 feet, from a point about 3,380 miles to the west. 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 1,320 ft above sea level. Within three miles the land runs from 1,140 ft to 1,430 ft, a difference of 290 ft: rolling country. The highest named summit within 15 miles is Eakin Knob, about 1,590 ft, 15 miles east-northeast.

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 4 rock units mapped at the surface.

Prospect to Wolf Creek, cut in half

A section south to north, 24 miles through the town center
1,200 ft1,400 ft1,600 ft SLIPPERY ROCK1,320 ftHigh point of the line1,620 ftSlippery Rock Creekabout 1,160 ftPine1,380 ft ← S · ProspectWolf Creek · N →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 40×. 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 11 mi of the line.

Pottsville Formation

Sandstone, conglomerate. Age: Carboniferous, 299 to 324 million years old. About 7 mi of the line.

Glenshaw Formation

Shale. Age: Carboniferous, 299 to 324 million years old. About 5 mi of the line.

Shenango Formation

Sandstone. Age: Carboniferous, 324 to 359 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 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 1,970 river miles.

THE WAY DOWN, TO SCALE
Slippery Rock≈ 1,970 mi · the Gulf of America
FROM THE CENTER OF SLIPPERY ROCK ≈ 1,970 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

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, here. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around Slippery Rock on the Forecast Network

Neighboring plates

Cranberry PA · 25 MI 25 miles south Youngstown OH · 32 MI 32 miles west Pittsburgh PA · 43 MI 43 miles south Cleveland OH · 90 MI 90 miles west Buffalo NY · 140 MI 140 miles northeast Detroit MI · 183 MI 183 miles northwest
FORECASTCITY
Map of Slippery Rock, Pennsylvania. Explore the plate
PENNSYLVANIA · BUTLER

Slippery Rock

8,396 people, 1,320 ft above sea level in Butler County.

1,320 ftElevation
8,396People
26 sq miLand
Sunny 37°
SunnyDew point 36°
1

Today in Slippery Rock

NEXT 15 HOURS
Now mostly cloudy night 41° 11%
8p mostly cloudy night 39° 27%
11p mostly cloudy night 38° 19%
2a mostly cloudy night 38° 27%
5a mostly cloudy night 38° 29%
8a mostly cloudy day 38° 8%
Rain
NEXT RAINTomorrow about 4 AM · 40%
→
Sat30%
Mostly cloudy Mostly cloudy
33
41
A
Sun40%
Chance of showers Chance of showers
34
46
A
Mon0%
Mostly cloudy Mostly cloudy
26
48
A
Tue0%
Sunny Sunny
27
52
A
Wed0%
Mostly sunny Mostly sunny
29
55
A
Thu0%
Partly cloudy Partly cloudy
38
58
B
Fri0%
Mostly sunny Mostly sunny
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 1,320 ft above sea level. Within three miles the land runs from 1,140 ft to 1,430 ft, a difference of 290 ft: rolling country. The highest named summit within 15 miles is Eakin Knob, about 1,590 ft, 15 miles east-northeast.

Slippery Rock, south to north Slippery Rock1,320 ftSlippery Rock Creekabout 1,160 ft ← SN → 24 miles through the town center; vertical exaggeration about 76×. Colors: rock at the surface.
Elevation, center1,320 ft
Within 3 miles1,140 to 1,430 ft
Lie of the landRolling (290 ft of relief)
High point nearbyEakin Knob, 1,590 ft, 15 mi east-northeast
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, here. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,970 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 1,970 river miles.

970 miles of the trip are on the Mississippi.