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Shaded-relief map of South Mount Vernon, Ohio: rivers, roads, the city limits and where the water drains.
OHIO · KNOX COUNTY

South Mount Vernon

714 people, 1,020 ft above sea level in Knox County.

1,020 ftElevation, city center
714People, 2024 estimate
0 sq miLand area
Sunny 37°
Sunny now Dew point 36° · NW 8 mph · high 40°
City of South Mount Vernon River Interstate 2 miles
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The South Mount Vernon 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 South Mount Vernon

NWS forecast and National Blend of Models · updated 3:00 PM EST
RIGHT NOW Knox County Airfield (K4I3) · 3:55 PM
Sunny
37° Sunny Feels like 31° · high of 40° near 4 PM
WindNW 8 mphno gusts
Humidity93%rising to 100% by morning
Pressure30.12 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 36° · Dryabout the same for three days
DryComfortableStickyMuggyOppressive
NEXT RAIN
Clear
Not this weeknone in the forecast for a week
LIKELY AMOUNT—nothing expected
LAST RAINNov. 130.67 in · 1 dry day
ALERTS & OUTLOOKS
No watches or warnings for Knox County
NWS Cleveland and the Storm Prediction Center · checked 4:17 PM
SUN & MOON
↑ 7:14 AM5:14 PM ↓
9 h 59 m of daylight, 2 minutes less than yesterday
Waxing crescent, 25% lit. Next full moon: Nov. 24.
AIR & POLLEN
15
GOODAir quality index · fine particles
Tomorrow: 39, 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
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overcast
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy day
partly cloudy day
mostly cloudy day
mostly cloudy night
partly cloudy night
partly cloudy night
mostly cloudy night
partly cloudy night
partly cloudy day
mostly sunny
mostly sunny
mostly clear night
mostly clear night
clear night
mostly clear night
mostly clear night
mostly sunny
clear day
clear day
TEMPERATURE °F
40°
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CHANCE OF RAIN
50%
WIND, MPH
8
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HOW IT FEELS · DEW POINT
Dry: dew points 32 to 39° ↑ Humid air returns More humid: 36° by Tuesday

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 80° / 62°
SAT Nov. 14 Cloudy Cloudy
40° 33°
0% rain — WNW 9 A
SUN Nov. 15 Mostly cloudy Mostly cloudy
46° 30°
0% rain — NW 6 A
MON Nov. 16 Partly cloudy Partly cloudy
50° 30°
0% rain — WSW 2 A
TUE Nov. 17 Sunny Sunny
53° 31°
0% rain — SSW 2 A
WED Nov. 18 Mostly sunny Mostly sunny
56° 34°
0% rain — S 3 A
THU Nov. 19 Partly cloudy Partly cloudy
59° 42°
0% rain — SSW 6 B
FRI Nov. 20 Partly cloudy Partly cloudy
61° 42°
0% rain — S 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 South Mount Vernon about 5,000 feet above the ground was over the Gulf of Alaska three days ago, and over the northern Plains a day ago, about 2,900 miles back along its path. It came down from about 13,100 feet up, warming and drying as it sank. Near the ground the air came from British Columbia; at 10,000 feet, from the Pacific north of Hawaii. 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, SIX YEARS AGO Nov. 11, 2020

The hottest this week has been

77° on Nov. 11, 2020, the hottest reading for this week of the year since 1950. Next is 76° in 1994.

76°
77°
19942020
Source: NOAA RCC-ACIS, the Centerburg 2 SE record since 1950.
MILE2
THE GROUND

What South Mount Vernon stands on

South Mount Vernon’s center stands about 1,020 ft above sea level. Within three miles the land runs from 970 ft to 1,290 ft, a difference of 320 ft: rolling country. The highest named summit within 15 miles is Hulse Hill, about 1,410 ft, 11 miles west.

Under the town center the state geologic map shows Maxville Limestone; Rushville, Logan, and Cuyhoga Formations, Undivided (shale, siltstone, sandstone), from the Devonian to Carboniferous, 324 to 422 million years old.

The section below crosses 2 rock units mapped at the surface.

South Mount Vernon, cut in half from west to east

A section west to east, 24 miles through the town center
1,000 ft1,200 ft1,400 ft SOUTH MOUNT VERNON1,020 ftHulse Hill1,410 ftHigh point of the line1,430 ftMount Vernon970 ftGambier1,140 ftKokosing Riverabout 930 ft ← W · SpartaE →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 36×. 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

Maxville Limestone; Rushville, Logan, and Cuyhoga Formations, Undivided

Shale, siltstone, sandstone. Age: Devonian to Carboniferous, 324 to 422 million years old. About 22 mi of the line.

Black Hand Sandstone Member of Cuyahoga Formation

Sandstone, conglomerate. Age: Carboniferous, 324 to 359 million years old. About 2 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 South Mount Vernon’s rain goes

A raindrop that lands in South Mount Vernon reaches the Gulf of America by way of the Kokosing, the Walhonding, the Muskingum, the Ohio and the Mississippi: about 1,930 river miles.

THE WAY DOWN, TO SCALE
South Mount Vernon≈ 1,930 mi · the Gulf of America
FROM THE CENTER OF SOUTH MOUNT VERNON ≈ 1,930 mi to the Gulf of America Kokosing → Walhonding → Muskingum → 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 South Mount Vernon; river miles along the main stem, rounded.

MILE5
THE ALMANAC

South Mount Vernon’s year

1991–2020 normals · records since 1950 · Centerburg 2 SE, 10 mi southwest

South Mount Vernon has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 17° in January. About 44 inches of rain fall in a normal year.

34°17°37°19°48°27°62°38°72°49°80°58°83°61°82°59°75°52°63°41°50°31°39°23° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 TODAY 44.2 in rain a year
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average83° / 61°high / low, the warmest month
January, average34° / 17°high / low, the coldest month
Rain a year44.2 inwettest months: June and May
Hottest on record100°FJuly 14, 1954
Coldest on record−29°FJanuary 19, 1994
Wettest day on record5.18 inSeptember 14, 1979
Snowiest day on record15.0 inFebruary 6, 2026
90° days a year9none reach 100°
Nights at or below 32°128and 40 days that stay below freezing
Climate typeHot-summer humid continentalKöppen Dfa

AROUND THE RING

1Freeze seasonfrom the first fall freeze, about Oct. 17, to the last in spring, about April 27 (median dates)
2Lows below freezingNov. 11 to March 31; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 South Mount Vernon normally reaches 51° and falls to 32°. The record high is 71°, in 1989; the record low 4°, in 2019. The most rain on this date, 1.20 in, fell in 1972.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high34°37°48°62°72°80°83°82°75°63°50°39°
Normal low17°19°27°38°49°58°61°59°52°41°31°23°
Rain, inches3.062.533.444.484.545.034.213.853.582.973.273.24
Record high67° (2020)74° (2017)85° (2026)87° (2009)92° (1964)99° (1988)100° (1954)98° (1953)97° (1954)91° (2019)80° (2016)74° (1982)
Record low−29° (1994)−20° (2015)−11° (1960)5° (1964)20° (1966)32° (1972)40° (1963)36° (1965)28° (1959)18° (1962)−10° (1958)−23° (1989)

Normals 1991–2020 and records since 1950 at Centerburg 2 SE, 10 miles southwest, 180 ft higher. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around South Mount Vernon on the Forecast Network

Neighboring plates

Newark OH · 22 MI 22 miles south Columbus OH · 38 MI 38 miles southwest Cleveland OH · 87 MI 87 miles northeast Pittsburgh PA · 133 MI 133 miles east Cincinnati OH · 137 MI 137 miles southwest Detroit MI · 142 MI 142 miles north
FORECASTCITY
Map of South Mount Vernon, Ohio. Explore the plate
OHIO · KNOX

South Mount Vernon

714 people, 1,020 ft above sea level in Knox County.

1,020 ftElevation
714People
0 sq miLand
Sunny 37°
SunnyDew point 36°
1

Today in South Mount Vernon

NEXT 15 HOURS
Now overcast 40° 0%
7p mostly cloudy night 40° 1%
10p mostly cloudy night 39° 1%
1a mostly cloudy night 37° 1%
4a mostly cloudy night 37° 1%
7a mostly cloudy day 35° 1%
Clear
NEXT RAINNone this week
→
Sat0%
Cloudy Cloudy
33
40
A
Sun0%
Mostly cloudy Mostly cloudy
30
46
A
Mon0%
Partly cloudy Partly cloudy
30
50
A
Tue0%
Sunny Sunny
31
53
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Wed0%
Mostly sunny Mostly sunny
34
56
A
Thu0%
Partly cloudy Partly cloudy
42
59
B
Fri0%
Partly cloudy Partly cloudy
42
61
B
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
THIS WEEK, SIX YEARS AGO · NOV. 11, 2020

77°, the hottest this week of the year has been since 1950.

2

What South Mount Vernon stands on

South Mount Vernon’s center stands about 1,020 ft above sea level. Within three miles the land runs from 970 ft to 1,290 ft, a difference of 320 ft: rolling country. The highest named summit within 15 miles is Hulse Hill, about 1,410 ft, 11 miles west.

South Mount Vernon, west to east South Mount Vernon1,020 ftHulse Hill1,410 ftKokosing Riverabout 930 ft ← WE → 24 miles through the town center; vertical exaggeration about 68×. Colors: rock at the surface.
Elevation, center1,020 ft
Within 3 miles970 to 1,290 ft
Lie of the landRolling (320 ft of relief)
High point nearbyHulse Hill, 1,410 ft, 11 mi west
Rock at the surfaceMaxville Limestone; Rushville, Logan, and Cuyhoga Formations, Undivided
Its ageDevonian to Carboniferous, 324 to 422 million years old
5

South Mount Vernon’s year

South Mount Vernon has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 17° in January. About 44 inches of rain fall in a normal year.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 44.2 in
July, average83° / 61° · high / low, the warmest month
January, average34° / 17° · high / low, the coldest month
Rain a year44.2 in · wettest months: June and May
Hottest on record100°F · July 14, 1954
Coldest on record−29°F · January 19, 1994
Wettest day on record5.18 in · September 14, 1979
Snowiest day on record15.0 in · February 6, 2026
90° days a year9 · none reach 100°
Nights at or below 32°128 · and 40 days that stay below freezing
Climate typeHot-summer humid continental · Köppen Dfa
1Freeze season · from the first fall freeze, about Oct. 17, to the last in spring, about April 27 (median dates)
2Lows below freezing · Nov. 11 to March 31; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 South Mount Vernon normally reaches 51° and falls to 32°. The record high is 71°, in 1989; the record low 4°, in 2019. The most rain on this date, 1.20 in, fell in 1972.

Normals 1991–2020 and records since 1950 at Centerburg 2 SE, 10 miles southwest, 180 ft higher. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 1,930 mito the Gulf of AmericaKokosing → Walhonding → Muskingum → Ohio → Mississippi

A raindrop that lands in South Mount Vernon reaches the Gulf of America by way of the Kokosing, the Walhonding, the Muskingum, the Ohio and the Mississippi: about 1,930 river miles.

970 miles of the trip are on the Mississippi.