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Shaded-relief atlas plate of Portsmouth, Michigan: rivers, roads, the city limits and where the water drains.
MICHIGAN · BAY COUNTY

Portsmouth

3,173 people, 600 ft above sea level in Bay County.

600 ftElevation, city center
3,173People, 2024 estimate
20 sq miLand area
Sunny 77°
Sunny now Dew point 51° · SSW 12 mph · high 77°
City of Portsmouth River Interstate 2 miles
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The Portsmouth 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 Portsmouth

NWS forecast and National Blend of Models · updated 4:00 PM EDT
RIGHT NOW MBS International Airport (KMBS) · 3:53 PM
Sunny
77° Sunny Feels like 77° · high of 77° near 4 PM
WindSSW 12 mphgusts 17
Humidity40%rising to 81% by morning
Pressure30.00 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 51° · Dry64° by Thursday: more humid
DryComfortableStickyMuggyOppressive
NEXT RAIN
Mostly cloudy
Tomorrow, about 1 PMin about 20 hours · 34% chance · rain
LIKELY AMOUNT0.2–1.1 inmost likely 0.5; 1 in 10 over 1.5
LAST RAINSept. 200.01 in · 9 dry days
ALERTS & OUTLOOKS
No watches or warnings for Bay County
NWS Detroit/Pontiac and the Storm Prediction Center · checked 4:51 PM
SUN & MOON
↑ 7:30 AM7:20 PM ↓
11 h 50 m of daylight, 3 minutes less than yesterday
Waning gibbous, 89% lit. The Harvest Moon was full Saturday.
AIR & POLLEN
32
GOODAir quality index · ozone
Tomorrow: None, moderate. No pollen source yet.

The next three days, hour by hour

Sky: clear, cloudy, night Rain likely National Blend of Models
TUESDAY, SEPT. 29
WEDNESDAY, SEPT. 30
THURSDAY, OCT. 1
FRIDAY, OCT. 2
4p
7p
10p
1a
4a
7a
10a
1p
4p
7p
10p
1a
4a
7a
10a
1p
4p
7p
10p
1a
4a
7a
10a
1p
mostly sunny
partly cloudy night
partly cloudy night
mostly cloudy night
mostly cloudy night
mostly cloudy day
mostly cloudy day
rain
mostly cloudy day
rain
rain
rain
rain
rain
rain
rain
rain
rain
rain
rain
rain
rain
mostly cloudy day
partly cloudy day
TEMPERATURE °F
77°
59°
66°
62°
69°
51°
CHANCE OF RAIN
79% · 1.23 in Thursday afternoon 50%
WIND, MPH
9
7
8
8
9
9
10
13
13
13
12
9
9
8
10
10
8
7
7
8
8
7
9
10
HOW IT FEELS · DEW POINT
Comfortable: dew points 50 to 64° ↑ The front passes Drier: 45° by Friday

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 68° / 47°
TUE Sept. 29 Mostly sunny Mostly sunny
77° 59°
0% rain — SW 9 A
WED Sept. 30 Showers likely Showers likely
70° 62°
60% rain 0.2–1.1″ SSW 11, gusts 25 C
THU Oct. 1 Showers likely Showers likely
71° 51°
80% rain 0.6–1.7″ SW 9 C
FRI Oct. 2 Mostly sunny Mostly sunny
66° 39°
10% rain — NNW 9 B
SAT Oct. 3 Partly cloudy Partly cloudy
63° 42°
0% rain — E 3 B
SUN Oct. 4 Mostly sunny Mostly sunny
66° 39°
10% rain — NW 10 B
MON Oct. 5 Mostly sunny Mostly sunny
60° 36°
0% rain — NNW 8 C
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 Portsmouth about 5,000 feet above the ground was over the northern Rockies three days ago, and over the Great Lakes a day ago, about 1,670 miles back along its path. It rose from near the ground on the way. Near the ground the air came from the Great Lakes; at 10,000 feet, from the California coast. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.

MILE7
ON THE NETWORK

Around Portsmouth on the Forecast Network

Neighboring plates

Saginaw MI · 11 MI 11 miles southwest Flint MI · 38 MI 38 miles south Detroit MI · 89 MI 89 miles southeast Grand Rapids MI · 101 MI 101 miles southwest Toledo OH · 131 MI 131 miles south Cleveland OH · 181 MI 181 miles southeast
FORECASTCITY
Atlas plate of Portsmouth, Michigan. Explore the plate
MICHIGAN · BAY

Portsmouth

3,173 people, 600 ft above sea level in Bay County.

600 ftElevation
3,173People
20 sq miLand
Sunny 77°
SunnyDew point 51°
1

Today in Portsmouth

NEXT 15 HOURS
Now mostly sunny 77° 0%
7p mostly clear night 72° 0%
10p partly cloudy night 63° 0%
1a mostly cloudy night 60° 1%
4a mostly cloudy night 60° 4%
7a mostly cloudy night 59° 4%
Mostly cloudy
NEXT RAINTomorrow about 1 PM · 34%
→
Tue0%
Mostly sunny Mostly sunny
59
77
A
Wed60%
Showers likely Showers likely
62
70
C
Thu80%
Showers likely Showers likely
51
71
C
Fri10%
Mostly sunny Mostly sunny
39
66
B
Sat0%
Partly cloudy Partly cloudy
42
63
B
Sun10%
Mostly sunny Mostly sunny
39
66
B
Mon0%
Mostly sunny Mostly sunny
36
60
C
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
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