Portsmouth, IA Weather Forecast
Local 7-day forecast
Sunny then Isolated Rain Showers
Track current conditions, temperature changes, wind, and the full daily outlook for Portsmouth, IA in one place.
Isolated rain showers after 3pm. Sunny, with a high near 93. West wind around 3 mph. Chance of precipitation is 20%.
Local Weather Overview
This forecast page for Portsmouth, IA is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Jul 17, 2026 3:42 PM CDT.
The active forecast window currently covers Jul 18 to Jul 23, 2026 for Portsmouth, IA.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Jul 18 to Jul 23, 2026
- Latest sync
- Jul 17, 2026 3:42 PM CDT
- Forecast office
- OAX
- Source
- NOAA / NWS
Daily Outlook
This Week in Portsmouth
Monday looks like the warmest upcoming period in Portsmouth at 99 degrees F.
Tuesday Night is the coolest period ahead with temperatures near 60 degrees F.
The strongest winds are forecast for Tuesday at about 9 to 15 mph N.
Precipitation is mentioned in 5 upcoming forecast periods.
Forecast Details
- Last updated
- Jul 17, 2026 3:42 PM CDT
- Coverage
- 6 days
- Time zone
- America/Chicago
- Forecast office
- OAX
- Radar station
- KOAX
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
Isolated rain showers before 7pm. Mostly clear, with a low around 69. East northeast wind around 7 mph. Chance of precipitation is 20%.
Sunny, with a high near 93. Southeast wind around 7 mph.
Mostly clear, with a low around 74. South wind around 8 mph.
Sunny, with a high near 99. South southwest wind 6 to 10 mph, with gusts as high as 16 mph.
Mostly clear, with a low around 70. Northwest wind 6 to 9 mph, with gusts as high as 16 mph.
Sunny, with a high near 88. North wind 9 to 15 mph, with gusts as high as 23 mph.
Mostly clear, with a low around 60. North northeast wind 2 to 12 mph, with gusts as high as 18 mph.
Mostly sunny, with a high near 83. North northeast wind 2 to 6 mph.
A slight chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 62. East southeast wind around 5 mph.
A slight chance of showers and thunderstorms before 1pm. Partly sunny, with a high near 83. South wind 3 to 8 mph.
A slight chance of showers and thunderstorms after 7pm. Partly cloudy, with a low around 61. South southeast wind 2 to 7 mph.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Saturday
Jul 18
|
Sunny then Isolated Rain Showers
|
93°F |
3 mph
W
|
|
Saturday Night
Jul 18
|
Isolated Rain Showers then Mostly Clear
|
69°F |
7 mph
ENE
|
|
Sunday
Jul 19
|
Sunny
|
93°F |
7 mph
SE
|
|
Sunday Night
Jul 19
|
Mostly Clear
|
74°F |
8 mph
S
|
|
Monday
Jul 20
|
Sunny
|
99°F |
6 to 10 mph
SSW
|
|
Monday Night
Jul 20
|
Mostly Clear
|
70°F |
6 to 9 mph
NW
|
|
Tuesday
Jul 21
|
Sunny
|
88°F |
9 to 15 mph
N
|
|
Tuesday Night
Jul 21
|
Mostly Clear
|
60°F |
2 to 12 mph
NNE
|
|
Wednesday
Jul 22
|
Mostly Sunny
|
83°F |
2 to 6 mph
NNE
|
|
Wednesday Night
Jul 22
|
Partly Cloudy then Slight Chance Showers And Thunderstorms
|
62°F |
5 mph
ESE
|
|
Thursday
Jul 23
|
Slight Chance Showers And Thunderstorms
|
83°F |
3 to 8 mph
S
|
|
Thursday Night
Jul 23
|
Slight Chance Showers And Thunderstorms
|
61°F |
2 to 7 mph
SSE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Portsmouth.