Portsmouth, IA Weather Forecast
Local 7-day forecast
Slight Chance Snow Showers then Sunny
Track current conditions, temperature changes, wind, and the full daily outlook for Portsmouth, IA in one place.
A slight chance of snow showers before 7am. Sunny, with a high near 52. Northwest wind 14 to 20 mph, with gusts as high as 29 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: Apr 16, 2026 8:22 AM CDT.
The active forecast window currently covers Apr 18 to Apr 22, 2026 for Portsmouth, IA.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Apr 18 to Apr 22, 2026
- Latest sync
- Apr 16, 2026 8:22 AM CDT
- Forecast office
- OAX
- Source
- NOAA / NWS
Daily Outlook
This Week in Portsmouth
Tuesday looks like the warmest upcoming period in Portsmouth at 75 degrees F.
Saturday Night is the coolest period ahead with temperatures near 29 degrees F.
The strongest winds are forecast for Saturday at about 14 to 20 mph NW.
Precipitation is mentioned in 3 upcoming forecast periods.
Forecast Details
- Last updated
- Apr 16, 2026 8:22 AM CDT
- Coverage
- 5 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
Mostly clear, with a low around 29. West northwest wind 2 to 17 mph, with gusts as high as 25 mph.
Sunny, with a high near 63. West wind 3 to 9 mph.
Mostly clear, with a low around 38. East wind 6 to 10 mph, with gusts as high as 17 mph.
Sunny, with a high near 72. South southeast wind 10 to 20 mph, with gusts as high as 28 mph.
Mostly clear, with a low around 49. South wind 13 to 17 mph, with gusts as high as 24 mph.
Sunny, with a high near 75. South southwest wind 12 to 16 mph, with gusts as high as 23 mph.
Mostly clear, with a low around 49. South wind 10 to 14 mph, with gusts as high as 20 mph.
A slight chance of rain showers after 1pm. Mostly sunny, with a high near 74. South southeast wind 10 to 17 mph, with gusts as high as 25 mph.
A slight chance of rain showers before 7pm, then a chance of showers and thunderstorms. Partly cloudy, with a low around 52. Southeast wind 13 to 16 mph, with gusts as high as 23 mph.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Saturday
Apr 18
|
Slight Chance Snow Showers then Sunny
|
52°F |
14 to 20 mph
NW
|
|
Saturday Night
Apr 18
|
Mostly Clear
|
29°F |
2 to 17 mph
WNW
|
|
Sunday
Apr 19
|
Sunny
|
63°F |
3 to 9 mph
W
|
|
Sunday Night
Apr 19
|
Mostly Clear
|
38°F |
6 to 10 mph
E
|
|
Monday
Apr 20
|
Sunny
|
72°F |
10 to 20 mph
SSE
|
|
Monday Night
Apr 20
|
Mostly Clear
|
49°F |
13 to 17 mph
S
|
|
Tuesday
Apr 21
|
Sunny
|
75°F |
12 to 16 mph
SSW
|
|
Tuesday Night
Apr 21
|
Mostly Clear
|
49°F |
10 to 14 mph
S
|
|
Wednesday
Apr 22
|
Mostly Sunny then Slight Chance Rain Showers
|
74°F |
10 to 17 mph
SSE
|
|
Wednesday Night
Apr 22
|
Chance Showers And Thunderstorms
|
52°F |
13 to 16 mph
SE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Portsmouth.