Portsmouth, IA Weather Forecast & Alerts

Current conditions, 5-day forecast, and active NWS weather alerts for Portsmouth, IA.

0 Active Alerts for Portsmouth

✅
No active weather alerts for Portsmouth at this time.
Subscribe to receive instant notifications when alerts are issued.

Current Conditions — Portsmouth, IA

DENISON (KDNS)

Haze

46.4 F
Humidity:71%
Wind Speed: 10.3 mph
Barometer:30.07 in
Dewpoint:37.4 F
Visibility:5.00 mi
Precip:--
Heat Index:NA
Wind Chill:41.5 F
May 1 2026, 09:15 AM CDT
Severe Weather Alerts
Severe Weather
 		Daily Weather Forecast
Daily Forecast
 		Observation Alert Monitoring
Observations
 		Storm Report Monitoring
Storm Reports

5-Day Forecast — Portsmouth, IA

Friday

High 57 °F
Partly Sunny
Friday
Night
Low 32 °F
Mostly Clear
Saturday

High 66 °F
Mostly Sunny
Saturday
Night
Low 46 °F
Partly Cloudy
Sunday

High 73 °F
Mostly Cloudy
Sunday
Night
Low 46 °F
Partly Cloudy
Monday

High 77 °F
Mostly Sunny
Monday
Night
Low 42 °F
Slight Chance of Rain
Tuesday

High 62 °F
Chance of Rain Showers

Detailed Forecast — Portsmouth, IA

Friday
Partly Sunny. High near 57°F. Wind 8 to 14 mph, with gusts as high as 21 mph.
Friday Night
Mostly Clear. Low around 32°F. Wind 0 to 8 mph, with gusts as high as 13 mph.
Saturday
Mostly Sunny. High near 66°F. Wind 1 to 7 mph, with gusts as high as 13 mph.
Saturday Night
Partly Cloudy. Low around 46°F. Wind 6 to 10 mph, with gusts as high as 17 mph.
Sunday
Mostly Cloudy. High near 73°F. Wind 6 to 10 mph, with gusts as high as 15 mph.
Sunday Night
Partly Cloudy. Low around 46°F. Wind around 2 mph, with gusts as high as 6 mph.
Monday
Mostly Sunny. High near 77°F. Wind 13 to 14 mph, with gusts as high as 20 mph.
Monday Night
Slight Chance of Rain. Low around 42°F. Wind around 8 mph, with gusts as high as 15 mph.
Tuesday
Chance of Rain Showers. High near 62°F. Wind 12 to 14 mph, with gusts as high as 20 mph.
Tuesday Night
Isolated T-storm. Low around 37°F. Wind around 3 mph, with gusts as high as 9 mph.
Wednesday
Mostly Cloudy. High near 59°F. Wind 10 to 13 mph, with gusts as high as 18 mph.
Wednesday Night
Mostly Clear. Low around 37°F. Wind around 2 mph, with gusts as high as 5 mph.
Thursday
Mostly Sunny. High near 66°F. Wind 6 to 10 mph, with gusts as high as 15 mph.
IA Radar
Current Radar • IA
Day 1 Outlook • May 1, 2026

Observation History — Portsmouth, IA

Time Wind
(mph)		 Vis
(mi)		 Weather Precip (in) Temperature (F) Relative
Humidity		 Wind
Chill
(F)		 Heat
Index
(F)		 Pressure
Air Dwpt altimeter
(in)		 sea level
(mb)
09:15 AM CDT 10.3 5.00 Haze -- 46.4 37.4 71% 41.5 NA 30.07 1018.3
08:55 AM CDT 8.1 6.00 Haze -- 44.6 39.2 81% 40.1 NA 30.07 1018.3
08:35 AM CDT 5.8 5.00 Haze -- 44.6 37.4 76% 41.4 NA 30.06 1018.0
08:15 AM CDT 5.00 Haze -- NULL % NA NA M
07:55 AM CDT 0.0 5.00 Haze -- 41.0 35.6 81% NA NA 30.06 1018.0
07:35 AM CDT 0.0 6.00 Fog/Mist -- 39.2 37.4 93% NA NA 30.06 1018.0
07:15 AM CDT 0.0 10.00 Clear -- 37.4 37.4 100% NA NA 30.06 1018.0
06:55 AM CDT 0.0 10.00 Clear -- 35.6 35.6 100% NA NA 30.05 1017.6
06:35 AM CDT 4.7 6.00 Fog/Mist -- 35.6 35.6 100% 31.6 NA 30.04 1017.3
06:15 AM CDT SW 4.7 7.00 NULL -- 35.6 35.6 100% 31.6 NA 30.04 1017.3
05:55 AM CDT 3.4 6.00 Fog/Mist -- 35.6 35.6 100% 32.9 NA 30.04 1017.3
05:35 AM CDT W 4.7 6.00 Fog/Mist -- 35.6 35.6 100% 31.6 NA 30.04 1017.3
05:15 AM CDT W 3.4 6.00 Fog/Mist -- 35.6 35.6 100% 32.9 NA 30.04 1017.3
04:55 AM CDT 0.0 6.00 Fog/Mist -- 35.6 35.6 100% NA NA 30.04 1017.3
04:35 AM CDT 0.0 7.00 Cloudy -- 35.6 35.6 100% NA NA 30.04 1017.3
04:15 AM CDT 0.0 10.00 Mostly Cloudy -- 37.4 37.4 100% NA NA 30.05 1017.6
03:55 AM CDT 0.0 7.00 Clear -- 37.4 35.6 93% NA NA 30.05 1017.6
03:35 AM CDT 0.0 10.00 Partly Cloudy -- NULL % NA NA 30.05 1017.6
03:15 AM CDT 0.0 10.00 Mostly Cloudy -- 35.6 35.6 100% NA NA 30.05 1017.6
02:55 AM CDT SW 3.4 7.00 Partly Cloudy -- 39.2 33.8 81% 37.0 NA 30.05 1017.6
02:35 AM CDT 0.0 7.00 Mostly Clear -- 37.4 35.6 93% NA NA 30.06 1018.0
02:15 AM CDT 0.0 7.00 Partly Cloudy -- 39.2 37.4 93% NA NA 30.06 1018.0
01:55 AM CDT 0.0 7.00 NULL -- 39.2 39.2 100% NA NA 30.07 1018.3
01:15 AM CDT 0.0 7.00 Cloudy -- 37.4 37.4 100% NA NA 30.08 1018.6

Regional Weather Observation

DENISON (KDNS)

Haze
46.4 F

HARLAN MUNI (KHNR)

Clear
48.2 F

OMAHA/EPPLEY (KOMA)

Clear
48.2 F

TEKAMAH (KTQE)

Clear
48.2 F

COUNCIL BLUFFS (KCBF)

Clear
48.2 F

ATLANTIC (KAIO)

Clear
50.0 F
🔔    Sign-up to receive daily weather forecasts by email or text - subscribe