Portsmouth, New Hampshire Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Portsmouth weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Drizzle23%0.05″90°73°—
- SundayJul 5Overcast——78°64°-12°
- MondayJul 6Overcast34%—70°61°-8°
- TuesdayJul 7Light Drizzle51%0.01″65°59°-5°
- WednesdayJul 8Overcast25%—70°53°+5°
- ThursdayJul 9Overcast18%—91°60°+21°
- FridayJul 10Light Drizzle47%—76°66°-15°
AQI 39 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 8.8 µg/m³, PM10 at 9.5 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 46. Overcast through the UV peak window (cloud cover ~68%) — afternoon ozone should stay flat.
- Present
- AQI 46
- UV peak
- 8.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 25
PM × Wind × Precip
PM2.5 at 8.8 µg/m³, PM10 at 9.5 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.93
- Wind
- breezy
- Recent rain
- 0h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 10:42 PM
- Moonset
- 9:42 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Portsmouth at a glance
- Today vs. normal: 20°F above the seasonal normal for this latitude
- Last frost: May 4 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 03801
16-Day Forecast — Portsmouth
- Sat90°73°23%
- Sun78°64°1%
- Mon70°61°34%
- Tue65°59°51%
- Wed70°53°25%
- Thu91°60°18%
- Fri76°66°47%
- Sat71°63°26%
- Sun69°60°15%
- Mon66°62°31%
- Tue66°63°29%
- Wed75°64°35%
- Thu86°66°23%
- Fri87°68°27%
- Sat89°68°26%
- Sun83°59°23%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Portsmouth
Right now in the garden
Peak growing season
As of July 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Portsmouth
SPC includes Portsmouth in the general thunderstorm area today — no severe risk, but storms are possible.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
ZIP codes in Portsmouth
- 03801
- 03802
- 03803
- 03804