Portsmouth · first 14 days — live forecast · rest of month — climate corridor
🗺️ 14-day forecast map
Portsmouth & neighbors — hit play
Every city on the map carries real forecast data from the same models as its city page, refreshed several times a day. The icon is the day's overall look; the number is the afternoon high.
Next 14 days at a glance
from the model forecast
Hottest day
80°
Thu, Sep 10
Coldest night
47°
Sat, Sep 12
Days with precip
3 / 14
of 14 forecast days
Nicest day
Mon, Sep 7
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 5 – Sun 6 Sep
71° 55°
51% precip chance
Sat 12 – Sun 13 Sep
74° 47°
8% precip chance
Sat 19 – Sun 20 Sep
72° 56°
typical range
Sat 26 – Sun 27 Sep
71° 58°
typical range
30 days — Portsmouth
14 forecast + 16 climatology
Sat · Today Partly cloudy
71°60°0.2 mm⌄
Wind14 mph NE
Gusts20 mph
UV index4 – Moderate
Precip chance24%
Sunrise06:11
Sunset19:11
Sun · Tomorrow Mostly cloudy
68°55°0.8 mm⌄
Wind11 mph NE
Gusts21 mph
UV index5 – Moderate
Precip chance51%
Sunrise06:13
Sunset19:09
Monday 7/9 Sunny
74°55°4%⌄
Wind8 mph W
Gusts15 mph
UV index6 – Moderate
Precip chance4%
Sunrise06:14
Sunset19:08
Tuesday 8/9 Mostly cloudy
71°60°0.4 mm⌄
Wind13 mph E
Gusts28 mph
UV index6 – Moderate
Precip chance39%
Sunrise06:15
Sunset19:06
Wednesday 9/9 Mostly cloudy
73°58°0.8 mm⌄
Wind15 mph SW
Gusts36 mph
UV index6 – High
Precip chance62%
Sunrise06:16
Sunset19:04
Thursday 10/9 Mostly cloudy
80°69°0.7 mm⌄
Wind17 mph SW
Gusts41 mph
UV index6 – High
Precip chance48%
Sunrise06:17
Sunset19:02
Friday 11/9 Sunny
69°57°0.3 mm⌄
Wind13 mph NW
Gusts24 mph
UV index6 – High
Precip chance36%
Sunrise06:18
Sunset19:00
Saturday 12/9 Sunny
61°47°3%⌄
Wind11 mph SE
Gusts26 mph
UV index5 – Moderate
Precip chance3%
Sunrise06:19
Sunset18:59
Sunday 13/9 Sunny
74°53°8%⌄
Wind18 mph SW
Gusts28 mph
UV index6 – High
Precip chance8%
Sunrise06:20
Sunset18:57
Monday 14/9 Sunny
69°56°17%⌄
Wind17 mph SE
Gusts27 mph
UV index5 – Moderate
Precip chance17%
Sunrise06:21
Sunset18:55
Tuesday 15/9 Sunny
61°53°7%⌄
Wind11 mph SE
Gusts16 mph
UV index5 – Moderate
Precip chance7%
Sunrise06:22
Sunset18:53
Wednesday 16/9 Mostly cloudy
64°59°21%⌄
Wind14 mph NE
Gusts21 mph
UV index5 – Moderate
Precip chance21%
Sunrise06:23
Sunset18:51
Thursday 17/9 Fog
68°60°0.6 mm⌄
Wind11 mph E
Gusts21 mph
UV index5 – Moderate
Precip chance60%
Sunrise06:25
Sunset18:50
Friday 18/9 Showers
61°52°10.7 mm⌄
Wind17 mph NE
Gusts22 mph
UV index4 – Moderate
Precip chance90%
Sunrise06:26
Sunset18:48
Saturday 19/9 Rain (climatological)
67°56°2.6 mm⌄
Day≈61–72°
Night≈50–61°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 20/9 Partly cloudy (climatological)
72°58°20%⌄
Day≈66–77°
Night≈53–64°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 21/9 Partly cloudy (climatological)
71°58°20%⌄
Day≈65–76°
Night≈53–63°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 22/9 Light rain (climatological)
69°57°1.7 mm⌄
Day≈64–75°
Night≈52–62°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 23/9 Partly cloudy (climatological)
69°57°20%⌄
Day≈64–74°
Night≈52–62°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 24/9 Partly cloudy (climatological)
63°53°20%⌄
Day≈57–68°
Night≈48–58°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 25/9 Rain (climatological)
63°53°4.1 mm⌄
Day≈58–69°
Night≈48–59°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 26/9 Partly cloudy (climatological)
71°58°20%⌄
Day≈65–76°
Night≈53–63°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 27/9 Partly cloudy (climatological)
71°58°20%⌄
Day≈65–76°
Night≈52–63°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 28/9 Light rain (climatological)
73°59°2.0 mm⌄
Day≈67–78°
Night≈54–65°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 29/9 Partly cloudy (climatological)
72°59°20%⌄
Day≈66–77°
Night≈53–64°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 30/9 Partly cloudy (climatological)
66°55°20%⌄
Day≈60–71°
Night≈49–60°
Precip≈1.2 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 1/10 Rain (climatological)
53°43°2.1 mm⌄
Day≈48–59°
Night≈38–49°
Precip≈1.2 in / October
(climatological)Typical range for these dates · 1991–2020
Friday 2/10 Partly cloudy (climatological)
51°42°20%⌄
Day≈46–56°
Night≈37–47°
Precip≈1.2 in / October
(climatological)Typical range for these dates · 1991–2020
Saturday 3/10 Partly cloudy (climatological)
56°45°20%⌄
Day≈51–61°
Night≈39–50°
Precip≈1.2 in / October
(climatological)Typical range for these dates · 1991–2020
Sunday 4/10 Rain (climatological)
58°46°2.4 mm⌄
Day≈53–64°
Night≈41–52°
Precip≈1.2 in / October
(climatological)Typical range for these dates · 1991–2020
How does a 30-day outlook work?
The first 14 days are a live model forecast. The back half of the month shows the typical range for those dates — useful for planning, not a literal prediction.
First 14 days: a real forecast, blended from NBM, ECMWF and GFS runs. Trust it most inside three days; by the second week treat it as a lean, not a promise.
Rest of the month: past day 14 we stop pretending to forecast and switch to the climate corridor — the range those dates have produced over three decades computed directly for Portsmouth, with mild week-to-week wiggle.
Good question for this page: "Is late August usually humid in Chicago?" Bad question: "Do I need an umbrella on the 29th?" — three weeks out no one knows, and that's the honest answer.