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
28°
Thu, Sep 10
Coldest night
11°
Sat, Sep 12
Days with precip
6 / 14
of 14 forecast days
Nicest day
Fri, Sep 11
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 12 – Sun 13 Sep
25° 11°
15% precip chance
Sat 19 – Sun 20 Sep
21° 11°
typical range
Sat 26 – Sun 27 Sep
23° 12°
typical range
Sat 3 – Sun 4 Oct
15° 6°
typical range
30 days — Portsmouth
14 forecast + 16 climatology
Sun · Today Mostly cloudy
21°13°5.0 mm⌄
Wind11 mph N
Gusts21 mph
UV index6 – Moderate
Precip chance77%
Sunrise06:13
Sunset19:09
Mon · Tomorrow Sunny
25°13°4%⌄
Wind9 mph W
Gusts21 mph
UV index6 – Moderate
Precip chance4%
Sunrise06:14
Sunset19:08
Tuesday 8/9 Mostly cloudy
24°16°10%⌄
Wind12 mph W
Gusts26 mph
UV index6 – Moderate
Precip chance10%
Sunrise06:15
Sunset19:06
Wednesday 9/9 Mostly cloudy
22°14°0.9 mm⌄
Wind14 mph SW
Gusts33 mph
UV index5 – Moderate
Precip chance63%
Sunrise06:16
Sunset19:04
Thursday 10/9 Mostly cloudy
28°19°4.6 mm⌄
Wind17 mph SW
Gusts37 mph
UV index6 – Moderate
Precip chance81%
Sunrise06:17
Sunset19:02
Friday 11/9 Sunny
20°13°5%⌄
Wind16 mph NW
Gusts24 mph
UV index6 – High
Precip chance5%
Sunrise06:18
Sunset19:00
Saturday 12/9 Mostly cloudy
21°11°11%⌄
Wind13 mph S
Gusts23 mph
UV index5 – Moderate
Precip chance11%
Sunrise06:19
Sunset18:59
Sunday 13/9 Mostly cloudy
25°14°15%⌄
Wind10 mph SW
Gusts23 mph
UV index6 – High
Precip chance15%
Sunrise06:20
Sunset18:57
Monday 14/9 Mostly cloudy
26°19°1.0 mm⌄
Wind10 mph SW
Gusts25 mph
UV index6 – High
Precip chance60%
Sunrise06:21
Sunset18:55
Tuesday 15/9 Showers
18°14°6.0 mm⌄
Wind17 mph NE
Gusts23 mph
UV index4 – Moderate
Precip chance89%
Sunrise06:22
Sunset18:53
Wednesday 16/9 Showers
22°15°19.9 mm⌄
Wind7 mph S
Gusts18 mph
UV index5 – Moderate
Precip chance94%
Sunrise06:23
Sunset18:51
Thursday 17/9 Sunny
24°15°0.3 mm⌄
Wind14 mph W
Gusts26 mph
UV index6 – High
Precip chance36%
Sunrise06:25
Sunset18:50
Friday 18/9 Sunny
16°11°7%⌄
Wind9 mph NW
Gusts24 mph
UV index4 – Moderate
Precip chance7%
Sunrise06:26
Sunset18:48
Saturday 19/9 Sunny
16°11°4%⌄
Wind11 mph S
Gusts18 mph
UV index5 – Moderate
Precip chance4%
Sunrise06:27
Sunset18:46
Sunday 20/9 Rain (climatological)
21°13°6.8 mm⌄
Day≈18–24°
Night≈10–16°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 21/9 Partly cloudy (climatological)
24°15°20%⌄
Day≈21–27°
Night≈12–18°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 22/9 Partly cloudy (climatological)
23°15°20%⌄
Day≈20–26°
Night≈12–18°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 23/9 Rain (climatological)
22°14°4.4 mm⌄
Day≈19–25°
Night≈11–17°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 24/9 Partly cloudy (climatological)
22°14°20%⌄
Day≈19–25°
Night≈11–17°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 25/9 Partly cloudy (climatological)
19°12°20%⌄
Day≈16–22°
Night≈9–15°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 26/9 Rain (climatological)
19°12°10.9 mm⌄
Day≈16–22°
Night≈9–15°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 27/9 Partly cloudy (climatological)
23°15°20%⌄
Day≈20–26°
Night≈12–18°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 28/9 Partly cloudy (climatological)
23°15°20%⌄
Day≈20–26°
Night≈12–18°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 29/9 Rain (climatological)
24°15°5.2 mm⌄
Day≈21–27°
Night≈12–18°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 30/9 Partly cloudy (climatological)
24°15°20%⌄
Day≈21–27°
Night≈12–18°
Precip≈3.2 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 1/10 Partly cloudy (climatological)
13°6°20%⌄
Day≈10–16°
Night≈3–9°
Precip≈3.2 in / October
(climatological)Typical range for these dates · 1991–2020
Friday 2/10 Rain (climatological)
13°6°5.5 mm⌄
Day≈10–16°
Night≈3–9°
Precip≈3.2 in / October
(climatological)Typical range for these dates · 1991–2020
Saturday 3/10 Partly cloudy (climatological)
12°6°20%⌄
Day≈9–15°
Night≈3–9°
Precip≈3.2 in / October
(climatological)Typical range for these dates · 1991–2020
Sunday 4/10 Partly cloudy (climatological)
15°7°20%⌄
Day≈12–18°
Night≈4–10°
Precip≈3.2 in / October
(climatological)Typical range for these dates · 1991–2020
Monday 5/10 Rain (climatological)
16°8°6.3 mm⌄
Day≈13–19°
Night≈5–11°
Precip≈3.2 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.