Portsmouth weather in October

In October, Portsmouth sees average daytime highs of 58°F and overnight lows near 47°F, with 4.4 in of precipitation across 9.9 wet days and about 10.8 hours of daylight. It is the 6th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 63°F in the first days to 54°F by the end. The sky is clear or mostly clear about 38% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 30 min at the start of October to 10 h 06 min by month's end. Set against the rest of the year, October is Portsmouth's 3rd-clearest and 6th-windiest month. For the whole year in context, see Portsmouth's year-round climate.

Daytime high
58°
6th warmest
Overnight low
47°
7th coldest
Precipitation
4.4 in
9.9 wet days
Daylight
10 h 48 min
6:04 AM – 4:52 PM
Cloud cover
55%
3rd clearest
Wind
10 mph
6th windiest
Solar energy
2.93 kWh/m²
Travel score
4.5
out of 10

Portsmouth is city in Rockingham County, New Hampshire, United States.

Density
494/km²
people per km²
Founded
1630

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 63°F in the first days to 54°F by the end.

A typical October day in Portsmouth reaches about 58°F in the afternoon and slips back to 47°F overnight — a 11°F spread between the day's warmth and the night's chill. On most days the high lands between 51°F and 66°F. Set against its neighbours, October runs about 10°F cooler than September and about 10°F warmer than November.

30°40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
16352
26352
36352
46251
56251
66251
76150
86150
96150
106049
116049
126049
135948
145948
155848
165847
175847
185847
195746
205746
215646
225646
235645
245545
255545
265544
275544
285444
295443
305343
315343

How October really feels in Portsmouth

Once humidity and wind are folded in, October averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

October sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Portsmouth weather by month

How October compares with the rest of the year at a glance. October is the 6th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan34° / 22°3.69.96.79.20.0
Feb35° / 23°3.49.1610.20.0
Mar41° / 30°4.511.25.211.60.2
Apr51° / 40°4.210.61.313.12.4
May60° / 49°3.310.5014.44.7
Jun69° / 58°3.610.6015.16.3
Jul75° / 65°3.110.6014.96.9
Aug74° / 64°3.28.8013.87.2
Sep68° / 57°3.48.5012.36.6
Oct58° / 47°4.49.90.210.84.5
Nov48° / 37°3.89.71.29.51.8
Dec39° / 28°4.610.84.98.90.1

Cloud cover in October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 38% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 15% of October, with mostly cloudy or overcast conditions the remaining 47%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15446
25446
35545
45545
55545
65644
75644
85644
95644
105644
115644
125644
135545
145545
155545
165545
175446
185347
195347
205347
215347
225248
235149
245149
255050
265050
274951
284951
294852
304951
314852

Chance of precipitation in October

Any precipitation

Portsmouth gets around 4.4 in of rain and snow over 9.9 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 32% and peaks near 33% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%151015202531
Rain chance (%)
130
231
331
431
532
632
732
832
932
1032
1131
1231
1331
1431
1531
1631
1731
1831
1931
2031
2131
2232
2332
2432
2532
2632
2733
2833
2933
3032
3132

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

Most of October feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, October lands in the dry band about 88% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1702082
2731872
3751762
4781651
5791551
6811441
7831331
8841231
9861121
10861121
11871021
1288921
1389821
1490811
1592710
1692710
1793610
1893610
1993610
2093610
2193610
2293610
2393610
2494510
2594510
2694510
2794510
2895410
2995410
3095410
3195410

Wind in October

Winds average 10 mph in October.

Across October, daily wind ranges from about 9 mph on the calmest days to 11 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
19light breeze
29light breeze
39light breeze
49light breeze
59light breeze
610light breeze
710light breeze
810light breeze
910light breeze
1010light breeze
1110light breeze
1210light breeze
1310light breeze
1410light breeze
1510light breeze
1610light breeze
1710light breeze
1810light breeze
1910light breeze
2010light breeze
2110light breeze
2210light breeze
2310light breeze
2410light breeze
2510light breeze
2610light breeze
2711light breeze
2811light breeze
2911light breeze
3011light breeze
3111light breeze

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 30 min at the start of October to 10 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over October. Sunrise moves from 5:46 AM to 6:23 AM, and sunset from 5:18 PM to 4:30 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.55:465:18
211.55:475:16
311.45:485:14
411.45:495:13
511.35:515:11
611.35:525:09
711.25:535:07
811.25:545:06
911.15:555:04
1011.15:575:02
1111.05:585:00
1211.05:594:59
1310.96:004:57
1410.96:024:55
1510.86:034:54
1610.86:044:52
1710.86:054:50
1810.76:074:49
1910.76:084:47
2010.66:094:46
2110.66:104:44
2210.56:124:43
2310.56:134:41
2410.46:144:40
2510.46:154:38
2610.36:174:37
2710.36:184:35
2810.26:194:34
2910.26:214:33
3010.26:224:31
3110.16:234:30

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 2.93 kWh/m².

For context, solar energy here swings from a low near 1.54 kWh/m² to a high of 6.11 kWh/m² in July across the year — October's 2.93 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.5Moderate
43.4Moderate
53.4Moderate
63.3Moderate
73.3Moderate
83.3Moderate
93.2Moderate
103.2Moderate
113.1Moderate
123.1Moderate
133.1Moderate
143.0Moderate
153.0Moderate
162.9Moderate
172.9Moderate
182.9Moderate
192.8Moderate
202.8Moderate
212.7Moderate
222.7Moderate
232.7Moderate
242.6Moderate
252.6Moderate
262.5Moderate
272.5Moderate
282.5Moderate
292.4Moderate
302.4Moderate
312.4Moderate
Planning a trip in October

Hazard calendar for Portsmouth

In seasonPeak

In October, Portsmouth sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Portsmouth sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is October a good time to visit Portsmouth?

Our two travel scores rate October for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

4.5
Sightseeing
6th-best month of the year
0.4
Beach & pool
6th-best month of the year

October is a reasonable time to visit Portsmouth for sightseeing.

What to pack for Portsmouth in October

From October's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In October, Portsmouth sees daytime highs around 58°F and nights near 47°F. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Portsmouth in October

The nearest coast averages about 55°F in October — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 65°F and coldest in March near 38°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

40°50°60°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°F)Comfort
Jan42Bracing
Feb39Bracing
Mar38Bracing
Apr42Bracing
May49Bracing
Jun57Bracing
Jul63Cool
Aug65Cool
Sep62Cool
Oct55Bracing
Nov49Bracing
Dec45Bracing

UV index in Portsmouth in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Portsmouth peaks around July 10 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 23 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighHighModerateModerateLowJul 10UV 7Dec 23UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5High
May7High
Jun7High
Jul7Very high
Aug4Moderate
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low
Location & terrain

Where is Portsmouth?

Portsmouth sits at 43.1°N, 70.8°W, 20 ft above sea level, in United States. The nearest listed city is Dover, 9.9 mi away.

Topography around Portsmouth

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Portsmouth.

Within 2 miles, the terrain around Portsmouth has only modest variations in elevation — a maximum elevation change of 161 ft around an average of 39 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 430 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,454 ft.

The land around Portsmouth is covered by trees (45%), water (22%) and artificial surfaces (21%) within 2 miles, trees (49%) and water (36%) within 10 miles, and trees (61%) and water (32%) within 50 miles.

2 miles
161 ft
10 miles
430 ft
50 miles
2,454 ft
treesgrasslandartificial surfaceswaterwetland
October weather nearby: Dover 9.9 mi · Amesbury 17 mi · Rochester 19 mi · Newburyport 19 mi · Sanford 25 mi · Haverhill 26 mi · Salem 30 mi · Derry Village 31 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Portsmouth (43.077°, -70.7577°, elevation 20 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).