Climate and average weather in Dover

In Dover, the summers are warm, showery, and partly cloudy and the winters are very cold, snowy, and partly cloudy.

Best: late May to early October

Over the course of the year, the temperature in Dover typically varies from 19°F to 79°F, and is rarely below 2°F or above 89°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Dover for warm-weather activities is from late May to early October.

Hottest
Jul
79°
Coldest
Jan
19°
Wettest
Dec
4.4 in
Driest
May
3.0 in
Rain / yr
43.5 in
118 wet days
Daylight
8.8–15.2 h
shortest–longest
Elevation
62 ft
43.2°N
Clearest
Sep
54% cloud

Dover is county seat city in Strafford County, New Hampshire, United States.

Density
411/km²
people per km²
Founded
1623

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

Dover weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late May to early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Dover, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.0 months, from May 27 to September 24, with daily high temperatures above 68°F. The hottest month of the year in Dover is July, with an average high of 79°F and low of 64°F.

The cool season lasts 3.3 months, from December 5 to March 15, with daily high temperatures below 41°F. The coldest month of the year in Dover is January, with an average low of 19°F and high of 32°F.

Days typically run about 15°F warmer than nights year-round.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan3219
Feb3420
Mar4228
Apr5438
May6448
Jun7458
Jul7964
Aug7862
Sep7155
Oct5945
Nov4835
Dec3826

How hot and cold Dover really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about 7°F (around January 22), with roughly 159 freezing days a year (feels-like at or below 32°F) 68 of them bitterly cold — worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan3232819
Feb3434920
Mar42421928
Apr54543338
May64644548
Jun74745858
Jul79796464
Aug78786262
Sep71715555
Oct59594045
Nov48482835
Dec38381726

Average hourly temperature in Dover

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 79°F, and coldest before dawn in January, near 19°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Dover weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan32° / 19°3.49.36.89.20.0
Feb34° / 20°3.296.110.20.0
Mar42° / 28°4.210.95.411.60.4
Apr54° / 38°4.010.51.413.13.1
May64° / 48°3.010.3014.45.5
Jun74° / 58°3.610.8015.16.5
Jul79° / 64°3.210.7014.96.5
Aug78° / 62°3.39.2013.86.9
Sep71° / 55°3.48.3012.36.9
Oct59° / 45°4.29.50.210.84.8
Nov48° / 35°3.69.21.29.51.8
Dec38° / 26°4.410.45.28.90.0

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Dover gets about 43.5 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.9 months, from around Feb 12 to Aug 10, peaking in April at about 37% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 29.

December is the wettest month by volume, with 4.4 in over about 10 wet days; May is the driest, with 3.0 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetApr 1 · 37%Aug 29 · 26%
Rain on a day (%)Rain days
Jan319
Feb329
Mar3511
Apr3511
May3410
Jun3511
Jul3511
Aug309
Sep278
Oct3010
Nov319
Dec3310

Monthly rainfall

Over a full year, Dover collects about 43.5 in of rain across 118 wet days — roughly 3.6 in in an average month.

It doesn’t fall evenly. December is the wettest month with 4.4 in, while May is the driest at just 3.0 in. The three wettest months alone bring about 29% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec3.43.24.24.03.03.63.23.33.44.23.64.4
Rainfall (in)Rain daysSnow days
Jan3.497
Feb3.296
Mar4.2115
Apr4.0111
May3.0100
Jun3.6110
Jul3.2110
Aug3.390
Sep3.480
Oct4.2100
Nov3.691
Dec4.4105

Snow in Dover

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Dover averages about 26 snowy days a year. Snow season runs roughly Oct 29 to Apr 26 — about 5.9 months.

January is snowiest, with roughly 7 days of snow and an estimated 18 in of snowfall. Over the year that adds up to an estimated 80 in of snow.

0246810JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 14
Snow daysSnowfall (in)
Jan718
Feb621
Mar517
Apr13
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov13
Dec516

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Dover, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around July 2 and lasts for 4.0 months, ending around October 31. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 54% of the time on average.

The cloudier part of the year begins around February 19 and lasts for 4.4 months, ending around July 1. The cloudiest month is May, when it is overcast or mostly cloudy 61% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecAug 28 · 57%May 13 · 38%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan5248
Feb4852
Mar4357
Apr4060
May3961
Jun4357
Jul5050
Aug5347
Sep5446
Oct5248
Nov4852
Dec4654

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 13, brings about 15 h 12 min of light; the shortest, around December 13, only 8 h 48 min — a swing of roughly 6 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.27:194:27
Feb10.26:515:05
Mar11.66:045:42
Apr13.15:086:19
May14.44:266:54
Jun15.14:087:19
Jul14.94:227:16
Aug13.84:546:41
Sep12.35:295:47
Oct10.86:054:52
Nov9.56:454:13
Dec8.97:154:04

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Dover averages about 10 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 7 and 12 days.

The sunnier stretch runs 6.3 months, from around Aug 14 to Feb 21. The sunniest month is October, with roughly 11 sunny days (mixed).

The greyest month is May, down near 7 sunny days — about 37% fewer than the October peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedOct 612 daysMay 177 days
Sunny daysSky
Jan12Mixed
Feb9Mixed
Mar8Mixed
Apr7Gloomy
May7Gloomy
Jun8Gloomy
Jul9Mixed
Aug10Mixed
Sep12Mixed
Oct12Mixed
Nov10Mixed
Dec10Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Dover, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 3.7 months, from around June 6 to September 25. The muggiest month is July, when the air feels humid, muggy or worse about 62% of the time.

The most comfortable stretch runs from around September 26 to June 5, and April is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecApr 7 · 100%Jul 27 · 32%muggyhumiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan1000000
Feb1000000
Mar1000000
Apr991000
May888410
Jun462517101
Jul122629266
Aug172530234
Sep50231791
Oct898210
Nov991000
Dec1000000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Dover is typically light breeze, near 8 mph, and varies little with the seasons.

The windier part of the year lasts 6.5 months, from around Oct 9 to Apr 23. The windiest month is January, averaging about 9 mph (light breeze).

The calmer part of the year runs from around Apr 24 to Oct 8, with August the calmest month at about 6 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyJan 1 · 9 mphAug 5 · 6 mph
Wind speed (mph)Feels
Jan9light breeze
Feb9light breeze
Mar9light breeze
Apr8light breeze
May7calm
Jun7calm
Jul6calm
Aug6calm
Sep7calm
Oct8light breeze
Nov8light breeze
Dec9light breeze

Hazard calendar for Dover

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

Dover 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

Best time to visit Dover

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Dover throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around early June, Dover is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best time of year to visit Dover for general outdoor tourist activities is from late May to early October, with a peak score in the last week of August.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationAug 30 · 7.4

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.0poor
Feb0.0poor
Mar0.4poor
Apr3.1poor
May5.5fair
Jun6.5good
Jul6.5good
Aug6.9good
Sep6.9good
Oct4.8fair
Nov1.8poor
Dec0.1poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Dover for hot-weather activities is from mid June to mid September, with a peak score in the last week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 24 · 6.5

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Dover, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 79°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 32°F), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Dover sees daytime highs around 79°F and nights near 64°F. Pack sun protection. Worth having: light clothes and rain gear. About 11 days see rain.

Sea temperature near Dover

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea at the nearest coast (about 14 mi away) 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 (midday) in Dover by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Dover 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

Average hourly UV index in Dover

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in July the burn window is concentrated in the middle of the day: about 7.5 hours a day reach index 3 (protection recommended), and 3 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb00
Mar3.50
Apr5.50
May7.53
Jun7.53.5
Jul7.53
Aug50
Sep5.50
Oct1.50
Nov00
Dec00
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Dover typically lasts about 242 days, from around March 28 to November 24 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 19 to October 27.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonFeb 1010%Mar 2850%Apr 1990%Oct 2790%Nov 2450%Jan 3010%
Frost-free chance (%)Frost nights
Jan1231
Feb1328
Mar3331
Apr8416
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct953
Nov6430
Dec2631

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Dover banks about 2,402 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr2
May180
Jun467
Jul665
Aug623
Sep387
Oct77
Nov0
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Dover receives about 4.0 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 1.5 and 6.2 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 14 to Sep 21. The brightest month is July, averaging about 6.0 kWh/m² (intense).

The dimmest month is December, down near 1.6 kWh/m² — roughly 74% less than the July peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 26.2 kWhDec 161.5 kWh
Solar energy (kWh/m²)Level
Jan1.9Dim
Feb2.9Moderate
Mar4.0Bright
Apr5.0Bright
May5.6Bright
Jun6.0Bright
Jul6.1Intense
Aug5.4Bright
Sep4.2Bright
Oct2.9Moderate
Nov1.9Dim
Dec1.5Dim

Where is Dover?

Dover sits at 43.2°N, 70.9°W, 62 ft above sea level, in United States. The nearest listed city is Rochester, 8.7 mi away.

Topography around Dover

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

Within 2 miles, the terrain around Dover has only modest variations in elevation — a maximum elevation change of 315 ft around an average of 121 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 696 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,943 ft.

The land around Dover is covered by trees (62%) and grassland (20%) within 2 miles, trees (75%) within 10 miles, and trees (67%) and water (27%) within 50 miles.

2 miles
315 ft
10 miles
696 ft
50 miles
2,943 ft
treesgrasslandcroplandartificial surfaceswaterwetland
Nearby: Rochester 8.7 mi · Portsmouth 9.9 mi · Sanford 17 mi · Amesbury 24 mi · Newburyport 27 mi · Biddeford 29 mi · Saco 30 mi · Derry Village 30 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 Dover (43.1979°, -70.8737°, elevation 62 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).