Climate and average weather in Brighton

In Brighton, the summers are hot, fairly dry, and mostly clear and the winters are cold, snowy, and mostly clear.

Best: early September to late October

Over the course of the year, the temperature in Brighton typically varies from 19°F to 89°F, and is rarely below 3°F or above 97°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Brighton for warm-weather activities are from early May to mid June and early September to late October.

Hottest
Jul
89°
Coldest
Jan
19°
Wettest
May
2.5 in
Driest
Feb
0.5 in
Rain / yr
14.1 in
65 wet days
Daylight
9.2–14.8 h
shortest–longest
Elevation
4,984 ft
40.0°N
Clearest
Sep
38% cloud

Brighton is city in and county seat of Adams County, Colorado, United States.

Density
716/km²
people per km²
Founded
1887

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

Brighton 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 early September to late October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.6 months, from June 1 to September 18, with daily high temperatures above 77°F. The hottest month of the year in Brighton is July, with an average high of 89°F and low of 61°F.

The cool season lasts 3.3 months, from November 22 to February 28, with daily high temperatures below 50°F. The coldest month of the year in Brighton is January, with an average low of 19°F and high of 42°F.

Days typically run about 26°F warmer than nights year-round.

20°40°60°80°100°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan4219
Feb4622
Mar5629
Apr6337
May7246
Jun8355
Jul8961
Aug8760
Sep7951
Oct6538
Nov5227
Dec4220

How hot and cold Brighton 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 hottest afternoons, once humidity is folded in, Brighton feels like about 90°F (around July 14). About 5 days a year carry some heat stress, peaking in July.

On the coldest nights, wind chill pulls the feels-like down to about 10°F (around January 1), with roughly 180 freezing days a year (feels-like at or below 32°F) 71 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)
Jan42421119
Feb46461422
Mar56562329
Apr63633137
May72724346
Jun83835555
Jul89896161
Aug87876060
Sep79795051
Oct65653438
Nov52522127
Dec42421220

Average hourly temperature in Brighton

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 89°F, and coldest before dawn in January, near 19°F.

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

Brighton 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
Jan42° / 19°0.53.33.59.50.4
Feb46° / 22°0.53.63.510.41.5
Mar56° / 29°1.35.43.411.74.3
Apr63° / 37°2.07.63.2135.8
May72° / 46°2.59.50.614.26.7
Jun83° / 55°1.57014.86.3
Jul89° / 61°1.36.9014.54.6
Aug87° / 60°1.25.7013.65.5
Sep79° / 51°1.04.20.412.37.7
Oct65° / 38°1.25.11.510.96.9
Nov52° / 27°0.74.13.39.83.4
Dec42° / 20°0.533.29.20.5

Chance of rain

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

Brighton gets about 14.1 in of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.

The wetter season lasts 4.9 months, from around Mar 20 to Aug 15, peaking in May at about 33% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jan 7.

May is the wettest month by volume, with 2.5 in over about 10 wet days; February is the driest, with 0.5 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetMay 25 · 33%Jan 7 · 10%
Rain on a day (%)Rain days
Jan103
Feb134
Mar185
Apr258
May3110
Jun247
Jul227
Aug186
Sep154
Oct155
Nov144
Dec103

Monthly rainfall

Over a full year, Brighton collects about 14.1 in of rain across 65 wet days — roughly 1.2 in in an average month.

It doesn’t fall evenly. May is the wettest month with 2.5 in, while February is the driest at just 0.5 in. The three wettest months alone bring about 42% of the year’s total, and some of the cold-season precipitation falls as snow.

00.511.522.53JanFebMarAprMayJunJulAugSepOctNovDec0.50.51.32.02.51.51.31.21.01.20.70.5
Rainfall (in)Rain daysSnow days
Jan0.534
Feb0.544
Mar1.353
Apr2.083
May2.5101
Jun1.570
Jul1.370
Aug1.260
Sep1.040
Oct1.252
Nov0.743
Dec0.533

Snow in Brighton

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.

Brighton averages about 23 snowy days a year. Snow season runs roughly Sep 21 to May 19 — about 7.9 months.

April is snowiest, with roughly 3 days of snow and an estimated 6 in of snowfall. Over the year that adds up to an estimated 41 in of snow.

0246JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonApr 1
Snow daysSnowfall (in)
Jan45
Feb44
Mar310
Apr36
May12
Jun00
Jul00
Aug00
Sep00
Oct23
Nov37
Dec35

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Brighton, 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 June 12 and lasts for 7.2 months, ending around January 16. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 75% of the time on average.

The cloudier part of the year begins around January 17 and lasts for 4.8 months, ending around June 11. The cloudiest month is April, when it is overcast or mostly cloudy 47% 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%JanFebMarAprMayJunJulAugSepOctNovDecSep 10 · 76%Apr 15 · 51%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearer
Clearer (%)Cloudier (%)
Jan6436
Feb6139
Mar6040
Apr5347
May5446
Jun6733
Jul7030
Aug7030
Sep7525
Oct7228
Nov6931
Dec6832

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 9, brings about 14 h 48 min of light; the shortest, around January 1, only 9 h 12 min — a swing of roughly 5 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.57:254:52
Feb10.47:015:27
Mar11.76:195:59
Apr13.05:286:31
May14.24:497:02
Jun14.84:357:24
Jul14.54:487:22
Aug13.65:166:51
Sep12.35:466:01
Oct10.96:175:12
Nov9.86:524:37
Dec9.27:204:31

Sunny days

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

Brighton averages about 14 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 9 and 18 days.

The sunnier stretch runs 5.6 months, from around Aug 12 to Jan 29. The sunniest month is October, with roughly 18 sunny days (bright).

The greyest month is May, down near 9 sunny days — about 50% fewer than the October peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedbrightOct 1318 daysMay 209 days
Sunny daysSky
Jan15Mixed
Feb12Mixed
Mar13Mixed
Apr9Mixed
May9Mixed
Jun12Mixed
Jul13Mixed
Aug14Mixed
Sep17Bright
Oct18Bright
Nov16Bright
Dec16Bright

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 Brighton, the air stays dry or comfortable essentially all year. Even in July, the muggiest month, it feels humid or worse only about 3% of the time — humidity is not something you need to plan around here.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDeccomfortabledry
Dry (%)Comfortable (%)Humid (%)
Jan10000
Feb10000
Mar10000
Apr10000
May10000
Jun9550
Jul79183
Aug84151
Sep9820
Oct10000
Nov10000
Dec10000

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 Brighton is typically calm, near 6 mph, and varies little with the seasons.

The windier part of the year lasts 4.2 months, from around Feb 13 to Jun 20. The windiest month is April, averaging about 7 mph (calm).

The calmer part of the year runs from around Jun 21 to Feb 12, with August the calmest month at about 5 mph.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezeApr 14 · 7 mphAug 6 · 5 mph
Wind speed (mph)Feels
Jan5calm
Feb6calm
Mar6calm
Apr7calm
May6calm
Jun6calm
Jul5calm
Aug5calm
Sep5calm
Oct5calm
Nov5calm
Dec5calm

Best time to visit Brighton

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid October, Brighton is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

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 times of year to visit Brighton for general outdoor tourist activities run from early May to mid June and again from early September to late October, with a peak score in the last week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationSep 24 · 8.1

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
Jan0.4poor
Feb1.6poor
Mar4.2fair
Apr5.8good
May6.7good
Jun6.2good
Jul4.7fair
Aug5.5good
Sep7.6ideal
Oct6.8good
Nov3.4poor
Dec0.5poor

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 Brighton for hot-weather activities is from early June to late September, with a peak score in the last week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 31 · 8.1

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 Brighton, 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 89°F), the essentials are light clothes and sun protection. In the cold season around January (highs near 42°F), pack a warm layer and a heavy coat.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Brighton sees daytime highs around 89°F and nights near 61°F. Pack light clothes and sun protection. About 7 days see rain.

UV index (midday) in Brighton 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 Brighton peaks around July 12 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 12UV 11Dec 23UV 2
UV index (midday)Level
Jan2Low
Feb4Moderate
Mar7High
Apr6High
May7Very high
Jun10Extreme
Jul11Extreme
Aug10Very high
Sep7Very high
Oct5High
Nov3Moderate
Dec2Low

Average hourly UV index in Brighton

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 9 hours a day reach index 3 (protection recommended), and 6 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
Feb3.50
Mar62
Apr6.52
May7.54
Jun96
Jul96
Aug85.5
Sep6.53
Oct50
Nov20
Dec00

Air quality in Brighton by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Brighton is worst in August — around 21 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (May, 13 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateAug 1620 µg/m³May 1113 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb15Moderate
Mar16Moderate
Apr13Moderate
May13Moderate
Jun14Moderate
Jul14Moderate
Aug21Moderate
Sep13Moderate
Oct15Moderate
Nov15Moderate
Dec16Moderate
Almanac & agriculture

Growing season

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

The growing season in Brighton typically lasts about 218 days, from around March 28 to October 31 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 30 to October 10.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonJan 3010%Mar 2850%Apr 3090%Oct 1090%Oct 3150%Dec 710%
Frost-free chance (%)Frost nights
Jan731
Feb1328
Mar3731
Apr7429
May970
Jun1000
Jul1000
Aug1000
Sep1000
Oct7922
Nov2930
Dec831

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. Brighton banks about 2,905 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
Apr20
May277
Jun574
Jul781
Aug716
Sep450
Oct88
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.

Brighton receives about 5.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.4 and 7.5 kWh/m².

The brighter stretch of the year lasts 6.4 months, from around Mar 14 to Sep 23. The brightest month is June, averaging about 7.4 kWh/m² (intense).

The dimmest month is December, down near 2.4 kWh/m² — roughly 67% less than the June peak.

0123456789JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 297.5 kWhDec 152.4 kWh
Solar energy (kWh/m²)Level
Jan2.8Moderate
Feb3.8Moderate
Mar5.2Bright
Apr6.1Intense
May6.7Intense
Jun7.4Intense
Jul7.3Intense
Aug6.6Intense
Sep5.4Bright
Oct4.0Moderate
Nov2.9Moderate
Dec2.4Moderate

Where is Brighton?

Brighton sits at 40.0°N, 104.8°W, 4,984 ft above sea level, in United States. The nearest listed city is Northglenn, 11 mi away.

Topography around Brighton

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

Within 2 miles, the terrain around Brighton has only modest variations in elevation — a maximum elevation change of 194 ft around an average of 4,990 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 640 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,626 ft.

The land around Brighton is covered by artificial surfaces (34%), grassland (32%) and cropland (21%) within 2 miles, grassland (51%) and cropland (28%) within 10 miles, and grassland (48%), trees (22%) and cropland (20%) within 50 miles.

2 miles
194 ft
10 miles
640 ft
50 miles
9,626 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Northglenn 11 mi · Thornton 11 mi · Erie 13 mi · Commerce City 14 mi · Sherrelwood 14 mi · Lafayette 14 mi · Broomfield 15 mi · Westminster 16 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 Brighton (39.9853°, -104.8205°, elevation 4,984 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. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).