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Forecast confidence: Medium · models disagree by 7°F

Boulder weather

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Heavy drizzle,rain likely tomorrow

NWS, the American and the European model put Boulder's high today between 78° and 85°, a 7° split. Tomorrow looks rain around 74°, with a 100% chance of rain.

81°58°
74°54°
69°50°
72°49°
77°53°
76°54°
Todaysplit ±7°Tomorrowsplit ±6°Sundaysplit ±8°Mondaysplit ±9°Tuesdaysplit ±8°Wednesdaymodels agree
NWSNational Blend (NBM)
70°
Light drizzle
Feels 69° · Wind 4 mph · Humidity 58%
AmericanNOAA GFS
78°
Overcast
Feels 72° · Wind 8 mph · Humidity 26%
EuropeanECMWF
70°
Drizzle
Feels 70° · Wind 5 mph · Humidity 56%

Latest for Boulder: NWS (National Blend (NBM)): 70° Light drizzle · American (NOAA GFS): 78° Overcast · European (ECMWF): 70° Drizzle.

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Boulder weather alerts and warnings

active National Weather Service watches, warnings and advisories

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Boulder weather in numbers

from 30 years of measured normals

Boulder swings 71°F across the year, from 86°F highs in July to 15°F lows in January, and May is usually the wettest month in a year that brings about 20 in of precipitation.

Warmest month
July
86°F average high
Coldest month
January
15°F average low
Wettest month
May
20 in a year
Below freezing
5 months
January, February, March, November and December
Comfortable
2 months
June and October
Residents
107,000
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The weather map: all three models at once

NWS, American, European side by side around Boulder and nearby towns.Live rain radar →
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Boulder hourly forecast: next 14 hours

consensus of the three models

Rain in the next 24 hours, model by model

each model's own hourly precipitation, side by side

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Boulder 10-day forecast, out to 14 days

where the models agree, and where they split
Today
Heavy drizzle
81° 58°
±7°
Tomorrow
Rain
74° 54°
±6°
Sun
Light drizzle
69° 50°
±8°
Mon
Light drizzle
72° 49°
±9°
Tue
Light drizzle
77° 53°
±8°
Wed
Light drizzle
76° 54°
models agree
Thu
Partly cloudy
78° 54°
models agree
Fri
Light drizzle
80° 56°
±11°
Sat
Light drizzle
79° 57°
±10°
Sun
Mostly clear
79° 53°
±4°
Mon
Light drizzle
75° 52°
models agree
Tue
Cloudy
80° 50°
±14°
Wed
Cloudy
82° 54°
models agree
Thu
Cloudy
83° 59°
models agree

Boulder, Colorado (CO) is at its warmest in Jul (average highs near 86°F) and coldest in Jan (lows around 15°F), with roughly 20 in of precipitation across the year. Below, compare what NWS, American, European forecast for Boulder right now, and see exactly where they disagree.

We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in United States before you trust any single number.

Boulder climate by month

average daytime high and overnight low across a typical year
Jan
33°
15°
Feb
41°
15°
Mar
46°
22°
Apr
58°
32°
May
67°
43°
Jun
78°
54°
Jul
86°
57°
Aug
84°
58°
Sep
79°
51°
Oct
66°
41°
Nov
48°
26°
Dec
45°
26°

Which forecast is most accurate in Boulder?

CheckWeather Score, graded against the weather that actually happened
ProviderCheckWeather-scoreTempWindRainRun by
European logo
European ★ Best
90
/100rank #1
95±0.5°F95±1.4 mph8290% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American logo
American
73
/100rank #2
78±2.2°F92±2.6 mph5374% hitNOAA / NCEP (United States)College Park, Maryland, USA

The CheckWeather Score blends temperature, wind and rain accuracy, each measured against ERA5 (the recorded weather) over the last 30 days across 1999 cities. Lower error means a higher score. See which forecast model is most accurate in United States, how we measure forecast accuracy, or which model each weather app uses.

What do you think of the forecasts?

your vote counts

The accuracy above is the measured record. This is your opinion: which forecast service do you trust most in United States? Give each 1 to 5 stars.

NWSNational Blend (NBM)
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AmericanNOAA GFS
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EuropeanECMWF
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One vote per service. Anonymous: we store no personal data, only a one-way hash of your connection for a day to stop double votes.

Where the models disagree

temperature and rain, judged separately
DayTemperatureRain
Today±7°78° to 85°±56%30% to 86% chance
Tomorrow±6°71° to 78°±58%42% to 100% chance
Sun±8°64° to 72°±47%43% to 90% chance
Mon±9°67° to 76°±11%24% to 35% chance
Tue±8°74° to 81°±1%30% to 31% chance

The models often agree on temperature and still split on rain, and rain is usually what decides whether a plan survives. A wide rain range means the shower is genuinely uncertain, not that the forecast is wrong.

Sunrise and sunset in Boulder

today, local time
Sunrise
06:45
Sunset
19:04
Daylight
12h 19m

Common questions

What's the weather in Boulder today?
On this page we show what NWS, American, European each forecast for Boulder today, side by side and updated live. When all three agree the forecast is reliable; when they split, we flag it so you know the day is genuinely less certain.
Will it rain in Boulder today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Boulder and flag the days where the models disagree on whether showers actually arrive, which is exactly when a single app can catch you out.
Which forecast is most accurate for Boulder?
Over the last 30 days, the European model has been the most accurate for Boulder (CheckWeather Score 90/100), ahead of the American at 73. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in Boulder?
July is typically the warmest month in Boulder, with average highs around 86°F.
How cold does Boulder get?
The coldest month in Boulder is January, when overnight lows average about 15°F.
How much rain does Boulder get?
Boulder sees roughly 20 in of precipitation a year, with May usually the wettest month.

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