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CheckWeather USAltadena
Forecast confidence: High · models disagree by 4°F

Altadena weather

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Mostly clear,rain likely tomorrow

NWS, the American and the European model agree on a high near 88° in Altadena today. Tomorrow looks light rain around 78°, with a 94% chance of rain.

88°60°
78°69°
88°69°
92°74°
97°78°
95°78°
Todaymodels agreeTomorrowsplit ±5°Mondaysplit ±8°Tuesdaysplit ±7°Wednesdaysplit ±9°Thursdaysplit ±5°
NWSNational Blend (NBM)
86°
Mostly clear
Today 86°·Low 62°·Rain 0%
AmericanNOAA GFS
89°
Cloudy
Today 89°·Low 57°·Rain 0%
EuropeanECMWF
88°
Clear
Today 88°·Low 63°·Rain 6%

The weather map: all three models at once

NWS, American, European side by side around Altadena and nearby towns.Live rain radar →
Loading the three model maps…

Next 14 hours

consensus of the three models

14-day forecast

where the models agree, and where they split
Today
Mostly clear
88° 60°
models agree
Tomorrow
Light rain
78° 69°
±5°
Mon
Mostly clear
88° 69°
±8°
Tue
Cloudy
92° 74°
±7°
Wed
Cloudy
97° 78°
±9°
Thu
Clear
95° 78°
±5°
Fri
Clear
89° 73°
±5°
Sat
Partly cloudy
84° 68°
models agree
Sun
Mostly clear
86° 67°
±10°
Mon
Clear
87° 69°
±4°
Tue
Light drizzle
90° 70°
±11°
Wed
Cloudy
91° 76°
models agree
Thu
Drizzle
87° 73°
±8°
Fri
Clear
87° 72°
±12°

Altadena, CA is at its warmest in Jul (average highs near 91°F) and coldest in Feb (lows around 43°F), with roughly 36 in of precipitation across the year. Below, compare what NWS, American, European forecast for Altadena 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.

Altadena climate by month

average daytime high and overnight low across a typical year
Jan
59°
44°
Feb
58°
43°
Mar
59°
44°
Apr
68°
48°
May
70°
52°
Jun
77°
58°
Jul
91°
69°
Aug
88°
68°
Sep
83°
64°
Oct
80°
61°
Nov
69°
51°
Dec
66°
50°

Which forecast is most accurate in Altadena?

CheckWeather Score — graded against the weather that actually happened
ProviderCheckWeather Score🌡 Temp💨 Wind🌧 RainRun by
American logo
American ★ Best
95
/100rank #1
90±1.0°F96±1.1 mph100100% hitNOAA / NCEP (United States)College Park, Maryland, USA
European logo
European
94
/100rank #2
86±1.4°F98±0.7 mph100100% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom

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.

Where the models disagree

temperature and rain, judged separately
DayTemperatureRain
Today±4°86° to 89°±6%0% to 6% chance
Tomorrow±5°76° to 81°±50%44% to 94% chance
Mon±8°86° to 94°±10%3% to 13% chance
Tue±7°89° to 95°±2%6% to 8% chance
Wed±9°93° to 102°±2%10% to 12% 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 Altadena

today, local time
Sunrise
06:29
Sunset
19:13
Daylight
12h 44m

Common questions

What's the weather in Altadena today?
On this page we show what NWS, American, European each forecast for Altadena 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 Altadena today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Altadena 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 Altadena?
Over the last 30 days, the American model has been the most accurate for Altadena (CheckWeather Score 95/100), ahead of the European at 94. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in Altadena?
July is typically the warmest month in Altadena, with average highs around 91°F.
How cold does Altadena get?
The coldest month in Altadena is February, when overnight lows average about 43°F.
How much rain does Altadena get?
Altadena sees roughly 36 in of precipitation a year, with February usually the wettest month.

Nearby

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