Ontario, California weather

United States · America/Los_Angeles · 34.06, -117.65

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Ontario, California 7 day forecast

A week of highs, lows, rain chances, wind, and UV for Ontario, California, with a plain note about how much to trust each day.

The week at a glance

No day this week currently shows a strong rain signal.

Source updated: 7:05:18 PM · WeatherSignal checked: 7:05:18 PM

Source: Open-Meteo (national weather-service models)

Today
Clear sky
89° / 86°
Rain:
0% · 0.00″
Wind:
14 mph
UV:
6.0
Sun:
11:00 PM to 11:00 AM
High confidence: temperatures should be close, timing may shift by an hour or two.
Tomorrow
Clear sky
86° / 65°
Rain:
0% · 0.00″
Wind:
11 mph
UV:
6.1
Sun:
11:00 PM to 11:00 AM
High confidence: temperatures should be close, timing may shift by an hour or two.
Sunday, Oct 18
Overcast
84° / 66°
Rain:
0% · 0.00″
Wind:
9 mph
UV:
6.3
Sun:
11:00 PM to 11:00 AM
Moderate confidence: the pattern is reliable, the details are not settled.
Monday, Oct 19
Clear sky
82° / 66°
Rain:
0% · 0.00″
Wind:
10 mph
UV:
0.4
Sun:
11:00 PM to 11:00 AM
Moderate confidence: the pattern is reliable, the details are not settled.
Tuesday, Oct 20
Clear sky
79° / 62°
Rain:
0% · 0.00″
Wind:
6 mph
UV:
0.0
Sun:
11:00 PM to 11:00 AM
Lower confidence: a long range outlook, useful for planning direction, not for exact numbers.
Wednesday, Oct 21
Clear sky
67° / 55°
Rain:
0% · 0.00″
Wind:
7 mph
UV:
0.0
Sun:
11:00 PM to 11:00 AM
Lower confidence: a long range outlook, useful for planning direction, not for exact numbers.
Thursday, Oct 22
Clear sky
63° / 56°
Rain:
0% · 0.00″
Wind:
4 mph
UV:
0.0
Sun:
11:00 PM to 11:00 AM
Lower confidence: a long range outlook, useful for planning direction, not for exact numbers.

Forecast confidence drops the further out you look. Use days five through seven to decide whether to keep a plan flexible, not to schedule around an exact hour.

Planning your week in Ontario, California

The warmest afternoon ahead is today, reaching about 89°F.
The coldest night ahead dips to about 55°F.
This is a dry stretch — most days show rain chances under 20%, good for outdoor plans.
UV reaches 6 on the sunniest day — sunscreen is worth it if you will be outside around midday.

Common questions about Ontario, California weather

How accurate is the Ontario, California forecast?: The next 48 hours are usually reliable on temperature and sky cover, with timing that can shift by an hour or two. Days three and four are dependable for the overall pattern. Beyond that, treat the numbers as a planning direction rather than a promise — we label confidence on every day so you can judge for yourself.
What is the best day this week in Ontario, California?: No day in the current outlook has a rain chance above 40%, so conditions look favorable for outdoor plans across the week.
Where does this forecast come from?: Forecast values come from national weather model data, and official warnings come from the National Weather Service. We show the source and the last-updated time on every page, and we never invent a number the source did not publish — missing measurements are hidden, not guessed.
How often is this page updated?: The forecast refreshes whenever the source model publishes new data, typically several times a day. The freshness note near the top of the page shows exactly when the numbers you are looking at were issued.

More weather for Ontario, California

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