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Rialto, California Weather

Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →

Rialto weather forecast — hour by hour, 7-day outlook, NOAA radar

Rialto, CA
Sunday, July 5 at 9:59 AM
78
°
Mostly Clear
Feels like
76°
Humidity
37%
Wind
7 mph
Sunrise
10:43 PM
Sunset
1:04 PM
Rialto, CA
Hour by hour · 24h
24-Hour ForecastRialto, CA: 24-hour forecast. Temperatures range from 60 to 91 degrees Fahrenheit.
L 60°H 91°
Rialto, CA
7-day forecast
  1. Today
    Jul 5
    Overcast
    —
    —
    91°65°—
  2. Monday
    Jul 6
    Clear
    —
    —
    92°60°+1°
  3. Tuesday
    Jul 7
    Clear
    —
    —
    95°64°+3°
  4. Wednesday
    Jul 8
    Clear
    —
    —
    99°77°+4°
  5. Thursday
    Jul 9
    Clear
    —
    —
    99°78°0°
  6. Friday
    Jul 10
    Clear
    —
    —
    97°77°-2°
  7. Saturday
    Jul 11
    Overcast
    —
    —
    95°77°-2°
Rialto, CA
Next 24 hours · Mild now
HOT 90°50°75°100°6a12p6p12anow 77°high 91°low 60°
Rialto, CA
Anemometer · 24h winds · from true
NESW
From · True
WSW
253° · backing 51°
Direction
WSW
253°
Sustained
7
mph
Gust
8
mph
Peak 24h
17
avg 5
Beaufort · 2 · LIGHT BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 5 · pk 17 @ 7:00p
01020MPHB1B2B3B4B5-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 162SUSTGUST
−24h−18h−12h−6hnow
A whisper of wind — leaves barely shift on the trees.
Rialto, CA
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
965.8
+1.2 mb in 3h · rising · 28.52 inHg
Now
965.8
mb
3h
+1.2
mb
12h
-0.2
mb
24h
-2.8
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 965–969
960965970975-21h-18h-15h-12h-9h-6h-3h-24hNOW969.2964.9966.1
−24h−18h−12h−6hnow
The low is filling — pressure climbing out of storm territory.
Rialto, CA
Air quality
36
AQI
Good
→+1 in 6h

AQI 36 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 10.1 µg/m³, PM10 at 13.2 µg/m³ — typical background levels with no transport signature.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.

PM 2.5DRIVERGood
10.1μg/m³
PM 10Good
13μg/m³
NO₂Good
7μg/m³
OzoneModerate
64μg/m³
UV IndexModerate
4.3

What's driving it

Ozone × UV × Sky

Ozone at AQI 30 now. With UV 8.6 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 34 around 1 PM.

Present
AQI 30
UV peak
8.6 at 1 PM
Sky at peak
clear
Projected peak
AQI 34

PM × Wind × Precip

PM2.5 at 10.1 µg/m³, PM10 at 13.2 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.77
Wind
light
Recent rain
0h in last 6h
Pattern
background

Trends

Seven days of AQI and PM2.5.

Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).

7-DAY AQI TREND50100SUNMONTUEWEDTHUFRISATSUN7-DAY PM2.5 TREND · μg/m³300
Rialto, CA
Sky cover · visibility · 24h
Cloud cover
23%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
82.4mi
UNLIMITED
169 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
16:59 UTC · Rialto, CA · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
16:59 UTC · Rialto, CA · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Rialto, CA
Satellite · infrared · animated
Rialto, CA
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Rialto, CA
Almanac · Sunday, July 5
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:15 AM
Sunrise
10:43 PM
Daylight
14h 21m
Sunset
1:04 PM
Civil dusk
8:34 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Rialto, CA
The moon
Waning Gibbous
71% illuminated
Moonrise
11:05 PM
Moonset
11:08 AM
In sign
♓︎ Pisces
Rialto, CA
Microseason
Jul 1–5

Summer heat deepens across the valleys

weather
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Rialto at a glance

  • Today vs. normal: 78°F — typical for the season
  • Last frost: March 12 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP codes: 92376, 92377

16-Day Forecast — Rialto

  1. Sun91°65°1%
  2. Mon92°60°1%
  3. Tue95°64°0%
  4. Wed99°77°0%
  5. Thu99°78°0%
  6. Fri97°77°0%
  7. Sat95°77°1%
  8. Sun96°76°1%
  9. Mon97°78°7%
  10. Tue96°82°13%
  11. Wed100°82°7%
  12. Thu100°82°13%
  13. Fri108°86°14%
  14. Sat114°93°12%
  15. Sun100°86°19%
  16. Mon98°81°18%

Forecast data from Open-Meteo (CC BY 4.0).

Live wind & temperature near Rialto

Right now in the garden

Peak growing season

As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

January 1–5: New year in coastal mist.January 6–10: Hills hold the winter cold.January 11–15: Light lengthens over wet earth.January 16–20: The green pulse quickens.January 21–25: Spring green spreads inland.January 26–31: Winter's grip releases.February 1–5: Fog lifts, flowers open.February 6–10: Blooms erupt across chaparral.February 11–15: Winter blooms at their peak.February 16–20: Rivers recede, flowers spread.February 21–25: Earth warms, flowers rush upslope.February 26–28: Spring advances on cool winds.March 1–5: Grass and trees bud and break.March 6–10: Insects wake and feed.March 11–15: Blossoms crown the hillsides.March 16–20: Monarch chrysalis emergence.March 21–25: Light overtakes dark at equinox.March 26–31: California poppy ablaze.April 1–5: Spring rain feeds the seedlings.April 6–10: Warblers flood the understory.April 11–15: Allen's hummingbirds in courtship dives.April 16–20: Coastal fog settles; sun breaks midday.April 21–25: Oak canopies full and green.April 26–30: Chaparral awakens after spring rains.May 1–5: Coastal wildflowers at their peak.May 6–10: Gray whales complete their migration north.May 11–15: Redwood coast in cool shade.May 16–20: Fog and sun in daily rhythm.May 21–25: Summer approaches; hills turn gold.May 26–31: Dry season begins; tule fog in valleys.June 1–5: Coastal fog thickens at dawn.June 6–10: California poppies fade as heat rises.June 11–15: Summer solstice light stretched thin.June 16–20: Bay laurel fragrance sweetens shade.June 21–25: Longest daylight, driest air.June 26–30: Fog banks mask the turning tide.July 1–5: Summer heat deepens across the valleys.July 6–10: Warm winds drive dryness inland.July 11–15: Pacific high settles in firmly.July 16–20: Young hawks take to the thermals.July 21–25: Peak fire season, peak heat.July 26–31: Chaparral poised for ignition.August 1–5: August begins in scorching stillness.August 6–10: Autumn's first cool breath arrives.August 11–15: Cool winds signal the turning year.August 16–20: Evening cicada chorus.August 21–25: Marine layer descent.August 26–31: Monarch staging begins.September 1–5: Fire season intensity.September 6–10: Dew on drying grasses.September 11–15: Raptor passage begins.September 16–20: Equinox descent.September 21–25: Ceanothus blooms again.September 26–30: Insects retreat below.October 1–5: Creeks begin to whisper.October 6–10: Santa Ana wind season.October 11–15: Wildflower anticipation.October 16–20: Chaparral embers glow.October 21–25: First atmospheric river looms.October 26–31: Rains return at last.November 1–5: Coast live oak leaves turn amber.November 6–10: California lilac blooms in winter light.November 11–15: First rain greens the chaparral.November 16–20: Coastal fog thickens as storms approach.November 21–25: Thanksgiving rains swell the valleys.November 26–30: Autumn's last breath yields to winter.December 1–5: December arrives, storms accelerate.December 6–10: Winter solstice season intensifies.December 11–15: Deep winter: rivers at flood stage.December 16–20: Winter salmon runs peak in northern rivers.December 21–25: Winter solstice: the sun turns.December 26–31: Year's end in wind and rain.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · July 1–5

Summer heat deepens across the valleys

Inland temperatures exceed 95°F regularly; fire danger reaches moderate to high across most of the region.

Day 186 of 365 · Wedge 37 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
Marchlettuce, peas, spinach, radishes—
Aprillettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash—
Maytomatoes, peppers, beans, squashlettuce, peas, radishes
Junetomatoes, peppers, beans, squashlettuce, peas, radishes
July—tomatoes, beans, summer squash
August—tomatoes, beans, summer squash
September—tomatoes, beans, summer squash
Octoberfall brassicas, garlic (overwinter), carrotswinter squash, tomatoes (last)
Novemberfall brassicas, garlic (overwinter), carrots—
December——

A year in weather

In Rialto, August runs warmest near 80°F and January coldest around 52°F, while February is the wettest month (3.4 inches) and August the driest (0.0 inches).

MonthMean tempPrecipRainy days
January52°3.3″11
February54°3.4″10
March57°3.0″13
April62°1.5″10
May67°0.5″7
June73°0.1″3
July79°0.1″1
August80°0.0″1
September76°0.1″2
October69°0.5″5
November59°1.6″8
December53°2.6″10

Regional context

Rialto's climate, from NOAA NCEI 1991-2020 station normals, pairs 52°F Januarys with 79°F Julys — a 27°F swing. About 16.7 inches of precipitation falls over roughly 82 days a year.

Cool-season fronts carry Rialto's rain: February logs 3.4 inches on 9.9 days, against August's 0.0 inches on 0.9 — winter does the heavy lifting in Rialto. That cool-season-wet pattern aligns Rialto with places like Muscoy, CA, Bloomington, CA and Fontana, CA.

Rialto rarely sees a hard freeze — its coldest month sits near 52°F — so planting spans most of the calendar. Heat peaks in August around 80°F, which confines cool-season crops to the shoulders of summer. Across Rialto, elevation and tree cover drive a 4-7°F spread in Rialto's overnight lows.

Similar climates: Muscoy, CA, Bloomington, CA, Fontana, CA, San Bernardino, CA, Colton, CA.

Naturalist notes

By late May, western fence lizards are emerging for longer periods on sun-warmed boulders and retaining walls across the inland basin, timing their activity to the days when afternoon soil surfaces reliably exceed 75°F.

Toland's night-blooming cereus, a native cactus of the inland foothills, opens its large white flowers for a single night in mid-to-late June, an event that typically coincides with the first sustained heat of summer.

Frequently asked

When does it freeze in Rialto?
Frost typically leaves Rialto by mid-March and returns to Rialto near mid-December.
What is the rainy season in Rialto?
February is the wettest month in Rialto, about 3.4 inches on average; the year totals roughly 17 inches.
What is the warmest month in Rialto?
On average August tops the year in Rialto at about 80°F.
What is the coldest month in Rialto?
The coldest stretch in Rialto falls in January, around 52°F on average.
When can I start a vegetable garden in Rialto?
In Rialto, sow peas and hardy greens around mid-March; Rialto's tomatoes and peppers wait two weeks more.
How many rainy days does Rialto get?
Rialto records around 82 days of measurable precipitation annually.
What hardiness zone is Rialto?
With January around 52°F, Rialto's zone reflects that minimum — the USDA ZIP map confirms Rialto's band.
What is the 10-day forecast for Rialto?
Rialto's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
Will it rain this week in Rialto?
See this week's day-by-day rain chances for Rialto in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Rialto?
Current conditions for Rialto and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Rialto forecast updated?
The Rialto forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Rialto?
Today's sunrise and sunset times for Rialto are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
How accurate is the weather forecast for Rialto?
The next few days in Rialto's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

In Rialto, California, the hot-summer Mediterranean climate runs from about 52°F in January to 79°F in July, a 27°F seasonal range.

Rialto sees close to 17 inches of precipitation annually, falling across some 82 wet days.

Rialto's 27°F range, set by its 34.1°N position, drives frost timing and what thrives in Rialto.

All cities in California →

Riverside, CA weather →

ZIP codes in Rialto

  • 92316
  • 92376
  • 92377

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.