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Prosser, Washington Weather

Monsoon storms drench the south. Day 15 of summer. Read this microseason across nine climate regions →

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

Prosser, WA
Sunday, July 5 at 5:11 AM
59
°
Clear
Feels like
56°
Humidity
50%
Wind
1 mph
Sunrise
10:14 PM
Sunset
1:53 PM
Prosser, WA
Hour by hour · 24h
24-Hour ForecastProsser, WA: 24-hour forecast. Temperatures range from 59 to 90 degrees Fahrenheit.
L 59°H 90°
Prosser, WA
7-day forecast
  1. Today
    Jul 5
    Overcast
    —
    —
    90°59°—
  2. Monday
    Jul 6
    Overcast
    —
    —
    96°64°+6°
  3. Tuesday
    Jul 7
    Overcast
    —
    —
    101°65°+5°
  4. Wednesday
    Jul 8
    Overcast
    —
    —
    91°64°-10°
  5. Thursday
    Jul 9
    Partly Cloudy
    —
    —
    91°56°0°
  6. Friday
    Jul 10
    Mostly Clear
    —
    —
    93°60°+2°
  7. Saturday
    Jul 11
    Clear
    —
    —
    89°59°-4°
Prosser, WA
Next 24 hours · Cool now
HOT 90°50°75°100°12a6a12p6pnow 59°high 90°low 59°
Prosser, WA
Anemometer · 24h winds · from true
NESW
From · True
SSW
202° · backing 140°
Direction
SSW
202°
Sustained
1
mph
Gust
1
mph
Peak 24h
22
avg 5
Beaufort · 1 · LIGHT AIR
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 22 @ 9:00p
010MPHB1B2B3B4-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 104SUSTGUST
−24h−18h−12h−6hnow
A whisper of wind — leaves barely shift on the trees.
Prosser, WA
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
991.8
+0.8 mb in 3h · rising · 29.29 inHg
Now
991.8
mb
3h
+0.8
mb
12h
+2.3
mb
24h
+1.3
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 989–992
9809859909951000STORM|RAIN-21h-18h-15h-12h-9h-6h-3h-24hNOW992.0988.5991.8
−24h−18h−12h−6hnow
Deep low — expect rough seas, strong wind, and persistent rain.
Prosser, WA
Air quality
30
AQI
Good
↓-14 in 6h

AQI 30 (Good), driven by Ozone. AQI down 14 over the last 6 hours (gradual decline).

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

PM 2.5Good
2.5μg/m³
PM 10Good
3μg/m³
NO₂Good
8μg/m³
OzoneDRIVERGood
45μg/m³
UV IndexLow
0.0

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
Prosser, WA
Sky cover · visibility · 24h
Cloud cover
0%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
75.8mi
UNLIMITED
179 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
12:11 UTC · Prosser, WA · 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
12:11 UTC · Prosser, WA · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Prosser, WA
Satellite · infrared · animated
Prosser, WA
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Prosser, WA
Almanac · Sunday, July 5
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
4:36 AM
Sunrise
10:14 PM
Daylight
15h 39m
Sunset
1:53 PM
Civil dusk
9:32 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Prosser, WA
The moon
Waning Gibbous
73% illuminated
Moonrise
11:23 PM
Moonset
11:15 AM
In sign
♓︎ Pisces
Prosser, WA
Microseason
Jul 1–5

Monsoon storms drench the south

insect
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Prosser at a glance

  • Today vs. normal: 6°F below the seasonal normal for this latitude
  • Last frost: May 23 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP code: 99350

16-Day Forecast — Prosser

  1. Sun90°59°0%
  2. Mon96°64°0%
  3. Tue101°65°1%
  4. Wed91°64°0%
  5. Thu91°56°0%
  6. Fri93°60°0%
  7. Sat89°59°1%
  8. Sun94°58°1%
  9. Mon96°63°1%
  10. Tue107°68°4%
  11. Wed103°65°1%
  12. Thu88°67°3%
  13. Fri99°72°3%
  14. Sat104°68°6%
  15. Sun99°63°5%
  16. Mon97°61°3%

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

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: Deep freeze grips the high peaks.January 6–10: Ice thickens on alpine tarns.January 11–15: Springs stir beneath locked earth.January 16–20: Grouse call from the transition zone.January 21–25: First signals of the soil's turning.January 26–31: Stream water crystallizes thick.February 1–5: The year's coldest fortnight begins.February 6–10: East wind carries a subtle promise.February 11–15: Snowmelt springs whisper beneath ice.February 16–20: Red-wing calls rise from the wetlands.February 21–25: Rain begins to trace the snowline upward.February 26–28: Mist gathers in the warming canyons.March 1–5: Grass and trees stir from their sleep.March 6–10: Hibernators break through frozen ground.March 11–15: First blooms open to the spring sun.March 16–20: Mountain bluebirds return to the summits.March 21–25: Spring equinox at the divide.March 26–31: Aspen catkins burst in clusters.April 1–5: Thunderstorms rumble over granite peaks.April 6–10: Swallows and swifts slice the warming sky.April 11–15: Sandhill cranes call through the wetlands.April 16–20: Rainbows arch over the snowfields.April 21–25: New growth explodes across the montane.April 26–30: Last frost yields to summer growth.May 1–5: Wildflowers crest the high meadows.May 6–10: Summer monsoon clouds gather southward.May 11–15: Snowmelt crests toward the divide.May 16–20: High country wildflowers peak.May 21–25: Summer heat accelerates the growing season.May 26–31: Summer settles into the high country.June 1–5: Pikas hayfeeding in granite peaks.June 6–10: Glacier lily carpets the snowmelt.June 11–15: Paintbrush crowns the ridges.June 16–20: Thunderheads build by noon.June 21–25: Long light holds the peaks.June 26–30: Monsoon moisture drifts north.July 1–5: Monsoon storms drench the south.July 6–10: Wind builds through canyons.July 11–15: Lightning crowns every peak.July 16–20: Elk herds claim alpine meadows.July 21–25: Pika caches reach their peak.July 26–31: Monsoon pulses weaken northward.August 1–5: Summer heat breaks with monsoon.August 6–10: First frost creeps to peaks.August 11–15: Cool wind returns from north.August 16–20: Monsoon clouds gather over the peaks.August 21–25: The monsoon breaks into scattered showers.August 26–31: Summer insects thin as autumn wind rises.September 1–5: Elk descend from summer high meadows.September 6–10: Dew crystallizes on high grass at dawn.September 11–15: Hawks begin the long crossing southward.September 16–20: Equinox: darkness claims the high passes.September 21–25: Thunder retreats as the monsoon dies.September 26–30: First frost hardens the high valleys.October 1–5: October: the aspen stands reach their peak.October 6–10: Aspen gold slides downslope with the chill.October 11–15: Snow settles on the high passes.October 16–20: Elk bugling fades as rut nears its end.October 21–25: First hard frost grips the basin.October 26–31: Late rains settle into November patterns.November 1–5: Aspen canopy falls to earth.November 6–10: Granite bones emerge from cover.November 11–15: Earth begins to harden.November 16–20: Bare ranges hold silence.November 21–25: Snow returns to the peaks.November 26–30: North wind strips the landscape.December 1–5: Deep darkness settles over the ranges.December 6–10: Winter locks the high country.December 11–15: Elk withdraw to winter range.December 16–20: Ice thickens across frozen water.December 21–25: Winter solstice — the sun returns.December 26–31: The year closes in silence.🌱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

Monsoon storms drench the south

Monsoon established in southern Mountain West (New Mexico, southern Utah, Arizona north); afternoon downpours and lightning common.

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——
March——
April——
Maylettuce, peas, spinach, radisheslettuce, peas, radishes
Junelettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
Augusttomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
October—winter squash, tomatoes (last)
November——
December——

A year in weather

The year in Prosser tops out in July (~75°F) and dips lowest in December (~33°F), with December wettest at 1.3 inches and August driest at 0.2 inches.

MonthMean tempPrecipRainy days
January34°1.2″4
February38°0.9″3
March45°0.7″3
April52°0.7″2
May61°0.9″2
June67°0.7″2
July75°0.2″1
August73°0.2″1
September65°0.3″1
October53°0.8″3
November41°0.9″3
December33°1.3″4

Regional context

Per NOAA NCEI 1991-2020 normals, Prosser runs from a 34°F January mean to 75°F in July, a 42°F seasonal spread, with near 8.7 inches of precipitation across about 29 wet days.

Cool-season fronts carry Prosser's rain: December logs 1.3 inches on 4.2 days, against August's 0.2 inches on 0.8 — winter does the heavy lifting in Prosser. That cool-season-wet pattern aligns Prosser with places like Grandview, WA, Mabton, WA and Sunnyside, WA.

Prosser reaches its last hard frost near late-May; that is the cue for peas, lettuce, spinach, and radishes. Prosser's heat-lovers — tomatoes, peppers, squash — hold off until Prosser's frost risk clears, 10-14 days on. Frost returns to Prosser near early-October, ending the tender-crop season. Prosser's low ground holds frost later into spring than Prosser's benches, which run 3-5 days ahead.

Similar climates: Grandview, WA, Mabton, WA, Sunnyside, WA, Benton City, WA, Outlook, WA.

Frequently asked

When does it freeze in Prosser?
Frost typically leaves Prosser by mid-May and returns to Prosser near mid-October.
What is the rainy season in Prosser?
Rainfall in Prosser peaks in December near 1.3 inches, out of about 9 inches annually.
What is the warmest month in Prosser?
The warmest stretch in Prosser comes in July, around 75°F on average.
What is the coldest month in Prosser?
On average December is the chilliest month in Prosser, about 33°F.
When can I start a vegetable garden in Prosser?
Frost-hardy sowings begin at mid-May in Prosser; warm-season starts follow two weeks on.
How many rainy days does Prosser get?
Prosser averages about 29 days with measurable rain or snow each year.
What hardiness zone is Prosser?
Prosser's USDA zone comes from its December mean (33°F); enter the ZIP on the USDA lookup for the number.
What is the 10-day forecast for Prosser?
Prosser'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 Prosser?
See this week's day-by-day rain chances for Prosser in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Prosser?
Current conditions for Prosser and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Prosser forecast updated?
The Prosser forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Prosser?
Today's sunrise and sunset times for Prosser 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 Prosser?
The next few days in Prosser's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

Prosser, Washington has a warm-summer Mediterranean climate: January averages roughly 34°F, July about 75°F, 41°F between them.

In a typical year Prosser records about 9 inches of precipitation on around 29 days.

At 46.2°N, Prosser's 41°F summer-to-winter swing sets when Prosser's gardens wake and when frost returns.

All cities in Washington →

Richland, WA weather →

ZIP codes in Prosser

  • 99350

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.